If Amex reverses the credit, do I still need to charge the customer?

The reversal only recovers the mistaken credit. The original purchase remains uncollected, so process the sale properly, ideally after telling the customer what happened.

What if the credit was a real refund the customer deserved?

Respond to the case with the return or cancellation documentation. A deliberate, justified refund is not a processing error, and the evidence should stop the reversal.

American Express · Processing Errors

Reason code P04: Charge Processed as Credit

P04 is the mirror image of P03: a transaction that should have debited the cardmember was submitted as a credit, so the merchant paid the customer instead of collecting from them. Amex uses this code to unwind the erroneous credit and restore the correct flow of funds.

Issuer filing window

typically 120 days from the processing error

Merchant response window

typically 20 days to respond

Why P04 chargebacks happen

Refund mode was left active on a terminal and a sale went out as a credit.
An integration mapped the transaction type incorrectly for certain order flows.
A manual adjustment meant to collect a balance was entered with the wrong sign.
Duplicate correction attempts crossed, leaving a stray credit on the account.

How to fight a P04 chargeback

Confirm from your settlement records that a credit was issued where a charge belonged, then cooperate with the reversal since it restores money to you.
If the credit was actually a legitimate refund the customer was owed, respond with the return or cancellation record proving it was intentional.
After the reversal, process the original sale correctly with the customer's knowledge so the purchase is finally collected.
Audit surrounding transactions from the same operator or batch, since sign errors rarely happen once.

How to prevent P04 chargebacks

Separate sale and refund workflows visually and procedurally on every POS and virtual terminal.
Alert on credits that lack a matching original sale, return record, or RMA.
Add automated tests to payment integrations asserting transaction type per flow.
Reconcile net settlement daily so an unexpected outflow surfaces within a day, not a statement cycle.

Frequently asked questions

If Amex reverses the credit, do I still need to charge the customer?: The reversal only recovers the mistaken credit. The original purchase remains uncollected, so process the sale properly, ideally after telling the customer what happened.
What if the credit was a real refund the customer deserved?: Respond to the case with the return or cancellation documentation. A deliberate, justified refund is not a processing error, and the evidence should stop the reversal.

Related American Express codes