PowderCoatingLogix/docs/ACCOUNTING_AUDIT.md

# Accounting System Audit

> Living record of the accounting/GL audit and its remediation status.
> **Keep this file updated** whenever an accounting finding is opened or closed — the
> original audit was lost once because it was never written down. Don't let that happen again.

Last reconciled against code: **2026-06-19** (branch `dev`, commits through `9532812`).
Verification at that point: `dotnet build` clean (0 errors); `dotnet test tests/PowderCoating.UnitTests` → **290 passed, 0 failed**.

---

## How the GL is modeled (context for the findings)

Balances are computed two different ways, and they must agree:

1. **At posting time** — controllers call `AccountBalanceService.DebitAsync/CreditAsync`, which
   mutate the denormalized `Account.CurrentBalance`.
2. **At report time** — `FinancialReportService` (Trial Balance, Balance Sheet, P&L, AR/AP aging,
   statements) and `LedgerService` (per-account ledger + `RecalculateBalances`) recompute balances
   from source documents.

`LedgerService` also backs the **Balance Reconciliation report** (the detective control added in
`c2cd19e`), which compares stored `CurrentBalance` vs the ledger-recomputed balance. Any account
whose recompute path is incomplete will (a) be silently corrupted by a "Recalculate Balances" run
and (b) produce misleading output in the reconciliation report.

---

## Resolved findings (this audit batch)

| # | Finding | Fix | Commit | Verified |
|---|---------|-----|--------|----------|
| **#4** | `Sales Tax Payable` (2200) was credited on every invoice but never relieved — the liability grew forever (no remittance flow). | `JournalEntries/SalesTaxPayment` GET+POST: DR 2200 / CR bank, balanced, in a transaction, honors the period lock and validates amount + bank-account tenancy. | `0c921ba` | Posting reviewed `JournalEntriesController:235-296`. Reporting needs no change (posted JE lines already flow through TB/BS/ledger). |
| **#7** | Most report queries relied on the global tenant filter, which is **bypassed for SuperAdmin** → cross-company leakage on P&L / Balance Sheet / Trial Balance / aging / statements. | Explicit `CompanyId == companyId` predicate added to every query in `FinancialReportService`. | `9532812` | Confirmed: every query in `FinancialReportService.cs` carries an explicit `CompanyId` predicate. |
| **#9a** | A cash refund posted **DR AR** (control up) while the customer subledger went down — opposite directions → guaranteed AR drift. | Refund now **reverses the sale**: DR Sales Returns (4960) + DR Sales Tax Payable (tax portion) / CR bank; AR untouched. Split centralized in `Core/Accounting/RefundAllocation.Split`. | `2a82a1d` | Posting (`InvoicesController.IssueRefund`/`CancelRefund`) and both recompute paths (`LedgerService` §5b, `FinancialReportService` TB/BS/P&L) all use `RefundAllocation.Split` — they agree by construction. |
| **#9b** | Store-credit refunds & credit memos posted nothing to the GL on issue (only a `CreditMemo` + `Customer.CreditBalance`) → outstanding store credit invisible on the balance sheet. | New **2350 Customer Credits** liability. Issue: DR 4950 / CR 2350. Apply: DR 2350 / CR AR. Void remainder: DR 2350 / CR 4950. Updated in all 8 posting sites + TB/BS/P&L + ledger §12b. | `9ce3612` | Posting sites confirmed (`CreditMemosController` 180-185/262-270/314-320; `InvoicesController` store-credit path). Reporting `cmContraRevenue`/`cmIssuedNonVoided` math reviewed. |
| — | No detective control to catch denormalized-balance drift. | **Balance Reconciliation report** (`Reports/Reconciliation`): per-account stored vs recomputed, plus AR/AP control-vs-subledger. | `c2cd19e` | Reviewed `FinancialReportService.GetBalanceReconciliationAsync`. NOTE: its usefulness is limited by O2 below. |

### Original numbering gap
The commits reference findings **#4, #7, #9a, #9b** — implying a list of at least #1–#9. The original
audit document was never persisted and is unrecoverable. Findings **#1, #2, #3, #5, #6, #8** cannot be
matched to commits and their status is **unknown**. If the original list resurfaces, reconcile it here.

