Ledger Posting & Account Integrity Policy¶


Code	`PAY-007`
Domain	Payments & Settlement
Owner	Chief Financial Officer
Status	Draft
Applicability	Platform
Jurisdiction	NZ + AU
Business domain	BD02
Review date	2027-03-31

Purpose¶

Establish the core banking ledger and account model as controlled policy objects. Governs posting rules, balance states, account lifecycle controls, suspense routing, and the source-of-truth treatment of the banking ledger.

This is an internal architecture obligation derived from the live platform design, the BD02 Finance ledger boundary, and the posting engine architecture in SD01.

Scope¶

All financial value movements processed by the platform regardless of channel, product, or jurisdiction.

Policy statements¶

All banking financial value movements SHALL be represented in a real-time double-entry ledger where each posting set balances to zero.

All posting rules SHALL be centrally defined, version-controlled, and executed only by the authorised posting engine. Direct writes to the banking ledger are prohibited.

Account balances SHALL be derived from ledger events. The platform MAY maintain cache or summary views, but such views are not the source of truth and SHALL be rebuildable from ledger history.

The platform SHALL distinguish at minimum current balance, available balance, and pending hold effects for relevant account types.

Every customer account SHALL operate through a governed state model. Restricted, frozen, closed, dormant, or otherwise non-transactable accounts SHALL be blocked from disallowed transactions.

Account closure SHALL require zero posted balance, no unresolved pending holds, no unresolved suspense items, and retention of historical account records per the applicable retention schedule.

Corrections to historical financial events SHALL be made through linked reversal or compensating entries, never through mutation or deletion of posted records.

Where a posting cannot be completed safely, the event SHALL fail closed or route to a controlled suspense or exception state with durable traceability.

Multi-currency postings SHALL record each currency leg and the affected internal or nostro positions in a way that preserves full auditability.

Satisfying modules¶

Module	Name	Mode	Description
MOD-001	Double-entry posting engine	`LOG`	Every payment posting is recorded in the immutable ledger — provides the transaction record required for payment obligations and dispute resolution.
MOD-002	Immutable transaction log	`LOG`	Immutable transaction log provides the authoritative record of all payment events — cannot be altered or suppressed after posting.

Part of Payments & Settlement · Governance overview Compiled 2026-05-22 from source/entities/policies/PAY-007.yaml