What Mastercard 4812 means
The transaction was posted to an account number the issuer does not recognize. In the current guide, a transaction on a non-existent primary account number is an authorization-related chargeback under 4808.
Common causes
- Keyed entry errors without an authorization
- Offline transactions that never checked the card number
- Stored card data corrupted in migration
Evidence that answers it
- Processor authorization record showing the number was approved
- Receipt showing the same account number as the chargeback
How to prevent it
- Authorize every transaction online
- Use tokenized card storage rather than raw numbers
Time limits and caveats
Legacy code. The Chargeback Guide (13 May 2025) says issuers may still cite 4807 or 4812, but they will eventually be eliminated; the dispute is processed under the 4808 rules and time frames.
How Verdikx helps with 4812
Verdikx recognizes 4812 on older notices and maps it to its authorization playbook, the same one used for 4808: the only useful evidence is an approved authorization from your processor, and without one accepting is the sensible call.
Frequently asked questions
What does Mastercard reason code 4812 mean?
Mastercard 4812 Account Number Not on File is a legacy code. Mastercard's Chargeback Guide lets issuers still use it, but it says the code will eventually be eliminated, and the claim belongs to 4808 Authorization-Related Chargeback. It means the card number did not exist on the issuer's file, so it is rarely defensible.
Is Mastercard 4812 worth fighting?
Our reference rates 4812 (Account Number Not on File (legacy)) usually one to accept: a response rarely changes the outcome. The evidence that answers it starts with processor authorization record showing the number was approved. The cardholder's bank decides the outcome.
How long does a cardholder have to file a Mastercard 4812 chargeback?
Usually 90 days from the transaction date, under the network's issuer time limits. Your processor gives you far less time to respond, so work from the due date on the case.
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Sources
- Mastercard Chargeback Guide, Merchant Edition (13 May 2025) (checked October 5, 2026)
- Rapyd Acquiring Dispute Operation Guide: Mastercard (legacy code consolidation) (checked October 5, 2026)
Last reviewed by Verdikx Research.