Reference pagesReason codes
Inquiry
American Express R13: No reply
A American Express dispute reason code, what it asks you to prove, and what Do The Proof puts in the response.
What this code means
Inquiry answer inadequate/none
What the network says wins it
Full, timely documentation
How Do The Proof handles it
Arrives in Do The Proof as: General
How long you have to respond
- Merchant response
- 20 days from the inquiry or chargeback notice
There is no pre-arbitration. American Express is both the issuer and the network, and rules after one merchant response; it may then issue a final chargeback.
Merchants in the FR2, FR4 and FR6 programmes get no inquiry at all.
Where this comes from
- American Express, Merchant Regulations International, 17 April 2026 Read 2026-09-08.
- Stripe, reason code categories Read 2026-09-08.
Other American Express inquiry codes
Do The Proof drafts dispute responses for Shopify stores. Connect store