# Phase 4.5 Verification Gate — Credit Note & Customer Adjustments

**Phase:** 4.5 Credit Note & Customer Adjustments  
**Verification Date:** September 4, 2026  
**Status:** PASSED & APPROVED  

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## Verification Criteria & Checklist

| Criteria | Result | Evidence / Implementation Details |
|---|---|---|
| **1. CreditNote Engine Complete** | PASS | `CreditNoteService::applyCreditNoteToInvoice()` implemented. |
| **2. CreditNote Draft Creation** | PASS | `createDraft()` verified with reason and customer link. |
| **3. Line & Total Recalculation** | PASS | `addLine()`, `removeLine()`, and `recalculateCreditNoteTotals()` compute subtotals and tax safely. |
| **4. Issuance State Machine** | PASS | `issueCreditNote()` verifies non-empty lines and sets status to `ISSUED`. |
| **5. Credit Note Application** | PASS | Applies credit note against customer invoice balance in an atomic transaction (`DB::transaction`). |
| **6. Pessimistic Row Locking** | PASS | `lockForUpdate()` executed on CreditNote and Invoice rows. |
| **7. Over-Application Prevention** | PASS | Rejects amounts exceeding `remaining_credit` or `balance_due`. |
| **8. Customer Alignment Guard** | PASS | Rejects application if Credit Note customer != Invoice customer. |
| **9. Tenant Security & Isolation** | PASS | Enforces `organization_id` & `business_unit_id` equality (`CrossOrganizationException`). |
| **10. Business-Unit Security** | PASS | Scoped via `BusinessUnitScope` and server-side domain checks. |
| **11. Concurrency Safety** | PASS | Race conditions prevented via SQL row locking inside database transactions. |
| **12. Zero GL Posting Introduced** | PASS | Accounting boundary preserved; GL postings strictly deferred to Phase 4.7. |
| **13. Code Formatting (Laravel Pint)** | PASS | `vendor/bin/pint --format agent` passed clean (`{"tool":"pint","result":"passed"}`). |
| **14. Full Suite Test Regression** | PASS | 218 / 218 tests passed, 397 assertions, 0 failures, 0 errors, 0 skipped. |

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## Verification Conclusion

Phase 4.5 is **PASSED & APPROVED**.

```text
PHASE 4.5 STATUS: COMPLETE.
HARD STOP. PHASE 4.6 NOT STARTED.
AWAITING HUMAN AUTHORIZATION.
```