diff --git a/alembic/versions/20260822_controlled_tally_purchase_posting_phase10.py b/alembic/versions/20260822_controlled_tally_purchase_posting_phase10.py
new file mode 100644
index 0000000..935c791
--- /dev/null
+++ b/alembic/versions/20260822_controlled_tally_purchase_posting_phase10.py
@@ -0,0 +1,64 @@
+"""Phase 10 controlled Tally purchase posting.
+
+Revision ID: 20260822_purchase_posting_p10
+Revises: 20260822_purchase_enrich_p8
+
+Phase 9 is migration-free, so Phase 10 correctly follows the Phase 8 migration head.
+"""
+from alembic import op
+import sqlalchemy as sa
+
+revision = "20260822_purchase_posting_p10"
+down_revision = "20260822_purchase_enrich_p8"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.create_table(
+        "accounting_purchase_posting_attempts",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column("tenant_id", sa.Integer(), sa.ForeignKey("tenants.id", ondelete="CASCADE"), nullable=False),
+        sa.Column("client_id", sa.Integer(), sa.ForeignKey("clients.id", ondelete="CASCADE"), nullable=False),
+        sa.Column("purchase_id", sa.Integer(), sa.ForeignKey("accounting_gstr2b_purchases.id", ondelete="CASCADE"), nullable=False),
+        sa.Column("workstation_agent_id", sa.Integer(), sa.ForeignKey("erp_workstation_agents.id", ondelete="SET NULL"), nullable=True),
+        sa.Column("tally_guid", sa.String(120), nullable=False, server_default=""),
+        sa.Column("tally_company_name", sa.String(240), nullable=False, server_default=""),
+        sa.Column("status", sa.String(40), nullable=False, server_default="not_started"),
+        sa.Column("preflight_job_id", sa.Integer(), sa.ForeignKey("erp_agent_jobs.id", ondelete="SET NULL"), nullable=True),
+        sa.Column("posting_job_id", sa.Integer(), sa.ForeignKey("erp_agent_jobs.id", ondelete="SET NULL"), nullable=True),
+        sa.Column("preflight_result_json", sa.Text(), nullable=True),
+        sa.Column("posting_result_json", sa.Text(), nullable=True),
+        sa.Column("last_error", sa.Text(), nullable=True),
+        sa.Column("party_ledger_name", sa.String(240), nullable=False, server_default=""),
+        sa.Column("purchase_ledger_name", sa.String(240), nullable=False, server_default=""),
+        sa.Column("input_igst_ledger_name", sa.String(240), nullable=False, server_default=""),
+        sa.Column("input_cgst_ledger_name", sa.String(240), nullable=False, server_default=""),
+        sa.Column("input_sgst_ledger_name", sa.String(240), nullable=False, server_default=""),
+        sa.Column("input_cess_ledger_name", sa.String(240), nullable=False, server_default=""),
+        sa.Column("tally_voucher_id", sa.String(120), nullable=False, server_default=""),
+        sa.Column("tally_voucher_number", sa.String(160), nullable=False, server_default=""),
+        sa.Column("tally_reference", sa.String(160), nullable=False, server_default=""),
+        sa.Column("idempotency_key", sa.String(200), nullable=False, server_default=""),
+        sa.Column("requested_by_user_id", sa.Integer(), sa.ForeignKey("users.id", ondelete="SET NULL"), nullable=True),
+        sa.Column("posted_by_user_id", sa.Integer(), sa.ForeignKey("users.id", ondelete="SET NULL"), nullable=True),
+        sa.Column("created_at_utc", sa.DateTime(timezone=True), nullable=False, server_default=sa.func.now()),
+        sa.Column("updated_at_utc", sa.DateTime(timezone=True), nullable=False, server_default=sa.func.now()),
+        sa.Column("preflight_completed_at_utc", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("posting_requested_at_utc", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("posted_at_utc", sa.DateTime(timezone=True), nullable=True),
+        sa.UniqueConstraint("tenant_id", "client_id", "purchase_id", name="uq_accounting_purchase_posting_purchase"),
+    )
+    for col in (
+        "tenant_id", "client_id", "purchase_id", "workstation_agent_id", "tally_guid",
+        "status", "preflight_job_id", "posting_job_id", "idempotency_key", "created_at_utc",
+    ):
+        op.create_index(
+            f"ix_accounting_purchase_posting_attempts_{col}",
+            "accounting_purchase_posting_attempts",
+            [col],
+        )
+
+
+def downgrade():
+    op.drop_table("accounting_purchase_posting_attempts")
diff --git a/app/modules/accounting/purchase_posting_models.py b/app/modules/accounting/purchase_posting_models.py
new file mode 100644
index 0000000..b909d51
--- /dev/null
+++ b/app/modules/accounting/purchase_posting_models.py
@@ -0,0 +1,77 @@
+from __future__ import annotations
+
+from datetime import datetime, timezone
+
+from sqlalchemy import DateTime, ForeignKey, Integer, String, Text, UniqueConstraint
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.core.db.common import CommonBase
+
+
+class AccountingPurchasePostingAttempt(CommonBase):
+    """Controlled posting state for one reviewed GSTR-2B purchase.
+
+    Phase 10 intentionally keeps posting separate from the purchase review record so
+    accounting review history is never overwritten by workstation/Tally execution state.
+    """
+
+    __tablename__ = "accounting_purchase_posting_attempts"
+    __table_args__ = (
+        UniqueConstraint(
+            "tenant_id", "client_id", "purchase_id",
+            name="uq_accounting_purchase_posting_purchase",
+        ),
+    )
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+    tenant_id: Mapped[int] = mapped_column(ForeignKey("tenants.id", ondelete="CASCADE"), nullable=False, index=True)
+    client_id: Mapped[int] = mapped_column(ForeignKey("clients.id", ondelete="CASCADE"), nullable=False, index=True)
+    purchase_id: Mapped[int] = mapped_column(
+        ForeignKey("accounting_gstr2b_purchases.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+
+    workstation_agent_id: Mapped[int | None] = mapped_column(
+        ForeignKey("erp_workstation_agents.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+    tally_guid: Mapped[str] = mapped_column(String(120), nullable=False, default="", index=True)
+    tally_company_name: Mapped[str] = mapped_column(String(240), nullable=False, default="")
+
+    status: Mapped[str] = mapped_column(String(40), nullable=False, default="not_started", index=True)
+    preflight_job_id: Mapped[int | None] = mapped_column(
+        ForeignKey("erp_agent_jobs.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+    posting_job_id: Mapped[int | None] = mapped_column(
+        ForeignKey("erp_agent_jobs.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+
+    preflight_result_json: Mapped[str | None] = mapped_column(Text, nullable=True)
+    posting_result_json: Mapped[str | None] = mapped_column(Text, nullable=True)
+    last_error: Mapped[str | None] = mapped_column(Text, nullable=True)
+
+    party_ledger_name: Mapped[str] = mapped_column(String(240), nullable=False, default="")
+    purchase_ledger_name: Mapped[str] = mapped_column(String(240), nullable=False, default="")
+    input_igst_ledger_name: Mapped[str] = mapped_column(String(240), nullable=False, default="")
+    input_cgst_ledger_name: Mapped[str] = mapped_column(String(240), nullable=False, default="")
+    input_sgst_ledger_name: Mapped[str] = mapped_column(String(240), nullable=False, default="")
+    input_cess_ledger_name: Mapped[str] = mapped_column(String(240), nullable=False, default="")
+
+    tally_voucher_id: Mapped[str] = mapped_column(String(120), nullable=False, default="")
+    tally_voucher_number: Mapped[str] = mapped_column(String(160), nullable=False, default="")
+    tally_reference: Mapped[str] = mapped_column(String(160), nullable=False, default="")
+    idempotency_key: Mapped[str] = mapped_column(String(200), nullable=False, default="", index=True)
+
+    requested_by_user_id: Mapped[int | None] = mapped_column(ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
+    posted_by_user_id: Mapped[int | None] = mapped_column(ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
+
+    created_at_utc: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), nullable=False, index=True
+    )
+    updated_at_utc: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+        nullable=False,
+    )
+    preflight_completed_at_utc: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+    posting_requested_at_utc: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+    posted_at_utc: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
diff --git a/app/modules/accounting/purchase_posting_service.py b/app/modules/accounting/purchase_posting_service.py
new file mode 100644
index 0000000..9d45151
--- /dev/null
+++ b/app/modules/accounting/purchase_posting_service.py
@@ -0,0 +1,436 @@
+from __future__ import annotations
+
+import hashlib
+import json
+from datetime import datetime, timezone
+
+from sqlalchemy import select
+
+from app.modules.accounting.gstr2b_models import AccountingGSTR2BPurchase
+from app.modules.accounting.purchase_posting_models import AccountingPurchasePostingAttempt
+from app.modules.documents.agent_jobs import enqueue_agent_job
+from app.modules.documents.models import ERPAgentJob, ERPWorkstationAgent
+
+
+PREFLIGHT_ACTION = "accounting_purchase_posting_preflight"
+POST_ACTION = "accounting_post_purchase_voucher"
+TERMINAL = {"succeeded", "failed", "cancelled"}
+
+
+def _utcnow():
+    return datetime.now(timezone.utc)
+
+
+def _loads(value, default=None):
+    if not value:
+        return default if default is not None else {}
+    try:
+        parsed = json.loads(value)
+        return parsed
+    except Exception:
+        return default if default is not None else {}
+
+
+def _dumps(value):
+    return json.dumps(value, ensure_ascii=False, separators=(",", ":"), default=str)
+
+
+def _base_key(*, tenant_id: int, client_id: int, purchase: AccountingGSTR2BPurchase) -> str:
+    raw = "|".join([
+        str(tenant_id),
+        str(client_id),
+        str(purchase.id),
+        purchase.supplier_gstin or "",
+        purchase.invoice_number or "",
+        purchase.invoice_date or "",
+        purchase.document_type or "",
+    ])
+    digest = hashlib.sha256(raw.encode("utf-8", "ignore")).hexdigest()[:32]
+    return f"purchase:{client_id}:{purchase.id}:{digest}"
+
+
+def visible_workstations(db, *, tenant_id: int, branch_id: int | None = None):
+    stmt = select(ERPWorkstationAgent).where(
+        ERPWorkstationAgent.tenant_id == tenant_id,
+        ERPWorkstationAgent.is_active.is_(True),
+    )
+    if branch_id is not None:
+        stmt = stmt.where(ERPWorkstationAgent.branch_id == branch_id)
+    return list(db.execute(
+        stmt.order_by(
+            ERPWorkstationAgent.tally_connected.desc(),
+            ERPWorkstationAgent.last_seen_at_utc.desc(),
+            ERPWorkstationAgent.id.desc(),
+        )
+    ).scalars().all())
+
+
+def _purchase(db, *, tenant_id: int, client_id: int, purchase_id: int):
+    return db.execute(select(AccountingGSTR2BPurchase).where(
+        AccountingGSTR2BPurchase.id == purchase_id,
+        AccountingGSTR2BPurchase.tenant_id == tenant_id,
+        AccountingGSTR2BPurchase.client_id == client_id,
+    )).scalar_one_or_none()
+
+
+def get_attempt(db, *, tenant_id: int, client_id: int, purchase_id: int):
+    return db.execute(select(AccountingPurchasePostingAttempt).where(
+        AccountingPurchasePostingAttempt.tenant_id == tenant_id,
+        AccountingPurchasePostingAttempt.client_id == client_id,
+        AccountingPurchasePostingAttempt.purchase_id == purchase_id,
+    )).scalar_one_or_none()
+
+
+def attempts_for_purchases(db, *, tenant_id: int, client_id: int, purchase_ids):
+    ids = [int(x) for x in purchase_ids if x]
+    if not ids:
+        return {}
+    rows = list(db.execute(select(AccountingPurchasePostingAttempt).where(
+        AccountingPurchasePostingAttempt.tenant_id == tenant_id,
+        AccountingPurchasePostingAttempt.client_id == client_id,
+        AccountingPurchasePostingAttempt.purchase_id.in_(ids),
+    )).scalars().all())
+    return {r.purchase_id: r for r in rows}
+
+
+def _ensure_reviewed(purchase: AccountingGSTR2BPurchase):
+    if purchase.review_status != "reviewed":
+        raise ValueError("Only accountant-reviewed purchases may proceed to Tally posting.")
