Reference pagesReason codes
Miscellaneous
American Express M01: Chargeback Authorization
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
Merchant-authorized chargeback / rental loss
The inventory records this row as coming from Stripe's map rather than from Amex's own Regulations, whose whole April 2026 document does not list this code. One other published list still prints it. The inventory marks the pairing uncertain.
What the network says wins it
agreement
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
- Stripe, reason code categories Accessed 8 September 2026.
Other American Express miscellaneous codes
Do The Proof drafts dispute responses for Shopify stores.
You pay when a dispute is won. Not before.