Preserve applied, outstanding, and unapplied amounts
Three numbers may matter: the amount applied to an invoice, the invoice balance still outstanding, and any portion of the payment that remains unapplied. A clean data model stores these separately. It should not overwrite the original invoice amount or treat the source payment as if it changed.
When a customer sends a deposit before final billing, the proper accounting treatment may depend on business policy. Matching software can show candidate records, but a reviewer decides how the amount should be handled in the accounting system.
Connect later receipts to the same invoice
Several payments can settle one invoice over time. Each payment needs its own date, amount, source reference, and audit trail. The invoice then shows cumulative applications and a remaining balance until fully settled.
This history helps distinguish a legitimate installment from a duplicate import. It also gives the reviewer evidence when a customer disputes the open amount.
- Retain every source payment
- Update the remaining balance only after confirmation
- Detect repeated transaction identifiers
- Show cumulative applications in the audit trail
Do not relabel deductions as partials without review
A payment below the invoice balance could be a planned installment, a fee, a discount, a withholding, or an error. Amount alone does not determine the reason. Reference text, customer history, and remittance evidence can support a suggestion, but the difference should remain visible.
A review queue lets the user choose partial application, possible deduction, or unmatched status instead of hiding uncertainty behind one category.