# Phase 4.2 Verification Gate

**Document Status:** PASSED & VERIFIED  
**Phase:** 4.2 Commercial Document Lifecycle & Payment Allocation  
**Date:** September 4, 2026  

---

## Gate Summary

Phase 4.2 has satisfied all technical, domain lifecycle, security, transactional locking, and accounting boundary criteria.

### Verification Checklist
- [x] **Pre-Implementation Assessment:** Formulated and validated against codebase.
- [x] **Domain Services:** Created `InvoiceService`, `SupplierInvoiceService`, `CreditNoteService`, `PaymentAllocationService` under `app/Domains/Core/Services/`.
- [x] **Lifecycle State Machines:** Enforced status transitions (`DRAFT` → `ISSUED` → `CANCELLED`/`VOIDED`/`PAID`, `DRAFT` → `RECEIVED` → `APPROVED` → `VOIDED`/`PAID`, `DRAFT` → `ISSUED` → `VOIDED`).
- [x] **Invalid State Protections:** `InvalidStateTransitionException` thrown for invalid transitions.
- [x] **Transactional Locking:** Pessimistic locking (`lockForUpdate`) applied during invoice issuance, bill approval, and payment allocation transactions.
- [x] **Payment Allocation Rules:** Allocation amount checked against `$payment->unallocated_amount` and `$document->balance_due`. Allocation to `DRAFT`, `CANCELLED`, or `VOIDED` documents rejected with `AllocationException`.
- [x] **Tenant Scopes:** Multi-tenant boundaries (`OrganizationScope` and `BusinessUnitScope`) enforced across all operations; cross-tenant allocations rejected with `CrossOrganizationException`.
- [x] **Money Rules:** High-precision string calculations (`Decimal(15,4)`) using `bcadd`, `bcsub`, `bcmul`.
- [x] **Accounting Boundary:** Zero GL journal postings (`FinancialService::postJournal()`) performed during Phase 4.2.
- [x] **Code Formatting:** Laravel Pint (`vendor/bin/pint --format agent`) passed cleanly.
- [x] **Test Baseline:** 187 / 187 tests passed (324 assertions, 0 failures, 0 errors).

---

## Sign-Off

Phase 4.2 Commercial Document Lifecycle & Payment Allocation is formally APPROVED.