+    if not int(purchase.final_nature_id or 0):
+        raise ValueError("The purchase has no final accounting nature.")
+    if not (purchase.final_ledger_name or "").strip():
+        raise ValueError("The reviewed purchase has no mapped Tally purchase/expense ledger.")
+    if (purchase.posting_status or "").lower() == "posted":
+        raise ValueError("This purchase is already marked as posted to Tally.")
+
+
+def _accounting_relative_dir(client_id: int) -> str:
+    # This matches the existing Local Agent accounting-store binding convention.
+    return f"Accounting/clients/{int(client_id)}"
+
+
+def queue_preflight(
+    db,
+    *,
+    tenant_id: int,
+    client_id: int,
+    purchase_id: int,
+    workstation_id: int,
+    user_id: int,
+):
+    purchase = _purchase(db, tenant_id=tenant_id, client_id=client_id, purchase_id=purchase_id)
+    if not purchase:
+        raise ValueError("Purchase record was not found.")
+    _ensure_reviewed(purchase)
+
+    workstation = db.get(ERPWorkstationAgent, int(workstation_id))
+    if not workstation or not workstation.is_active or workstation.tenant_id != tenant_id:
+        raise ValueError("Selected workstation is unavailable.")
+    if not workstation.tally_connected:
+        raise ValueError("Selected workstation is not currently reporting a Tally connection.")
+
+    tally_guid = (purchase.tally_guid or "").strip()
+    if not tally_guid:
+        raise ValueError("The purchase is not associated with a mapped Tally company.")
+
+    attempt = get_attempt(
+        db, tenant_id=tenant_id, client_id=client_id, purchase_id=purchase.id
+    )
+    if not attempt:
+        attempt = AccountingPurchasePostingAttempt(
+            tenant_id=tenant_id,
+            client_id=client_id,
+            purchase_id=purchase.id,
+            tally_guid=tally_guid,
+            purchase_ledger_name=(purchase.final_ledger_name or "").strip(),
+            status="not_started",
+            requested_by_user_id=user_id,
+            idempotency_key=_base_key(
+                tenant_id=tenant_id, client_id=client_id, purchase=purchase
+            ),
+        )
+        db.add(attempt)
+        db.flush()
+
+    if attempt.status == "posted":
+        raise ValueError("This purchase has already been posted.")
+    if attempt.status in {"posting_queued", "posting_claimed", "posting_indeterminate"}:
+        raise ValueError("A posting job is already active or requires manual verification.")
+
+    attempt.workstation_agent_id = workstation.id
+    attempt.tally_guid = tally_guid
+    attempt.purchase_ledger_name = (purchase.final_ledger_name or "").strip()
+    attempt.requested_by_user_id = user_id
+    attempt.last_error = None
+
+    payload = {
+        "client_id": client_id,
+        "tenant_id": tenant_id,
+        "accounting_relative_dir": _accounting_relative_dir(client_id),
+        "tally_guid": tally_guid,
+        "supplier_gstin": purchase.supplier_gstin or "",
+        "supplier_name": purchase.supplier_name or "",
+        "invoice_number": purchase.invoice_number or "",
+        "invoice_date": purchase.invoice_date or "",
+        "invoice_value": float(purchase.invoice_value or 0),
+        "taxable_value": float(purchase.taxable_value or 0),
+        "igst": float(purchase.igst or 0),
+        "cgst": float(purchase.cgst or 0),
+        "sgst": float(purchase.sgst or 0),
+        "cess": float(purchase.cess or 0),
+        "purchase_ledger_name": attempt.purchase_ledger_name,
+        "erp_purchase_id": purchase.id,
+        "requested_by_user_id": user_id,
+    }
+
+    job = enqueue_agent_job(
+        db,
+        workstation_agent_id=workstation.id,
+        action=PREFLIGHT_ACTION,
+        payload=payload,
+        idempotency_key=f"{attempt.idempotency_key}:preflight:{workstation.id}",
+        priority=9,
+        max_attempts=2,
+        created_by_user_id=user_id,
+    )
+    attempt.preflight_job_id = job.id
+    attempt.status = "preflight_queued"
+    attempt.updated_at_utc = _utcnow()
+    db.add(attempt)
+    db.commit()
+    db.refresh(attempt)
+    return attempt
+
+
+def _job_result(job: ERPAgentJob | None):
+    if not job:
+        return {}
+    return _loads(job.result_json, {})
+
+
+def sync_attempt(db, attempt: AccountingPurchasePostingAttempt):
+    changed = False
+
+    if attempt.preflight_job_id and attempt.status.startswith("preflight"):
+        job = db.get(ERPAgentJob, attempt.preflight_job_id)
+        if job:
+            if job.status == "claimed" and attempt.status != "preflight_claimed":
+                attempt.status = "preflight_claimed"
+                changed = True
+            elif job.status == "succeeded":
+                result = _job_result(job)
+                attempt.preflight_result_json = _dumps(result)
+                attempt.tally_company_name = str(
+                    result.get("company_name")
+                    or (result.get("company") or {}).get("name")
+                    or ""
+                )[:240]
+                attempt.status = "preflight_ready"
+                attempt.preflight_completed_at_utc = job.completed_at_utc or _utcnow()
+                attempt.last_error = None
+                changed = True
+            elif job.status in {"failed", "cancelled"}:
+                attempt.status = "preflight_failed"
+                attempt.last_error = job.last_error or f"Preflight job {job.status}."
+                changed = True
+
+    if attempt.posting_job_id and attempt.status.startswith("posting"):
+        job = db.get(ERPAgentJob, attempt.posting_job_id)
+        if job:
+            if job.status == "claimed" and attempt.status != "posting_claimed":
+                attempt.status = "posting_claimed"
+                changed = True
+            elif job.status == "succeeded":
+                result = _job_result(job)
+                attempt.posting_result_json = _dumps(result)
+                tally_result = result.get("tally_result") or result
+                attempt.tally_voucher_id = str(
+                    tally_result.get("last_voucher_id")
+                    or tally_result.get("voucher_id")
+                    or ""
+                )[:120]
+                attempt.tally_voucher_number = str(
+                    tally_result.get("voucher_number")
+                    or tally_result.get("last_voucher_id")
+                    or ""
+                )[:160]
+                attempt.tally_reference = str(
+                    result.get("reference")
+                    or tally_result.get("reference")
+                    or ""
+                )[:160]
+                attempt.status = "posted"
+                attempt.posted_at_utc = job.completed_at_utc or _utcnow()
+                attempt.last_error = None
+
+                purchase = db.get(AccountingGSTR2BPurchase, attempt.purchase_id)
+                if purchase:
+                    purchase.posting_status = "posted"
+                    db.add(purchase)
+                changed = True
+            elif job.status == "failed":
+                error = job.last_error or "Tally posting failed."
+                # Phase 2 agent uses this phrase when execution began but acknowledgement
+                # was lost.  Never automatically requeue a financial write in this case.
+                if "Verify Tally before retrying" in error or "interrupted before acknowledgement" in error.lower():
+                    attempt.status = "posting_indeterminate"
+                else:
+                    attempt.status = "posting_failed"
+                attempt.last_error = error
+                changed = True
+            elif job.status == "cancelled":
+                attempt.status = "posting_failed"
+                attempt.last_error = "Posting job was cancelled."