---

## Resolved findings (2026-06-19 remediation)

### O1 — Account 2300 mislabeled "Payroll Liabilities" while used as Customer Deposits — **RESOLVED**
- **Root cause refined:** there is no payroll feature posting to 2300; the deposit GL code has always used
  2300 (resolved by number) as the Customer Deposits liability. Migration `AccountingDepositsGL` already
  renamed it to "Customer Deposits" for tenants that lacked a 2300, but its `NOT EXISTS` guard **skipped**
  pre-existing tenants, leaving them mislabeled. The two seed files still created new tenants with the
  wrong name.
- **Fix (chosen approach: rename 2300, move payroll to a new 2400):**
  - Seed files now create **2300 = "Customer Deposits" (IsSystem)** and a separate **2400 = "Payroll
    Liabilities"** — `SeedDataService.Accounts.cs`, `SeedData.cs`.
  - `EnsureSystemAccountsAsync` self-heals: renames any 2300 still named "Payroll Liabilities" → "Customer
    Deposits" (preserving user renames) and ensures 2400 exists.
  - Migration `20260619233108_RenameDepositsAccountAddPayroll` does the same for existing tenants (rename
    only where Name is still the default; insert 2400 where missing). Down is best-effort (soft-deletes
    only empty 2400s; does not re-introduce the mislabel).
- Account **number 2300 is unchanged**, so the deposit posting code (`DepositsController`,
  `InvoicesController`) needed no changes — its lookups are by `"2300"`.

### O2 — `LedgerService` never recomputed 4950 Sales Discounts → recalc corrupted it — **RESOLVED**
- **Fix:** added a 4950 section to both `LedgerService.GetAccountLedgerAsync` and `ComputePriorBalanceAsync`
  that reproduces the *actual postings* so a balance recalc matches the stored balance:
  invoice discounts (DR at invoice date) + credit-memo issuance (DR full amount at issue) − the unapplied
  remainder of voided memos (CR at void). This mirrors what `AccountBalanceService` posts at
  `InvoicesController:849/1108/1629` and `CreditMemosController`, so the Balance Reconciliation report no
  longer shows false drift on 4950.
- **Note / micro-discrepancy:** the ledger uses `memo.AmountApplied` for the voided remainder (matching the
  true posting), whereas `FinancialReportService` TB/BS derive the voided portion from applications against
  non-voided invoices. These differ only in the rare case of a voided memo applied to a since-voided
  invoice. Left as-is (report-side nuance, not O2's target); documented here so it isn't mistaken for a bug.
- Regression test: `LedgerServiceTests.GetAccountLedgerAsync_SalesDiscounts4950_IncludesInvoiceDiscountsAndCreditMemoContraRevenue`.

Verification of O1+O2: `dotnet build` clean; `dotnet test tests/PowderCoating.UnitTests` → **291 passed**;
migration applied to the dev database successfully.

---

### O3 — Write-path account lookups omitted explicit `CompanyId` — **RESOLVED**
- Added `CompanyId` to every **GL posting-path** account lookup that determines where money posts:
  - `InvoicesController` — all account-resolver helpers (`GetCheckingAccountIdAsync`,
    `GetCustomerDepositsAccountIdAsync`, `GetSalesReturnsAccountIdAsync`, `GetCustomerCreditsAccountIdAsync`,
    `GetArAccountIdAsync`, `GetBadDebtAccountIdAsync`, `ResolveSalesTaxAccountIdAsync`,
    `GetSalesDiscountAccountIdAsync`, `GetGcLiabilityAccountIdAsync`) plus the bank-account and write-off
    expense dropdowns (scoped via `_tenantContext`).
  - `CreditMemosController` — Create/Apply/Void GL lookups (scoped via the in-scope `customer`/`invoice`/`memo`).
  - `GiftCertificatesController` — Create, BulkCreate, Void GL lookups + `GetGcLiabilityAccountIdAsync`.
  - `BillsController` — AP/expense account resolution that pre-fills `APAccountId` (Create + CreateFromPO).
- `DepositsController` and `JournalEntriesController.SalesTaxPayment` already scoped correctly.

