Ledger and reconciliation testing

What ledger and reconciliation testing covers

Double-entry invariants

Each rule gets automated tests over generated captures, refunds, reversals, and retries:

• Every journal balances. Debits equal credits per journal and per currency, so a journal that nets to zero only after FX conversion fails.
• Posted entries do not change. A correction posts a reversing entry, and an update or delete of a posted row through the API, an admin tool, or a migration fails.
• A balance equals the sum of its postings. A crash between the posting insert and the running balance update leaves them out of step, so tests stop the process between both writes.
• One event posts once. A retried webhook or replayed message with the same event ID produces no second journal.

Bank statement reconciliation: camt.053 and BAI2

An ISO 20022 camt.053 statement reports an opening booked balance (OPBD), booked entries, and a closing booked balance (CLBD). The SIX camt.053 guideline (version 1.0, 28 February 2022) makes OPBD with CLBD mandatory, sends only booked (BOOK) entries in camt.053, and allows pending (PDNG) entries in camt.052 and camt.054. Tests check:

• OPBD plus booked entries equals CLBD, and so does the ledger balance for that account and business date;
• a pending camt.054 entry posts neither as final nor again when camt.053 books it;
• a CRDT entry with the reversal indicator true, which that guideline defines as reversing an original debit, does not post as a new credit.

A BAI2 file wraps each account between an 03 identifier record and a 49 trailer. The 49 record carries the signed algebraic sum of all amounts in the account's records, and the 98 group and 99 file trailers sum the totals below them (Westpac BankRec BAI2 documentation). Tests send a wrong control total, a truncated 88 continuation record, and an 03 record without type code 015 (closing balance), and expect rejection of the whole file.

Real-time payment reconciliation works on intraday camt.052 and camt.054 messages, and the same booked entry arrives again in the end-of-day camt.053, so tests check the deduplication key from each bank's implementation guide. The camt.053 reconciliation guide and ISO 20022 testing requirements cover message rules.

Processor and scheme settlement files

A processor settlement file lists captures, refunds, chargebacks, and fees per batch, paid later as one net bank credit. Automated payment reconciliation matches each ledger entry to its settlement line and each payout batch to its bank credit. Injected cases: a file delivered twice under a new name, a missing fee line, a chargeback one batch after its capture, and a payout split into two bank credits. Rail file formats belong to payment rails testing.

Break classification

Test data injects one break per class, and each must get exactly one class:

• Timing difference: a transfer booked before the bank cut-off appears on the next day's statement and must clear on the next run.
• Missing in ledger: a bank fee debit has no ledger entry.
• Missing at bank: a ledger payout never reaches the statement.
• Duplicate: two ledger entries or two statement lines describe one movement.
• Amount mismatch: the reference matches and the amount differs.
• Orphan reversal: a return has no link to its original entry.

Boundary tests cover tolerances: an auto-match tolerance of 0.05 closes a one-cent loss per transaction as a match, and the drift and rounding report sums those residues per account.

FBO sub-ledgers and end-of-day balancing

In a US for-benefit-of (FBO) account programme, the sub-ledger records each end user's share. Where the bank's account records disclose the custodial relationship, pass-through deposit insurance requires each owner's interest to be ascertainable from the bank's records or from records kept in good faith and in the regular course of business by the depositor or a party keeping them for the depositor (12 CFR 330.5(b)(2)). The FDIC custodial accounts proposal (2 October 2024) would require reconciliation against beneficial ownership records no less frequently than at the close of business daily (proposed 12 CFR 375.3(b)(2) and (c)(3)(ii)). Status verified on 2026-09-16: comments closed on 16 January 2025, the Federal Register shows no final rule, and the proposal is not in force.

End-of-day tests check that the FBO statement balance equals end-user balances plus items in transit per business date, that entries after cut-off land on the next date, and that a return misallocated between two end users raises an item-level break although totals agree. The BaaS segment page lists the evidence partner banks request.

Audit trail and SOC 2 processing integrity

Criterion PI1.3 of the AICPA Trust Services Criteria states that the entity implements policies and procedures over system processing, and its 2017 points of focus include detecting and correcting production errors. Audit trail checks confirm that each correction keeps its actor, time, reason, and original entry; the SOC 2 testing requirements page lists what a service auditor samples.