+                changed = True
+
+    if changed:
+        attempt.updated_at_utc = _utcnow()
+        db.add(attempt)
+        db.commit()
+        db.refresh(attempt)
+    return attempt
+
+
+def sync_attempts(db, attempts):
+    return [sync_attempt(db, a) for a in attempts]
+
+
+def preflight_choices(attempt: AccountingPurchasePostingAttempt):
+    result = _loads(attempt.preflight_result_json, {})
+    return {
+        "party_candidates": result.get("party_candidates") or [],
+        "igst_candidates": result.get("igst_candidates") or [],
+        "cgst_candidates": result.get("cgst_candidates") or [],
+        "sgst_candidates": result.get("sgst_candidates") or [],
+        "cess_candidates": result.get("cess_candidates") or [],
+        "duplicate_candidates": result.get("duplicate_candidates") or [],
+        "purchase_ledger_verified": bool(result.get("purchase_ledger_verified")),
+        "company_name": result.get("company_name") or "",
+        "company_guid": result.get("company_guid") or "",
+    }
+
+
+def queue_post(
+    db,
+    *,
+    tenant_id: int,
+    client_id: int,
+    purchase_id: int,
+    party_ledger_name: str,
+    input_igst_ledger_name: str,
+    input_cgst_ledger_name: str,
+    input_sgst_ledger_name: str,
+    input_cess_ledger_name: str,
+    user_id: int,
+):
+    purchase = _purchase(db, tenant_id=tenant_id, client_id=client_id, purchase_id=purchase_id)
+    if not purchase:
+        raise ValueError("Purchase record was not found.")
+    _ensure_reviewed(purchase)
+
+    attempt = get_attempt(
+        db, tenant_id=tenant_id, client_id=client_id, purchase_id=purchase.id
+    )
+    if not attempt:
+        raise ValueError("Run workstation preflight before posting.")
+    attempt = sync_attempt(db, attempt)
+    if attempt.status != "preflight_ready":
+        raise ValueError("Successful workstation preflight is required before posting.")
+    if not attempt.workstation_agent_id:
+        raise ValueError("No workstation is attached to this posting attempt.")
+
+    choices = preflight_choices(attempt)
+    if not choices["purchase_ledger_verified"]:
+        raise ValueError("The reviewed purchase/expense ledger was not verified in the open Tally company.")
+    if choices["duplicate_candidates"]:
+        raise ValueError(
+            "A possible duplicate Purchase voucher exists in Tally. Verify it before posting."
+        )
+
+    def allowed(name, key, required):
+        value = (name or "").strip()
+        candidates = {str(x.get("name") or "").strip() for x in choices[key]}
+        if required and not value:
+            raise ValueError(f"Select {key.replace('_candidates','').upper()} ledger.")
+        if value and value not in candidates:
+            raise ValueError("Selected ledger was not returned by the current workstation preflight.")
+        return value
+
+    party = allowed(party_ledger_name, "party_candidates", True)
+    igst = allowed(input_igst_ledger_name, "igst_candidates", float(purchase.igst or 0) > 0)
+    cgst = allowed(input_cgst_ledger_name, "cgst_candidates", float(purchase.cgst or 0) > 0)
+    sgst = allowed(input_sgst_ledger_name, "sgst_candidates", float(purchase.sgst or 0) > 0)
+    cess = allowed(input_cess_ledger_name, "cess_candidates", float(purchase.cess or 0) > 0)
+
+    if not attempt.tally_company_name:
+        raise ValueError("Preflight did not return a valid Tally company name.")
+
+    reference = (purchase.invoice_number or f"ERP-{purchase.id}")[:160]
+    narration = (
+        f"Purchase imported from reviewed ERP GSTR-2B document #{purchase.id}; "
+        f"supplier GSTIN {purchase.supplier_gstin or '-'}; invoice {reference}"
+    )[:1000]
+
+    payload = {
+        "client_id": client_id,
+        "tenant_id": tenant_id,
+        "accounting_relative_dir": _accounting_relative_dir(client_id),
+        "tally_guid": attempt.tally_guid,
+        "company_name": attempt.tally_company_name,
+        "erp_purchase_id": purchase.id,
+        "invoice_number": purchase.invoice_number or "",
+        "invoice_date": purchase.invoice_date or "",
+        "supplier_gstin": purchase.supplier_gstin or "",
+        "supplier_name": purchase.supplier_name or "",
+        "party_ledger_name": party,
+        "purchase_ledger_name": attempt.purchase_ledger_name,
+        "input_igst_ledger_name": igst,
+        "input_cgst_ledger_name": cgst,
+        "input_sgst_ledger_name": sgst,
+        "input_cess_ledger_name": cess,
+        "taxable_value": round(float(purchase.taxable_value or 0), 2),
+        "igst": round(float(purchase.igst or 0), 2),
+        "cgst": round(float(purchase.cgst or 0), 2),
+        "sgst": round(float(purchase.sgst or 0), 2),
+        "cess": round(float(purchase.cess or 0), 2),
+        "invoice_value": round(float(purchase.invoice_value or 0), 2),
+        "reference": reference,
+        "narration": narration,
+        "requested_by_user_id": user_id,
+        "posting_attempt_id": attempt.id,
+    }
+
+    workstation = db.get(ERPWorkstationAgent, attempt.workstation_agent_id)
+    if not workstation or not workstation.is_active:
+        raise ValueError("Selected workstation is no longer active.")
+
+    # Deterministic key means clicking Post again returns the same durable job.
+    job = enqueue_agent_job(
+        db,
+        workstation_agent_id=workstation.id,
+        action=POST_ACTION,
+        payload=payload,
+        idempotency_key=f"{attempt.idempotency_key}:post:{workstation.id}",
+        priority=10,
+        max_attempts=1,  # Financial writes are never automatically retried.
+        created_by_user_id=user_id,
+    )
+
+    attempt.party_ledger_name = party
+    attempt.input_igst_ledger_name = igst
+    attempt.input_cgst_ledger_name = cgst
+    attempt.input_sgst_ledger_name = sgst
+    attempt.input_cess_ledger_name = cess
+    attempt.posting_job_id = job.id
+    attempt.posting_requested_at_utc = _utcnow()
+    attempt.posted_by_user_id = user_id
+    attempt.status = "posting_queued"
+    attempt.last_error = None
+    attempt.updated_at_utc = _utcnow()
+    db.add(attempt)
+
+    purchase.posting_status = "queued"
+    db.add(purchase)
+    db.commit()
+    db.refresh(attempt)
+    return attempt
diff --git a/app/modules/accounting/purchase_posting_ui.py b/app/modules/accounting/purchase_posting_ui.py
new file mode 100644
index 0000000..a2414cb
--- /dev/null
+++ b/app/modules/accounting/purchase_posting_ui.py
@@ -0,0 +1,201 @@
+from __future__ import annotations
+
+from urllib.parse import urlencode
+
+from fastapi import APIRouter, Form, Request
+from fastapi.responses import RedirectResponse
+
+from app.core.db.common import CommonSessionLocal
+from app.core.security.csrf import get_or_create_csrf_token, validate_csrf
+from app.core.templating import templates
+from app.modules.accounting.purchase_posting_service import (
+    attempts_for_purchases,
+    preflight_choices,
+    queue_post,
+    queue_preflight,
+    sync_attempts,
+    visible_workstations,
+)
+from app.modules.accounting.purchase_review_service import review_queue
+from app.modules.accounting.ui import _find_visible_client, _require_partner, _visible_clients
+from app.modules.core.rbac.deps import get_user_permissions, get_user_roles
+
+router = APIRouter(prefix="/tools/accounting/purchase-posting", tags=["accounting-purchase-posting-ui"])
+
+
+def _redirect(client_id: int, *, message: str = "", error: str = "", page: int = 1, per_page: int = 25):
+    params = {"client_id": client_id, "page": page, "per_page": per_page}
+    if message:
+        params["message"] = message[:240]
+    if error:
+        params["error"] = error[:240]
+    return RedirectResponse(
+        url="/tools/accounting/purchase-posting?" + urlencode(params),
+        status_code=303,
+    )
+
+
+@router.get("")
+def page(
+    request: Request,
+    client_id: int | None = None,
+    page: int = 1,
+    per_page: int = 25,
+    message: str = "",
+    error: str = "",
+):
+    db = CommonSessionLocal()
+    try:
+        user, response = _require_partner(request, db, "accounting.learning.view")
+        if response:
+            return response
+        clients, scope = _visible_clients(db, request, user)
+        selected = next((c for c in clients if client_id and int(c.id) == int(client_id)), None)
+
+        result = None
+        attempts = {}
+        choices = {}
+        workstations = []
+
+        if selected:
+            # Phase 10 intentionally starts only from reviewed purchases.
