Reference pagesReason codes
Authorization
American Express A02: No valid authorisation
An American Express dispute reason code, what it asks you to prove, and what Do The Proof puts in the response.
What this code means
Declined/expired/no auth
What the network says wins it
valid Authorisation Approval was obtained
or credit already processed
- Authorization and processing records
How the app handles it
Arrives in the app as: General
How long you have to respond
- Merchant response
- 20 days from the inquiry or chargeback notice
Where this comes from
- American Express, Merchant Regulations International, 17 April 2026
- Stripe, reason code categories Accessed 8 September 2026.
Other American Express authorization codes
Do The Proof drafts dispute responses for Shopify stores.
You pay when a dispute is won. Not before.