Amex's non-receipt code, decided on proof the cardmember actually received what they paid for.
Amex's response window on C08 is 20 days from the chargeback notification, against 30 for Visa 13.1 and 45 for Mastercard 4853. A merchant on multiple networks who handles a Visa 13.1 over a comfortable 3 weeks will miss the Amex deadline on the same kind of case, so the first calendar item for any C08 is the response date.
How the dispute actually arrives
A merchant receives a C08 through Amex's dispute system, either directly via Amex's merchant portal or through a processor that aggregates Amex disputes. The notification cites the disputed transaction and the cardmember's specific claim, which often distinguishes between full non-receipt and partial non-receipt. The 20-day clock starts on the day of the notification.
Amex disputes are operationally different from Visa and Mastercard in that Amex is both the issuer and the network. There is no separate issuing bank reviewing the rebuttal. Amex's own dispute team reads the response, which means the merchant is arguing to Amex itself, not to a third-party issuer applying network rules.
What the issuer is looking for
Amex reviewing a C08 asks one question: did the merchant deliver what the cardmember paid for. The evidence is the same shape as for a Visa 13.1, with one operational difference: Amex tends to give more weight to delivery to the cardmember's verified address on file, and less to signature confirmation alone, than other networks.
Proof of delivery to the billing or shipping address is the centerpiece for physical goods. Login records, session timestamps, and usage history are the centerpiece for digital products and subscriptions. A communication trail in which the cardmember acknowledged receipt, asked a follow-up question about the product, or used it before disputing strengthens either case.
Partial-fulfilment cases need itemised shipping records. If the cardmember says they ordered five items and only received three of them, the merchant must produce records showing which items shipped and when, and ideally records showing the cardmember was informed of any back-ordered items at the time of the order.
Common scenarios merchants see
A package marked delivered that the cardmember says never reached them. The carrier tracking is the first line of defense, but Amex weighs delivery to the verified billing address heavily and gives less credit to signature-only evidence at an unverified address.
A digital product or subscription the cardmember says was never provisioned. The platform's audit log is the evidence. Account-creation timestamp, welcome-email delivery, and first-login records resolve most of these cases.
A multi-item order where only some items arrived. The itemised pick-pack-ship record is the case. Where the merchant cannot show what shipped, the dispute is usually lost on the partial portion regardless of what was delivered.
A service appointment the cardmember claims was not performed. Technician notes, GPS timestamps, and a signed completion form are the evidence. The absence of a signed completion form is the most common reason these disputes are lost.
What this code is not
Reason code C08 is not a fraud claim. If the cardmember says the transaction was not theirs, the dispute belongs under Amex F24 (no cardmember authorization). It is also not a claim about quality or fit; Amex uses separate codes (other C-series) for "not as described" disputes. Submitting fraud-style evidence on a C08, or quality evidence, misses the question Amex is asking.
Where this fits in our service
Amex reason code C08 is a code we draft rebuttal letters against where the merchant has proof of delivery or service completion. The letter is built from the cardmember's billing address, the delivery records, the digital usage data, and the relevant Amex rule citation. The shorter response window means we prioritize C08 cases when they arrive. If you are reading this because you just received one, you can start with a free first letter.
Official source: Amex rules. Last reviewed 2026-05-11.