+            result = review_queue(
+                db,
+                tenant_id=scope.tenant_id,
+                client_id=selected.id,
+                status="reviewed",
+                page=page,
+                per_page=per_page,
+            )
+            ids = [row[0].id for row in result.rows]
+            attempts = attempts_for_purchases(
+                db, tenant_id=scope.tenant_id, client_id=selected.id, purchase_ids=ids
+            )
+            sync_attempts(db, list(attempts.values()))
+            attempts = attempts_for_purchases(
+                db, tenant_id=scope.tenant_id, client_id=selected.id, purchase_ids=ids
+            )
+            choices = {
+                pid: preflight_choices(attempt)
+                for pid, attempt in attempts.items()
+                if attempt.preflight_result_json
+            }
+
+            branch_id = getattr(user, "branch_id", None)
+            workstations = visible_workstations(
+                db, tenant_id=scope.tenant_id, branch_id=branch_id
+            )
+
+        return templates.TemplateResponse(
+            "modules/accounting/templates/accounting/purchase_posting.html",
+            {
+                "request": request,
+                "current_user": user,
+                "current_user_roles": get_user_roles(db, user.id),
+                "current_user_permissions": get_user_permissions(db, user.id),
+                "csrf_token": get_or_create_csrf_token(request),
+                "title": "Controlled Tally Purchase Posting",
+                "clients": clients,
+                "selected_client": selected,
+                "result": result,
+                "attempts": attempts,
+                "choices": choices,
+                "workstations": workstations,
+                "message": message,
+                "error": error,
+            },
+        )
+    finally:
+        db.close()
+
+
+@router.post("/purchase/{purchase_id}/preflight")
+def preflight(
+    request: Request,
+    purchase_id: int,
+    client_id: int = Form(...),
+    workstation_id: int = Form(...),
+    page: int = Form(1),
+    per_page: int = Form(25),
+    csrf_token: str = Form(...),
+):
+    validate_csrf(request, csrf_token)
+    db = CommonSessionLocal()
+    try:
+        user, response = _require_partner(request, db, "accounting.learning.manage")
+        if response:
+            return response
+        client, _, scope = _find_visible_client(db, request, user, client_id)
+        if not client:
+            from app.core.http_responses import ui_access_denied
+            return ui_access_denied()
+
+        queue_preflight(
+            db,
+            tenant_id=scope.tenant_id,
+            client_id=client.id,
+            purchase_id=purchase_id,
+            workstation_id=workstation_id,
+            user_id=user.id,
+        )
+        return _redirect(
+            client.id,
+            message="Workstation preflight queued. Refresh this page after the agent processes the job.",
+            page=page,
+            per_page=per_page,
+        )
+    except Exception as exc:
+        db.rollback()
+        return _redirect(client_id, error=str(exc), page=page, per_page=per_page)
+    finally:
+        db.close()
+
+
+@router.post("/purchase/{purchase_id}/post")
+def post(
+    request: Request,
+    purchase_id: int,
+    client_id: int = Form(...),
+    party_ledger_name: str = Form(...),
+    input_igst_ledger_name: str = Form(""),
+    input_cgst_ledger_name: str = Form(""),
+    input_sgst_ledger_name: str = Form(""),
+    input_cess_ledger_name: str = Form(""),
+    page: int = Form(1),
+    per_page: int = Form(25),
+    csrf_token: str = Form(...),
+):
+    validate_csrf(request, csrf_token)
+    db = CommonSessionLocal()
+    try:
+        user, response = _require_partner(request, db, "accounting.learning.manage")
+        if response:
+            return response
+        client, _, scope = _find_visible_client(db, request, user, client_id)
+        if not client:
+            from app.core.http_responses import ui_access_denied
+            return ui_access_denied()
+
+        queue_post(
+            db,
+            tenant_id=scope.tenant_id,
+            client_id=client.id,
+            purchase_id=purchase_id,
+            party_ledger_name=party_ledger_name,
+            input_igst_ledger_name=input_igst_ledger_name,
+            input_cgst_ledger_name=input_cgst_ledger_name,
+            input_sgst_ledger_name=input_sgst_ledger_name,
+            input_cess_ledger_name=input_cess_ledger_name,
+            user_id=user.id,
+        )
+        return _redirect(
+            client.id,
+            message="Controlled Purchase voucher job queued. Refresh to see the workstation/Tally result.",
+            page=page,
+            per_page=per_page,
+        )
+    except Exception as exc:
+        db.rollback()
+        return _redirect(client_id, error=str(exc), page=page, per_page=per_page)
+    finally:
+        db.close()
diff --git a/app/modules/accounting/templates/accounting/purchase_posting.html b/app/modules/accounting/templates/accounting/purchase_posting.html
new file mode 100644
index 0000000..fe862e5
--- /dev/null
+++ b/app/modules/accounting/templates/accounting/purchase_posting.html
@@ -0,0 +1,252 @@
+{% extends "ui/templates/base/layout.html" %}
+{% block content %}
+<div class="space-y-6">
+  <div class="flex flex-wrap items-start justify-between gap-4">
+    <div>
+      <p class="text-xs font-semibold uppercase tracking-[0.16em] text-brand-600">Tools · Accounting Intelligence</p>
+      <h1 class="mt-1 text-2xl font-semibold text-slate-900">Controlled Tally Purchase Posting</h1>
+      <p class="mt-1 max-w-4xl text-sm text-slate-500">Phase 10 posts only accountant-reviewed purchases. Every voucher must pass workstation preflight, open-company verification, Tally ledger validation, duplicate screening and a durable Phase 2 idempotent job. Financial write jobs are never automatically retried.</p>
+    </div>
+    <div class="flex flex-wrap gap-2">
+      <a href="/tools/accounting/purchase-review{% if selected_client %}?client_id={{ selected_client.id }}{% endif %}" class="rounded-xl border border-slate-300 bg-white px-4 py-2 text-sm font-semibold text-slate-700 hover:bg-slate-50">Purchase Review</a>
+      <a href="/tools/tally{% if selected_client %}?client_id={{ selected_client.id }}{% endif %}" class="rounded-xl bg-brand-600 px-4 py-2 text-sm font-semibold text-white hover:bg-brand-700">Back to Tally</a>
+    </div>
+  </div>
+
+  {% if message %}<div class="rounded-xl border border-emerald-200 bg-emerald-50 px-4 py-3 text-sm font-medium text-emerald-800">{{ message }}</div>{% endif %}
+  {% if error %}<div class="rounded-xl border border-red-200 bg-red-50 px-4 py-3 text-sm text-red-800">{{ error }}</div>{% endif %}
+
+  <div class="rounded-xl border border-amber-200 bg-amber-50 px-4 py-3 text-sm text-amber-900">
+    <strong>Controlled write boundary:</strong> Phase 10 never creates Tally ledgers or stock items. If a creditor, purchase ledger or GST input ledger cannot be verified in the currently opened Tally company, posting is blocked.
+  </div>
+
+  <section class="rounded-2xl bg-white p-5 shadow-soft">
+    <form method="get" action="/tools/accounting/purchase-posting" class="grid gap-4 md:grid-cols-4">
+      <label class="text-sm font-medium text-slate-700 md:col-span-2">
+        ERP Client
+        <select name="client_id" required class="mt-1 w-full rounded-xl border border-slate-300 bg-white px-3 py-2 text-sm">
+          <option value="">Select client</option>
+          {% for client in clients %}
+          <option value="{{ client.id }}" {% if selected_client and selected_client.id == client.id %}selected{% endif %}>{{ client.client_name }}</option>
+          {% endfor %}
+        </select>
+      </label>
+      {% if selected_client %}
+      <label class="text-sm font-medium text-slate-700">
+        Rows
+        <select name="per_page" class="mt-1 w-full rounded-xl border border-slate-300 bg-white px-3 py-2 text-sm">
+          {% for size in [10,25,50,100] %}<option value="{{ size }}" {% if result and result.per_page == size %}selected{% endif %}>{{ size }}</option>{% endfor %}
+        </select>
+      </label>
+      {% endif %}
+      <div class="flex items-end"><button class="w-full rounded-xl bg-brand-600 px-4 py-2 text-sm font-semibold text-white">Load Reviewed Purchases</button></div>
+    </form>
+  </section>
+
+  {% if selected_client and result %}
+  <section class="rounded-2xl bg-white shadow-soft">
+    <div class="flex flex-wrap items-center justify-between gap-3 border-b border-slate-200 px-5 py-4">
+      <div>
+        <h2 class="font-semibold text-slate-900">Reviewed Purchase Queue</h2>
+        <p class="mt-1 text-sm text-slate-500">{{ result.total }} reviewed purchase(s) · page {{ result.page }} of {{ result.pages }}</p>
+      </div>
+      <a href="/tools/accounting/purchase-posting?client_id={{ selected_client.id }}&page={{ result.page }}&per_page={{ result.per_page }}" class="rounded-xl border border-slate-300 bg-white px-4 py-2 text-sm font-semibold text-slate-700 hover:bg-slate-50">Refresh Job Status</a>
+    </div>
+
+    <div class="divide-y divide-slate-100">
+    {% for tuple_row in result.rows %}
+      {% set row = tuple_row[0] %}
+      {% set attempt = attempts.get(row.id) %}
+      {% set choice = choices.get(row.id) %}
+      <article class="p-5">
+        <div class="grid gap-5 xl:grid-cols-12">
+          <div class="xl:col-span-3">
+            <div class="flex flex-wrap items-center gap-2">
+              <h3 class="font-semibold text-slate-900">{{ row.supplier_name or row.supplier_gstin or 'Supplier' }}</h3>
+              {% if row.posting_status == 'posted' or (attempt and attempt.status == 'posted') %}
+              <span class="rounded-full bg-emerald-50 px-2 py-1 text-xs font-semibold text-emerald-700">Posted</span>
+              {% elif attempt %}
+              <span class="rounded-full bg-blue-50 px-2 py-1 text-xs font-semibold text-blue-700">{{ attempt.status|replace('_',' ')|title }}</span>
+              {% else %}
+              <span class="rounded-full bg-slate-100 px-2 py-1 text-xs font-semibold text-slate-600">Not started</span>
+              {% endif %}
+            </div>
+            <div class="mt-2 space-y-1 text-sm text-slate-600">
+              <div>GSTIN: <span class="font-medium text-slate-900">{{ row.supplier_gstin or '-' }}</span></div>
+              <div>Invoice: <span class="font-medium text-slate-900">{{ row.invoice_number }}</span> · {{ row.invoice_date }}</div>
+              <div>Taxable: <span class="font-medium text-slate-900">₹{{ '%.2f'|format(row.taxable_value) }}</span></div>
+              <div>Invoice Value: <span class="font-medium text-slate-900">₹{{ '%.2f'|format(row.invoice_value) }}</span></div>
+            </div>
+          </div>
+
+          <div class="xl:col-span-3">
+            <div class="rounded-xl bg-slate-50 p-3">
+              <div class="text-xs font-semibold uppercase text-slate-500">Reviewed treatment</div>
+              <div class="mt-1 font-semibold text-slate-900">{{ row.final_ledger_name }}</div>
+              <div class="mt-2 grid grid-cols-2 gap-2 text-xs text-slate-600">
+                <div>IGST ₹{{ '%.2f'|format(row.igst) }}</div>
+                <div>CGST ₹{{ '%.2f'|format(row.cgst) }}</div>
+                <div>SGST ₹{{ '%.2f'|format(row.sgst) }}</div>
+                <div>Cess ₹{{ '%.2f'|format(row.cess) }}</div>
+              </div>
+            </div>
+          </div>
+
+          <div class="xl:col-span-6">
+            {% if not attempt %}
+            <form method="post" action="/tools/accounting/purchase-posting/purchase/{{ row.id }}/preflight" class="rounded-xl border border-slate-200 p-4">
+              <input type="hidden" name="csrf_token" value="{{ csrf_token }}" />
+              <input type="hidden" name="client_id" value="{{ selected_client.id }}" />
+              <input type="hidden" name="page" value="{{ result.page }}" />
+              <input type="hidden" name="per_page" value="{{ result.per_page }}" />
+              <label class="text-sm font-medium text-slate-700">
+                Workstation running the correct open Tally company
+                <select name="workstation_id" required class="mt-1 w-full rounded-xl border border-slate-300 bg-white px-3 py-2 text-sm">
+                  <option value="">Select workstation</option>
+                  {% for ws in workstations %}
+                  <option value="{{ ws.id }}">{{ ws.machine_name }} · Agent {{ ws.agent_version or '-' }} · {{ 'Tally connected' if ws.tally_connected else 'Tally offline' }}</option>
+                  {% endfor %}
+                </select>
+              </label>
+              <button class="mt-3 rounded-xl bg-slate-900 px-4 py-2 text-sm font-semibold text-white">Run Tally Preflight</button>
+            </form>
+
+            {% elif attempt.status in ['preflight_queued','preflight_claimed'] %}
+            <div class="rounded-xl border border-blue-200 bg-blue-50 p-4 text-sm text-blue-800">
+              Preflight is waiting for workstation <strong>#{{ attempt.workstation_agent_id }}</strong>. Refresh after the Local Agent processes it.
