What Discover AT means
An authorization compliance chargeback. Chase classifies AT as a processing error; Solidgate groups it with authorization codes.
Common causes
- Transaction processed without a positive authorization response
- Forcing a sale after a decline
- Capturing more than the authorized amount allows
Evidence that answers it
- Positive authorization response from the issuer that the issuer can validate
- Proof of credit, if issued
How to prevent it
- Authorize every transaction and never force declined sales
- Re-authorize when the final amount exceeds tolerance
How Verdikx helps with AT
Verdikx's authorization playbook asks for the processor's approval record and keeps the response technical. You review any draft before it is submitted.
Frequently asked questions
What does Discover reason code AT mean?
Discover AT means a card transaction was not completed in line with Discover's authorization requirements: no positive authorization, a forced sale after a decline, or an amount over the allowed tolerance. Win with proof of a valid positive authorization response for the sale, or proof of credit. Chase notes the amount is limited to above the floor limit.
Is Discover AT worth fighting?
Our reference rates AT (Authorization Noncompliance) sometimes winnable, depending on the evidence you have. The evidence that answers it starts with positive authorization response from the issuer that the issuer can validate. The cardholder's bank decides the outcome.
How long does a cardholder have to file a Discover AT chargeback?
Usually 120 days from the transaction date, under the network's issuer time limits for most codes. Your processor gives you far less time to respond, so work from the due date on the case.
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Sources
- Chase Merchant Services: Chargeback Reason Codes user guide (04/2018), Discover section (checked October 5, 2026)
- Solidgate Docs: Chargeback reason codes (Discover and American Express) (checked October 5, 2026)
Last reviewed by Verdikx Research.