Reason code · American Express
Amex F24: no Card Member authorization
F24 means the Card Member denies making the charge and you didn’t show they took part. It usually follows an Amex inquiry that went unanswered or fell short. By the time F24 arrives, Amex’s guide lists only one response: a refund already processed.
What F24 means
F24 means the Card Member denies the charge and you haven’t shown they took part in it. Amex’s guide lists the situations behind it:
- A mail, phone or online charge the Card Member says they didn’t make or authorize.
- The card or card number was compromised and used by someone else.
- The card was lost, stolen or otherwise out of the Card Member’s hands.
“Card Member” is Amex’s word for the cardholder.
The fight happens at the inquiry
Read Amex’s wording closely: the Card Member denies participation and you have failed to provide proof that they took part. Checkout.com marks F24 as requiring an inquiry before the chargeback. An inquiry is Amex asking for your side before money moves.
That’s the moment that matters. Answer the inquiry fully, on time, with proof that ties this customer to this charge, and there may never be an F24.
Time limit
Amex’s guide gives Card Members up to 120 days from the transaction date for most disputes.
Your side of the clock is short. Amex’s own guide tells merchants to respond within 20 days. If you accept Amex through a processor such as Stripe or Square, the processor sets its own date, often a shorter one. The due date on your notice is the one that counts.
What proof matters at this stage
Amex’s reference guide lists one response to F24 itself: proof that a refund directly offsetting the disputed charge has already been processed. If you already refunded, show it. If you didn’t, the time to argue participation was the inquiry.
Prevention starts with your descriptor
Amex’s prevention advice for F24 starts with your billing descriptor, the name that shows on the customer’s statement. Use your “doing business as” name and location or website, add a customer service phone number, and describe the purchase clearly. A customer who recognizes the charge calls you instead of Amex.
The common mistake
Ignoring the inquiry because no money has moved yet. That silence is what turns into F24, and by then the options are thin.
Dispute Daddy builds this for you
Upload the notice and your records. Dispute Daddy builds a response around the reason Amex actually gave, and you approve it before you submit. See how the method works.