+            </div>
+
+            {% elif attempt.status == 'preflight_failed' %}
+            <div class="rounded-xl border border-red-200 bg-red-50 p-4">
+              <div class="text-sm font-semibold text-red-800">Preflight failed</div>
+              <div class="mt-1 text-sm text-red-700">{{ attempt.last_error }}</div>
+              <form method="post" action="/tools/accounting/purchase-posting/purchase/{{ row.id }}/preflight" class="mt-3">
+                <input type="hidden" name="csrf_token" value="{{ csrf_token }}" />
+                <input type="hidden" name="client_id" value="{{ selected_client.id }}" />
+                <input type="hidden" name="page" value="{{ result.page }}" />
+                <input type="hidden" name="per_page" value="{{ result.per_page }}" />
+                <select name="workstation_id" required class="w-full rounded-lg border border-red-300 bg-white px-3 py-2 text-sm">
+                  <option value="">Select workstation</option>
+                  {% for ws in workstations %}<option value="{{ ws.id }}">{{ ws.machine_name }} · {{ 'Tally connected' if ws.tally_connected else 'Tally offline' }}</option>{% endfor %}
+                </select>
+                <button class="mt-2 rounded-lg bg-red-700 px-3 py-2 text-sm font-semibold text-white">Run New Preflight</button>
+              </form>
+            </div>
+
+            {% elif attempt.status == 'preflight_ready' and choice %}
+              {% if choice.duplicate_candidates %}
+              <div class="rounded-xl border border-red-200 bg-red-50 p-4">
+                <div class="text-sm font-semibold text-red-800">Possible duplicate found in Tally — posting blocked</div>
+                {% for dup in choice.duplicate_candidates[:5] %}
+                <div class="mt-2 text-xs text-red-700">{{ dup.voucher_number or '-' }} · {{ dup.reference or '-' }} · {{ dup.party_ledger_name or '-' }}</div>
+                {% endfor %}
+              </div>
+              {% elif not choice.purchase_ledger_verified %}
+              <div class="rounded-xl border border-red-200 bg-red-50 p-4 text-sm text-red-800">Reviewed purchase ledger <strong>{{ row.final_ledger_name }}</strong> was not found in the currently opened Tally company. Sync/fix the mapping before posting.</div>
+              {% else %}
+              <form method="post" action="/tools/accounting/purchase-posting/purchase/{{ row.id }}/post" class="rounded-xl border border-emerald-200 bg-emerald-50 p-4">
+                <input type="hidden" name="csrf_token" value="{{ csrf_token }}" />
+                <input type="hidden" name="client_id" value="{{ selected_client.id }}" />
+                <input type="hidden" name="page" value="{{ result.page }}" />
+                <input type="hidden" name="per_page" value="{{ result.per_page }}" />
+
+                <div class="text-xs font-semibold uppercase text-emerald-700">Preflight passed · {{ choice.company_name }}</div>
+                <div class="mt-3 grid gap-3 md:grid-cols-2">
+                  <label class="text-xs font-semibold text-slate-700">
+                    Creditor / Party Ledger
+                    <select name="party_ledger_name" required class="mt-1 w-full rounded-lg border border-emerald-300 bg-white px-2 py-2 text-sm">
+                      <option value="">Select party ledger</option>
+                      {% for x in choice.party_candidates %}<option value="{{ x.name }}">{{ x.name }}{% if x.gstin %} · {{ x.gstin }}{% endif %}</option>{% endfor %}
+                    </select>
+                  </label>
+
+                  {% if row.igst > 0 %}
+                  <label class="text-xs font-semibold text-slate-700">
+                    Input IGST Ledger
+                    <select name="input_igst_ledger_name" required class="mt-1 w-full rounded-lg border border-emerald-300 bg-white px-2 py-2 text-sm">
+                      <option value="">Select IGST ledger</option>
+                      {% for x in choice.igst_candidates %}<option value="{{ x.name }}">{{ x.name }}</option>{% endfor %}
+                    </select>
+                  </label>
+                  {% else %}<input type="hidden" name="input_igst_ledger_name" value="" />{% endif %}
+
+                  {% if row.cgst > 0 %}
+                  <label class="text-xs font-semibold text-slate-700">
+                    Input CGST Ledger
+                    <select name="input_cgst_ledger_name" required class="mt-1 w-full rounded-lg border border-emerald-300 bg-white px-2 py-2 text-sm">
+                      <option value="">Select CGST ledger</option>
+                      {% for x in choice.cgst_candidates %}<option value="{{ x.name }}">{{ x.name }}</option>{% endfor %}
+                    </select>
+                  </label>
+                  {% else %}<input type="hidden" name="input_cgst_ledger_name" value="" />{% endif %}
+
+                  {% if row.sgst > 0 %}
+                  <label class="text-xs font-semibold text-slate-700">
+                    Input SGST Ledger
+                    <select name="input_sgst_ledger_name" required class="mt-1 w-full rounded-lg border border-emerald-300 bg-white px-2 py-2 text-sm">
+                      <option value="">Select SGST ledger</option>
+                      {% for x in choice.sgst_candidates %}<option value="{{ x.name }}">{{ x.name }}</option>{% endfor %}
+                    </select>
+                  </label>
+                  {% else %}<input type="hidden" name="input_sgst_ledger_name" value="" />{% endif %}
+
+                  {% if row.cess > 0 %}
+                  <label class="text-xs font-semibold text-slate-700">
+                    Input Cess Ledger
+                    <select name="input_cess_ledger_name" required class="mt-1 w-full rounded-lg border border-emerald-300 bg-white px-2 py-2 text-sm">
+                      <option value="">Select Cess ledger</option>
+                      {% for x in choice.cess_candidates %}<option value="{{ x.name }}">{{ x.name }}</option>{% endfor %}
+                    </select>
+                  </label>
+                  {% else %}<input type="hidden" name="input_cess_ledger_name" value="" />{% endif %}
+                </div>
+                <button class="mt-4 rounded-xl bg-emerald-700 px-4 py-2 text-sm font-semibold text-white hover:bg-emerald-800">Post Reviewed Purchase to Tally</button>
+              </form>
+              {% endif %}
+
+            {% elif attempt.status in ['posting_queued','posting_claimed'] %}
+            <div class="rounded-xl border border-blue-200 bg-blue-50 p-4 text-sm text-blue-800">Purchase posting job is being executed by the selected workstation. Do not submit another posting job.</div>
+
+            {% elif attempt.status == 'posted' %}
+            <div class="rounded-xl border border-emerald-200 bg-emerald-50 p-4">
+              <div class="text-sm font-semibold text-emerald-800">Posted successfully to Tally</div>
+              <div class="mt-2 text-sm text-slate-700">Company: {{ attempt.tally_company_name }}</div>
+              <div class="text-sm text-slate-700">Voucher/ID: {{ attempt.tally_voucher_number or attempt.tally_voucher_id or '-' }}</div>
+              <div class="text-sm text-slate-700">Reference: {{ attempt.tally_reference or row.invoice_number }}</div>
+            </div>
+
+            {% elif attempt.status == 'posting_indeterminate' %}
+            <div class="rounded-xl border border-red-300 bg-red-50 p-4">
+              <div class="text-sm font-bold text-red-800">Manual verification required — do not retry</div>
+              <div class="mt-1 text-sm text-red-700">{{ attempt.last_error }}</div>
+              <div class="mt-2 text-xs text-red-700">The Local Agent began execution but acknowledgement was lost. Check Tally for invoice {{ row.invoice_number }} before any further action.</div>
+            </div>
+
+            {% elif attempt.status == 'posting_failed' %}
+            <div class="rounded-xl border border-red-200 bg-red-50 p-4">
+              <div class="text-sm font-semibold text-red-800">Tally posting failed</div>
+              <div class="mt-1 text-sm text-red-700">{{ attempt.last_error }}</div>
+              <div class="mt-2 text-xs text-red-700">Run a new preflight after correcting the Tally-side issue. The prior financial write job is never automatically retried.</div>
+            </div>
+            {% endif %}
+          </div>
+        </div>
+      </article>
+    {% else %}
+      <div class="p-10 text-center text-sm text-slate-500">No accountant-reviewed purchases are available for posting.</div>
+    {% endfor %}
+    </div>
+
+    {% if result.pages > 1 %}
+    <div class="flex items-center justify-between border-t border-slate-200 px-5 py-4">
+      <span class="text-sm text-slate-500">Page {{ result.page }} of {{ result.pages }}</span>
+      <div class="flex gap-2">
+        {% if result.page > 1 %}<a href="?client_id={{ selected_client.id }}&per_page={{ result.per_page }}&page={{ result.page - 1 }}" class="rounded-lg border border-slate-300 px-3 py-2 text-sm font-semibold">Previous</a>{% endif %}
+        {% if result.page < result.pages %}<a href="?client_id={{ selected_client.id }}&per_page={{ result.per_page }}&page={{ result.page + 1 }}" class="rounded-lg border border-slate-300 px-3 py-2 text-sm font-semibold">Next</a>{% endif %}
+      </div>
+    </div>
+    {% endif %}
+  </section>
+  {% endif %}
+</div>
+{% endblock %}