### O4 — Sales-tax remittance could over-remit (drive 2200 negative) — **RESOLVED**
- `JournalEntriesController.SalesTaxPayment` (POST) now rejects any amount exceeding `taxAcct.CurrentBalance`
  (0.005 rounding tolerance), so a typo can no longer push Sales Tax Payable into an abnormal debit balance.

Verification of O3+O4: `dotnet build` clean; `dotnet test tests/PowderCoating.UnitTests` → **291 passed**.

### O5 — Gift Certificate Liability 2500 missing for new tenants / mislabeled on default company — **RESOLVED**
- **Root cause (same shape as O1):** 2500 is resolved by number as the GC liability
  (`GiftCertificatesController`). The `AccountingGapsPhase2` migration seeded it for tenants existing at
  deploy, but (a) the per-tenant seeder `SeedDataService.Accounts.cs` never created a 2500, so tenants
  onboarded afterward had **no GC liability account** and GC GL postings silently no-op'd; and (b) the
  default-company seeder `SeedData.cs` created 2500 as **"Long-Term Loan"**, so that company's GC
  obligations were mislabeled (and the migration's `NOT EXISTS` guard skipped it).
- **Fix:**
  - `SeedDataService.Accounts.cs` now seeds **2500 "Gift Certificate Liability" (IsSystem)**.
  - `SeedData.cs` now seeds 2500 as GC liability and moves the long-term loan to **2900**.
  - `EnsureSystemAccountsAsync` self-heals: renames any 2500 still named "Long-Term Loan" → "Gift
    Certificate Liability" (preserving user renames) and ensures a 2500 exists.
  - Migration `20260620002950_FixGiftCertificateLiabilityAccount`: moves long-term loan to 2900 where a
    2500="Long-Term Loan" exists and no 2900 is present; relabels the mislabeled 2500; safety-net inserts a
    2500 for any company lacking one. Non-destructive (no Id/number/balance changes); Down is best-effort.
- Verified on the dev DB: existing 2500 GC-liability rows preserved; no spurious accounts added; build
  clean; migration applied; **291 unit tests pass**.

---

## Read-path account lookup sweep (Tier 1–3) — **RESOLVED**
Completed the app-wide defense-in-depth pass: every `Accounts` lookup in a controller now carries an
explicit `CompanyId` predicate, matching the standing rule in CLAUDE.md. ~19 lookups across 12 controllers:
- **Tier 1 (write-path validation):** `AccountsController` duplicate account-number check on Create/Edit.
- **Tier 2 (dropdowns/lists):** `AccountsController` (Index/year-end/parent dropdown), `BankReconciliations`,
  `Bills` (bank list + receipt-scan + suggest), `Budgets`, `CatalogItems`, `Expenses`, `FixedAssets`,
  `Inventory`, `JournalEntries` (chart dropdown), `Vendors`.
- **Tier 3 (`accountIds.Contains` display maps):** `JournalEntries` Details, `Reports` budget vs actual,
  `VendorCredits` Details — scoped via the in-scope entity's `CompanyId` for uniformity.
`companyId` source per controller: `_tenantContext.GetCurrentCompanyId()` where available, else the
in-scope entity's `CompanyId`, else `_userManager` current user. Build clean; 291 unit tests pass.

## Status
All audit findings **O1–O4 are resolved** on `dev`. Original audit numbering #1–3/#5/#6/#8 remains
unrecoverable (see top). The accounting batch has **not** been merged to `master`/production yet.