A duplicate customer payment is cash already received, not a second collection from the original invoice. If the extra amount is held as a customer credit, keep that credit separate from current open invoices until the authorized QuickBooks source shows how it was applied, refunded, or otherwise resolved. The four-week forecast should never count the extra receipt again as future cash.

Intuit's duplicate-payment guidance distinguishes the extra payment, any refund or void, and the later transaction used to link the credit. Its invoice-payment documentation explains that applying a payment changes the invoice's outstanding balance. Those are different source events and should remain different forecast events.

Keep four records separate

| Record | What it proves | Forecast treatment | | --- | --- | --- | | Original invoice | The customer was billed | Use its current supported open balance | | First applied payment | The original invoice was settled in whole or part | Count the receipt once as actual cash | | Duplicate payment or credit | Additional cash or a customer credit exists | Exclude it from future collections | | Later credit application or refund | The extra amount was used or returned | Update the affected record from the observed event |

Do not reopen the first invoice merely because a second receipt exists. Do not reduce an unrelated future invoice before the source applies the credit. A net customer balance can be useful for reconciliation, but it does not replace invoice-level lineage.

Build a duplicate-payment bridge

Record the customer, original invoice identifier, first payment identifier and date, duplicate payment identifier and date, amount, deposit or settlement reference, current credit status, and owner. If the extra payment is kept for later use, add the future invoice identifier only after it exists and the source shows the application.

This creates a bridge with three totals: cash received, invoice balance settled, and unapplied customer credit. The totals may differ temporarily without implying an error in the cash forecast. The mismatch is a named reconciliation state.

If the payment is refunded, preserve both the inbound receipt and outbound refund. A refund is a new cash movement; it does not erase the fact that the duplicate receipt occurred. If the duplicate charge is voided before settlement, preserve the processor status and verify that no second cash receipt reached the bank.

Avoid premature netting

Suppose an invoice for an observed amount is paid twice and the second payment remains as a customer credit. The original invoice can be closed while the credit stays unresolved. A later invoice should enter the AR population at its issued open amount. Only after the credit is applied should the next export show the supported residual.

This rule prevents two common errors:

  • treating the duplicate payment as a forecasted receipt because it has not been allocated; and
  • subtracting the credit from a future invoice before the accounting source links the two.

Use the customer-overpayment guide for the broader overpayment boundary. Use the unapplied-cash checks when the credit cannot be tied cleanly to a source payment.

Decision rule

Count a duplicate payment once when cash is observed. Keep the resulting credit outside expected collections, preserve the original invoice state, and update a later invoice only after the authorized source records the application. If the extra amount is refunded, record the refund as its own cash event.

AR Pulse analyzes an authorized QuickBooks receivables export and separates source facts from forecast assumptions. It does not change the books, process refunds, or contact customers. View the example report to see the source-linked structure.