diff --git a/app/modules/accounting/templates/accounting/tally.html b/app/modules/accounting/templates/accounting/tally.html
index afac422..ca6d674 100644
--- a/app/modules/accounting/templates/accounting/tally.html
+++ b/app/modules/accounting/templates/accounting/tally.html
@@ -19,6 +19,7 @@
       {% if selected_client %}<a href="/tools/accounting/gstr2b?client_id={{ selected_client.id }}" class="rounded-xl border border-slate-300 bg-white px-4 py-2 text-sm font-semibold text-slate-700 hover:bg-slate-50">GSTR-2B Intelligence</a>{% endif %}
       {% if selected_client %}<a href="/tools/accounting/purchase-enrichment?client_id={{ selected_client.id }}" class="rounded-xl border border-slate-300 bg-white px-4 py-2 text-sm font-semibold text-slate-700 hover:bg-slate-50">E-Invoice / E-Way Bill</a>{% endif %}
       {% if selected_client %}<a href="/tools/accounting/purchase-review?client_id={{ selected_client.id }}" class="rounded-xl border border-slate-300 bg-white px-4 py-2 text-sm font-semibold text-slate-700 hover:bg-slate-50">Purchase Review</a>{% endif %}
+      {% if selected_client %}<a href="/tools/accounting/purchase-posting?client_id={{ selected_client.id }}" class="rounded-xl border border-slate-300 bg-white px-4 py-2 text-sm font-semibold text-slate-700 hover:bg-slate-50">Post to Tally</a>{% endif %}
       {% if selected_client %}<a href="/tools/tally/depreciation?client_id={{ selected_client.id }}" class="rounded-xl border border-slate-300 bg-white px-4 py-2 text-sm font-semibold text-slate-700 hover:bg-slate-50">Depreciation (IT)</a>{% endif %}
       <a href="/tools/tally{% if selected_client %}?client_id={{ selected_client.id }}&refresh=1{% else %}?refresh=1{% endif %}" class="rounded-xl bg-brand-600 px-4 py-2 text-sm font-semibold text-white shadow-soft hover:bg-brand-700">Refresh Tally Companies</a>
     </div>
diff --git a/app/modules/documents/agent_package.py b/app/modules/documents/agent_package.py
index d402977..8bd6260 100644
--- a/app/modules/documents/agent_package.py
+++ b/app/modules/documents/agent_package.py
@@ -4,7 +4,7 @@ import io
 from pathlib import Path
 import zipfile
 
-ERP_LOCAL_AGENT_VERSION = "1.12.0"
+ERP_LOCAL_AGENT_VERSION = "1.13.0"
 ERP_LOCAL_AGENT_NAME = "ERP Local Agent"
 RUNTIME_ROOT = Path(__file__).resolve().parent / "local_agent_runtime"
 _DETERMINISTIC_ZIP_TIMESTAMP = (2026, 1, 1, 0, 0, 0)
diff --git a/app/modules/documents/local_agent_runtime/erp_local_agent/__init__.py b/app/modules/documents/local_agent_runtime/erp_local_agent/__init__.py
index b518f6e..9a34ccc 100644
--- a/app/modules/documents/local_agent_runtime/erp_local_agent/__init__.py
+++ b/app/modules/documents/local_agent_runtime/erp_local_agent/__init__.py
@@ -1 +1 @@
-__version__ = "1.12.0"
+__version__ = "1.13.0"
diff --git a/app/modules/documents/local_agent_runtime/erp_local_agent/commands.py b/app/modules/documents/local_agent_runtime/erp_local_agent/commands.py
index 237116f..29ea135 100644
--- a/app/modules/documents/local_agent_runtime/erp_local_agent/commands.py
+++ b/app/modules/documents/local_agent_runtime/erp_local_agent/commands.py
@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from datetime import datetime, timezone
+import re
 from typing import Any
 
 from . import __version__
@@ -38,6 +39,10 @@ class AgentCommandProcessor:
                 result = self._sync_transactions(payload)
             elif action == "accounting_historical_evidence":
                 result = self._historical_evidence(payload)
+            elif action == "accounting_purchase_posting_preflight":
+                result = self._purchase_posting_preflight(payload)
+            elif action == "accounting_post_purchase_voucher":
+                result = self._post_purchase_voucher(payload)
             elif action == "accounting_depreciation_preview":
                 result = self._depreciation_preview(payload)
             elif action == "accounting_calculate_it_depreciation":
@@ -70,6 +75,8 @@ class AgentCommandProcessor:
             "tally_mapping_capability": True, "tally_master_sync_capability": True,
             "tally_transaction_sync_capability": True,
             "historical_learning_read_capability": True,
+            "purchase_posting_preflight_capability": True,
+            "purchase_voucher_write_capability": True,
             "it_depreciation_capability": True,
             "tally_writeback_capability": True,
         }
@@ -214,6 +221,154 @@ class AgentCommandProcessor:
             voucher_scope=str(payload.get("voucher_scope") or "purchase"),
         )
 
+
+    def _resolve_open_company(self, payload: dict[str, Any]) -> tuple[dict[str, Any], str]:
+        requested_guid = str(payload.get("tally_guid") or "").strip()
+        if not requested_guid:
+            raise ValueError("Mapped Tally company GUID is required.")
+        tally_status = self.tally.status()
+        if not tally_status.get("connected"):
+            raise ValueError(str(tally_status.get("error") or "TallyPrime is not connected."))
+        company = next(
+            (
+                row for row in (tally_status.get("companies") or [])
+                if str(row.get("guid") or "").strip() == requested_guid
+            ),
+            None,
+        )
+        if not company:
+            raise ValueError(
+                "The mapped Tally company is not currently open on this workstation. "
+                "Open the correct company and run preflight again."
+            )
+        company_name = str(company.get("name") or "").strip()
+        if not company_name:
+            raise ValueError("Tally returned an invalid company name.")
+        expected_name = str(payload.get("company_name") or "").strip()
+        if expected_name and expected_name.casefold() != company_name.casefold():
+            raise ValueError(
+                f"Open-company mismatch: ERP expected '{expected_name}' but Tally reports '{company_name}'."
+            )
+        return company, company_name
+
+    def _purchase_posting_preflight(self, payload: dict[str, Any]) -> dict[str, Any]:
+        client_id = int(payload.get("client_id"))
+        company, company_name = self._resolve_open_company(payload)
+        result = self.tally.purchase_posting_preflight(
+            company_name,
+            supplier_gstin=str(payload.get("supplier_gstin") or ""),
+            supplier_name=str(payload.get("supplier_name") or ""),
+            purchase_ledger_name=str(payload.get("purchase_ledger_name") or ""),
+            invoice_number=str(payload.get("invoice_number") or ""),
+            invoice_date=str(payload.get("invoice_date") or ""),
+            invoice_value=float(payload.get("invoice_value") or 0),
+        )
+        return {
+            **result,
+            "company_name": company_name,
+            "company_guid": str(company.get("guid") or ""),
+            "company_gstin": str(company.get("gstin") or ""),
+            "client_id": client_id,
+            "agent": self._agent_info(),
+        }
+
+    def _post_purchase_voucher(self, payload: dict[str, Any]) -> dict[str, Any]:
+        client_id = int(payload.get("client_id"))
+        company, company_name = self._resolve_open_company(payload)
+
+        invoice_number = str(payload.get("invoice_number") or "").strip()
+        invoice_date = str(payload.get("invoice_date") or "").strip()
+        party = str(payload.get("party_ledger_name") or "").strip()
+        purchase_ledger = str(payload.get("purchase_ledger_name") or "").strip()
+
+        rows = self.tally.purchase_posting_ledgers(company_name)
+        for label, ledger in (
+            ("creditor", party),
+            ("purchase/expense", purchase_ledger),
+            ("Input IGST", str(payload.get("input_igst_ledger_name") or "").strip()),
+            ("Input CGST", str(payload.get("input_cgst_ledger_name") or "").strip()),
+            ("Input SGST", str(payload.get("input_sgst_ledger_name") or "").strip()),
+            ("Input Cess", str(payload.get("input_cess_ledger_name") or "").strip()),
+        ):
+            if ledger and not self.tally._ledger_exists(rows, ledger):
+                raise ValueError(
+                    f"{label} ledger '{ledger}' is not present in the currently opened Tally company."
+                )
+
+        expected_gstin = re.sub(
+            r"[^A-Z0-9]", "", str(payload.get("supplier_gstin") or "").upper()
+        )[:15]
+        party_row = next(
+            (r for r in rows if str(r.get("name") or "").strip().casefold() == party.casefold()),
+            None,
+        )
+        if not party_row:
+            raise ValueError("Selected creditor ledger was not found during final validation.")
+        party_gstin = str(party_row.get("gstin") or "").strip().upper()
+        if expected_gstin and party_gstin and expected_gstin != party_gstin:
+            raise ValueError(
+                f"Supplier GSTIN mismatch: ERP has {expected_gstin}, "
+                f"but Tally ledger '{party}' reports {party_gstin}."
+            )
+
+        duplicates = self.tally.find_purchase_duplicates(
+            company_name,
+            invoice_date=invoice_date,
+            reference=invoice_number,
+            party_ledger_names=[party],
+            invoice_value=float(payload.get("invoice_value") or 0),
+        )
+        if duplicates:
+            raise ValueError(
+                "Possible duplicate Purchase voucher already exists in Tally for this "
+                "supplier/invoice/date. Posting has been blocked."
+            )
+
+        tally_result = self.tally.post_purchase_voucher(
+            company_name,
+            voucher_date=invoice_date,
+            party_ledger_name=party,
+            purchase_ledger_name=purchase_ledger,
+            taxable_value=float(payload.get("taxable_value") or 0),
+            input_igst_ledger_name=str(payload.get("input_igst_ledger_name") or "").strip(),
+            igst=float(payload.get("igst") or 0),
+            input_cgst_ledger_name=str(payload.get("input_cgst_ledger_name") or "").strip(),
+            cgst=float(payload.get("cgst") or 0),
+            input_sgst_ledger_name=str(payload.get("input_sgst_ledger_name") or "").strip(),
+            sgst=float(payload.get("sgst") or 0),
+            input_cess_ledger_name=str(payload.get("input_cess_ledger_name") or "").strip(),
+            cess=float(payload.get("cess") or 0),
+            reference=str(payload.get("reference") or invoice_number),
+            narration=str(payload.get("narration") or ""),
+        )
+
+        safe_result = {
+            k: v for k, v in tally_result.items()
+            if k not in {"raw_response", "request_xml"}
+        }
+        self.logger.info(
+            "CONTROLLED PURCHASE WRITEBACK posted client_id=%s company=%s "
+            "erp_purchase_id=%s invoice=%s party=%s tally_voucher=%s",
+            client_id,
+            company_name,
+            payload.get("erp_purchase_id"),
+            invoice_number,
+            party,
+            safe_result.get("last_voucher_id"),
+        )
+        return {
+            "posted": True,
+            "client_id": client_id,
+            "erp_purchase_id": payload.get("erp_purchase_id"),
+            "company_name": company_name,
+            "company_guid": str(company.get("guid") or ""),
+            "reference": str(payload.get("reference") or invoice_number),
+            "party_ledger_name": party,
+            "purchase_ledger_name": purchase_ledger,
+            "tally_result": safe_result,
+            "agent": self._agent_info(),
+        }
+
     def _depreciation_preview(self, payload: dict[str, Any]) -> dict[str, Any]:
         client_id = int(payload.get("client_id"))
         tally_guid = str(payload.get("tally_guid") or "").strip()
diff --git a/app/modules/documents/local_agent_runtime/erp_local_agent/tally.py b/app/modules/documents/local_agent_runtime/erp_local_agent/tally.py
index 9c7c791..0ef7fb0 100644
--- a/app/modules/documents/local_agent_runtime/erp_local_agent/tally.py
+++ b/app/modules/documents/local_agent_runtime/erp_local_agent/tally.py
@@ -439,6 +439,405 @@ class TallyLiveConnector:
             "request_xml": request_xml,
         }
 
+
+    def purchase_posting_ledgers(self, company_name: str) -> list[dict]:
+        company = str(company_name or "").strip()
+        if not company:
+            raise ValueError("Tally company name is required.")
+        xml = f"""<ENVELOPE>
+  <HEADER><VERSION>1</VERSION><TALLYREQUEST>Export</TALLYREQUEST><TYPE>Collection</TYPE><ID>ARRRPurchasePostingLedgers</ID></HEADER>
+  <BODY><DESC>
+    <STATICVARIABLES>{self._static_variables(company)}</STATICVARIABLES>
+    <TDL><TDLMESSAGE>
+      <COLLECTION NAME="ARRRPurchasePostingLedgers" ISMODIFY="No">
+        <TYPE>Ledger</TYPE>
+        <FETCH>Name,GUID,Parent,PartyGSTIN,GSTIN,GSTRegistrationNumber,TaxType,GSTApplicable,GSTRegistrationType,IsBillWiseOn</FETCH>
+      </COLLECTION>
+    </TDLMESSAGE></TDL>
+  </DESC></BODY>
+</ENVELOPE>"""
+        raw = self._post_xml(xml)
+        cleaned = _clean_xml_response(raw)
+        try:
+            root = ET.fromstring(cleaned.encode("utf-8"))
+        except Exception as exc:
+            raise ValueError(
+                f"Tally returned invalid XML while validating purchase ledgers: {exc}"
+            ) from exc
+
+        rows = []
+        seen = set()
+        for element in root.iter():
+            if _tag(element) != "LEDGER":
+                continue
+            name = (
+                element.attrib.get("NAME")
+                or element.attrib.get("name")
+                or _child_text(element, "NAME")
+            ).strip()
+            if not name or name.casefold() in seen:
+                continue
+            seen.add(name.casefold())
+            gstin = _first_text(
+                element,
+                ("PARTYGSTIN", "GSTIN", "GSTREGISTRATIONNUMBER", "GSTNO", "GSTNUMBER"),
+            )
+            rows.append({
+                "name": name,
+                "guid": _child_text(element, "GUID"),
+                "parent": _child_text(element, "PARENT"),
+                "gstin": re.sub(r"[^A-Z0-9]", "", str(gstin or "").upper())[:15],
+                "tax_type": _child_text(element, "TAXTYPE"),
+                "gst_applicable": _child_text(element, "GSTAPPLICABLE"),
+                "gst_registration_type": _child_text(element, "GSTREGISTRATIONTYPE"),
+                "is_billwise_on": _child_text(element, "ISBILLWISEON"),
+            })
+        return rows
+
+    @staticmethod
+    def _ledger_exists(rows: list[dict], name: str) -> bool:
+        key = str(name or "").strip().casefold()
+        return bool(
+            key
+            and any(
+                str(row.get("name") or "").strip().casefold() == key
+                for row in rows
+            )
+        )
+
+    @staticmethod
+    def _tax_ledger_candidates(rows: list[dict], tax: str) -> list[dict]:
+        target = str(tax or "").strip().upper()
+        patterns = {
+            "IGST": ("IGST", "INTEGRATED"),
+            "CGST": ("CGST", "CENTRAL"),
+            "SGST": ("SGST", "STATE GST", "STATE TAX", "UTGST", "UT GST"),
+            "CESS": ("CESS",),
+        }.get(target, (target,))
+        matches = []
+        for row in rows:
+            text = " ".join([
+                str(row.get("name") or ""),
+                str(row.get("parent") or ""),
+                str(row.get("tax_type") or ""),
+            ]).upper()
+            if any(pattern in text for pattern in patterns):
+                matches.append(row)
+        matches.sort(
+            key=lambda row: (
+                0
+                if any(
+                    word in str(row.get("name") or "").upper()
+                    for word in ("INPUT", "PURCHASE")
+                )
+                else 1,
+                str(row.get("name") or "").casefold(),
+            )
+        )
+        return matches[:20]
+
+    def purchase_posting_preflight(
+        self,
+        company_name: str,
+        *,
+        supplier_gstin: str,
+        supplier_name: str,
+        purchase_ledger_name: str,
+        invoice_number: str,
+        invoice_date: str,
+        invoice_value: float,
+    ) -> dict:
+        rows = self.purchase_posting_ledgers(company_name)
+        gstin = re.sub(
+            r"[^A-Z0-9]", "", str(supplier_gstin or "").upper()
+        )[:15]
+        supplier_key = re.sub(
+            r"[^A-Z0-9]", "", str(supplier_name or "").upper()
+        )
+
+        gstin_matches = [
+            row for row in rows if gstin and row.get("gstin") == gstin
+        ]
+        name_matches = []
+        if supplier_key:
+            for row in rows:
+                key = re.sub(
+                    r"[^A-Z0-9]", "", str(row.get("name") or "").upper()
+                )
+                if key == supplier_key:
+                    name_matches.append(row)
+
+        party = gstin_matches or name_matches
+        if not party and supplier_key:
+            party = [
+                row
+                for row in rows
+                if supplier_key
+                in re.sub(r"[^A-Z0-9]", "", str(row.get("name") or "").upper())
+                or re.sub(
+                    r"[^A-Z0-9]", "", str(row.get("name") or "").upper()
+                )
+                in supplier_key
+            ][:20]
+
+        duplicates = self.find_purchase_duplicates(
+            company_name,
+            invoice_date=invoice_date,
+            reference=invoice_number,
+            party_ledger_names=[
+                str(row.get("name") or "") for row in party
+            ],
+            invoice_value=invoice_value,
+        )
+
+        return {
+            "party_candidates": party[:20],
+            "purchase_ledger_verified": self._ledger_exists(
+                rows, purchase_ledger_name
+            ),
+            "igst_candidates": self._tax_ledger_candidates(rows, "IGST"),
+            "cgst_candidates": self._tax_ledger_candidates(rows, "CGST"),
+            "sgst_candidates": self._tax_ledger_candidates(rows, "SGST"),
+            "cess_candidates": self._tax_ledger_candidates(rows, "CESS"),
+            "duplicate_candidates": duplicates,
+            "ledger_count": len(rows),
+        }
+
+    def find_purchase_duplicates(
+        self,
+        company_name: str,
+        *,
+        invoice_date: str,
+        reference: str,
+        party_ledger_names: list[str] | None = None,
+        invoice_value: float = 0,
+    ) -> list[dict]:
+        target_ref = re.sub(
+            r"[^A-Z0-9]", "", str(reference or "").upper()
+        )
+        parties = {
+            str(value or "").strip().casefold()
+            for value in (party_ledger_names or [])
+            if str(value or "").strip()
+        }
+        expected = round(abs(float(invoice_value or 0)), 2)
+        if not invoice_date:
+            return []
+
+        vouchers = self.export_vouchers(
+            company_name, invoice_date, invoice_date
+        )
+        result = []
+        for voucher in vouchers:
+            if "PURCHASE" not in str(
+                voucher.get("voucher_type_name") or ""
+            ).upper():
+                continue
+            ref = re.sub(
+                r"[^A-Z0-9]",
+                "",
+                str(voucher.get("reference") or "").upper(),
+            )
+            party = str(voucher.get("party_ledger_name") or "").strip()
+            if target_ref and ref != target_ref:
+                continue
+            if parties and party.casefold() not in parties:
+                continue
+            party_amount = 0.0
+            for entry in voucher.get("ledger_entries") or []:
+                if (
+                    str(entry.get("ledger_name") or "")
+                    .strip()
+                    .casefold()
+                    == party.casefold()
+                ):
+                    party_amount = max(
+                        party_amount,
+                        abs(float(entry.get("amount") or 0)),
+                    )
+            if (
+                expected
+                and party_amount
+                and abs(party_amount - expected)
+                > max(2.0, expected * 0.005)
+            ):
+                continue
+            result.append({
+                "guid": voucher.get("guid") or "",
+                "voucher_number": voucher.get("voucher_number") or "",
+                "reference": voucher.get("reference") or "",
+                "party_ledger_name": party,
+                "date": voucher.get("date") or "",
+                "amount": party_amount,
+            })
+        return result[:20]
+
+    def build_purchase_import_xml(
+        self,
+        company_name: str,
+        *,
+        voucher_date: str,
+        party_ledger_name: str,
+        purchase_ledger_name: str,
+        taxable_value: float,
+        input_igst_ledger_name: str = "",
+        igst: float = 0,
+        input_cgst_ledger_name: str = "",
+        cgst: float = 0,
+        input_sgst_ledger_name: str = "",
+        sgst: float = 0,
+        input_cess_ledger_name: str = "",
+        cess: float = 0,
+        reference: str = "",
+        narration: str = "",
+    ) -> str:
+        company = str(company_name or "").strip()
+        party = str(party_ledger_name or "").strip()
+        purchase = str(purchase_ledger_name or "").strip()
+
+        if not company or not party or not purchase:
+            raise ValueError(
+                "Company, creditor ledger and purchase/expense ledger are required."
+            )
+
+        taxable = round(abs(float(taxable_value or 0)), 2)
+        taxes = [
+            (
+                str(input_igst_ledger_name or "").strip(),
+                round(abs(float(igst or 0)), 2),
+                "IGST",
+            ),
+            (
+                str(input_cgst_ledger_name or "").strip(),
+                round(abs(float(cgst or 0)), 2),
+                "CGST",
+            ),
+            (
+                str(input_sgst_ledger_name or "").strip(),
+                round(abs(float(sgst or 0)), 2),
+                "SGST",
+            ),
+            (
+                str(input_cess_ledger_name or "").strip(),
+                round(abs(float(cess or 0)), 2),
+                "Cess",
+            ),
+        ]
+
+        if taxable <= 0:
+            raise ValueError("Taxable value must be greater than zero.")
+        for ledger, amount, label in taxes:
+            if amount > 0 and not ledger:
+                raise ValueError(
+                    f"{label} amount exists but no input tax ledger was selected."
+                )
+
+        total = round(
+            taxable + sum(amount for _, amount, _ in taxes), 2
+        )
+        dt = _tally_date(voucher_date)
+        ref_xml = (
+            f"<REFERENCE>{self._xml_escape(reference)}</REFERENCE>"
+            if str(reference or "").strip()
+            else ""
+        )
+
+        debit_entries = [
+            f"""<ALLLEDGERENTRIES.LIST>
+        <LEDGERNAME>{self._xml_escape(purchase)}</LEDGERNAME>
+        <ISDEEMEDPOSITIVE>Yes</ISDEEMEDPOSITIVE>
+        <AMOUNT>-{taxable:.2f}</AMOUNT>
+      </ALLLEDGERENTRIES.LIST>"""
+        ]
+        for ledger, amount, _ in taxes:
+            if amount > 0:
+                debit_entries.append(
+                    f"""<ALLLEDGERENTRIES.LIST>
+        <LEDGERNAME>{self._xml_escape(ledger)}</LEDGERNAME>
+        <ISDEEMEDPOSITIVE>Yes</ISDEEMEDPOSITIVE>
+        <AMOUNT>-{amount:.2f}</AMOUNT>
+      </ALLLEDGERENTRIES.LIST>"""
+                )
+
+        return f"""<ENVELOPE>
+  <HEADER><VERSION>1</VERSION><TALLYREQUEST>Import</TALLYREQUEST><TYPE>Data</TYPE><ID>Vouchers</ID></HEADER>
+  <BODY><DESC>
+    <STATICVARIABLES><SVCURRENTCOMPANY>{self._xml_escape(company)}</SVCURRENTCOMPANY></STATICVARIABLES>
+  </DESC>
+  <DATA><TALLYMESSAGE xmlns:UDF="TallyUDF">
+    <VOUCHER VCHTYPE="Purchase" ACTION="Create" OBJVIEW="Accounting Voucher View">
+      <DATE>{dt}</DATE>
+      <VOUCHERTYPENAME>Purchase</VOUCHERTYPENAME>
+      <PERSISTEDVIEW>Accounting Voucher View</PERSISTEDVIEW>
+      <PARTYLEDGERNAME>{self._xml_escape(party)}</PARTYLEDGERNAME>
+      {ref_xml}
+      <NARRATION>{self._xml_escape(narration)}</NARRATION>
+      {''.join(debit_entries)}
+      <ALLLEDGERENTRIES.LIST>
+        <LEDGERNAME>{self._xml_escape(party)}</LEDGERNAME>
+        <ISDEEMEDPOSITIVE>No</ISDEEMEDPOSITIVE>
+        <AMOUNT>{total:.2f}</AMOUNT>
+        <BILLALLOCATIONS.LIST>
+          <NAME>{self._xml_escape(reference or 'New Ref')}</NAME>
+          <BILLTYPE>New Ref</BILLTYPE>
+          <AMOUNT>{total:.2f}</AMOUNT>
+        </BILLALLOCATIONS.LIST>
+      </ALLLEDGERENTRIES.LIST>
+    </VOUCHER>
+  </TALLYMESSAGE></DATA></BODY>
+</ENVELOPE>"""
+
+    def post_purchase_voucher(
+        self, company_name: str, **kwargs
+    ) -> dict:
+        request_xml = self.build_purchase_import_xml(
+            company_name, **kwargs
+        )
+        response_xml = self._post_xml(request_xml)
+        cleaned = _clean_xml_response(response_xml)
+
+        try:
+            root = ET.fromstring(cleaned.encode("utf-8"))
+        except Exception as exc:
+            raise ValueError(
+                f"Tally returned invalid XML after Purchase import: {exc}"
+            ) from exc
+
+        def first_int(tag_name: str) -> int:
+            text = _first_text(root, [tag_name])
+            try:
+                return int(float(str(text or "0")))
+            except Exception:
+                return 0
+
+        created = first_int("CREATED")
+        altered = first_int("ALTERED")
+        errors = first_int("ERRORS")
+        last_voucher_id = _first_text(
+            root,
+            ["LASTVCHID", "LASTMID", "LASTVOUCHERID"],
+        )
+        line_error = _first_text(root, ["LINEERROR"])
+
+        if errors > 0 or line_error:
+            raise ValueError(
+                line_error
+                or f"Tally reported {errors} error(s) while creating the Purchase voucher."
+            )
+        if created < 1 and altered < 1:
+            raise ValueError(
+                "Tally did not confirm creation of the Purchase voucher."
+            )
+
+        return {
+            "created": created,
+            "altered": altered,
+            "errors": errors,
+            "last_voucher_id": str(last_voucher_id or ""),
+            "raw_response": response_xml,
+            "request_xml": request_xml,
+        }
+
     @staticmethod
     def _parse_vouchers(xml_text: str) -> list[dict]:
         cleaned = _clean_xml_response(xml_text)
diff --git a/app/modules/documents/local_agent_runtime/erp_local_agent/tunnel.py b/app/modules/documents/local_agent_runtime/erp_local_agent/tunnel.py
index 30bbda4..172a277 100644
--- a/app/modules/documents/local_agent_runtime/erp_local_agent/tunnel.py
+++ b/app/modules/documents/local_agent_runtime/erp_local_agent/tunnel.py
@@ -190,7 +190,7 @@ class StorageAgentTunnel:
 
     def _capabilities(self) -> list[str]:
         return [
-            "storage", "local_dashboard", "manual_updates", "historical_learning_read", "accounting_act", "agent.jobs.v2",
+            "storage", "local_dashboard", "manual_updates", "historical_learning_read", "accounting_act", "agent.jobs.v2", "purchase_posting.preflight", "tally.purchase.write",
             "tally.status", "tally.company_identity", "tally.read_groups",
             "tally.read_ledgers", "tally.read_stock_items", "tally.read_vouchers",
             "tally.read_trial_balance", "tally.master_sync", "tally.transaction_sync",
diff --git a/app/ui/app.py b/app/ui/app.py
index 46bbda0..5698375 100644
--- a/app/ui/app.py
+++ b/app/ui/app.py
@@ -43,6 +43,7 @@ from app.modules.accounting.ledger_learning_ui import router as accounting_ledge
 from app.modules.accounting.gstr2b_ui import router as accounting_gstr2b_ui_router
 from app.modules.accounting.purchase_enrichment_ui import router as accounting_purchase_enrichment_ui_router
 from app.modules.accounting.purchase_review_ui import router as accounting_purchase_review_ui_router
+from app.modules.accounting.purchase_posting_ui import router as accounting_purchase_posting_ui_router
 from app.modules.registrations.ui import router as registrations_ui_router
 from app.modules.credential_vault.ui import router as credential_vault_ui_router
 from app.modules.client_identity.ui import router as client_identity_ui_router
@@ -72,6 +73,7 @@ def mount_ui(app: FastAPI) -> None:
     app.include_router(accounting_gstr2b_ui_router)
     app.include_router(accounting_purchase_enrichment_ui_router)
     app.include_router(accounting_purchase_review_ui_router)
+    app.include_router(accounting_purchase_posting_ui_router)
     app.include_router(work_tracker_ui_router)
     app.include_router(billing_ui_router)
     app.include_router(platform_billing_ui_router)