How decline codes work
The code comes back in the authorisation response in place of an approval. Acquirers and gateways pass it on, often mapped to their own list, next to refusals of their own that never reached the issuer.
Issuers do not always give the real reason, and generic codes are common. The code is a guide to the next step more than an explanation.
Visa's decline categories
The Visa Core Rules of 18 April 2026 require an issuer to send the code that most accurately reflects the reason, and sort the codes into four categories:
- Category 1, issuer will never approve: for example 14 (invalid account number), 41 (lost card), 43 (stolen card), 46 (closed account)
- Category 2, issuer cannot approve at this time: for example 51 (not sufficient funds), 59 (suspected fraud), 91 (issuer or switch inoperative)
- Category 3, data quality: for example 54 (expired card), N7 (CVV2 failure) and, in Europe, 1A (additional customer authentication required)
- Category 4: all other, generic codes
Why decline codes matter
Retry rules follow the category. Under the same Visa rules, a merchant must never resubmit after a category 1 decline for the same card, and may reattempt in the other categories up to 20 times in 30 days.
A gateway builds on this: no retries on dead cards, a 3-D Secure challenge after 1A, a later attempt after insufficient funds, and a clear message to the buyer.
Decline code, merchant advice code or reason code?
- Merchant advice code
- An extra value Mastercard sends with a decline, telling the merchant what to do next.
- Chargeback reason code
- Explains a dispute raised after a payment went through. A decline code explains a payment that never did.
- Payment processing error
- A technical failure before the issuer decides anything: a timeout, a bad request, a provider outage.
Where a decline code shows up in a platform
Modules that do the work
- Card acquiringCard acceptance on the phone, in store and online, through the acquirer you choose.
- CheckoutA hosted checkout for cards, wallets, bank payments and crypto, routed to the best provider.
- Analytics & monitoringProduct analytics, attribution, engagement and crash reports, on a tracking plan you control.
- Fraud & riskReal-time fraud scoring, limits and case management, with the risk engines you already trust.
Platforms that need it
Where it is written
The laws and standards this page's facts come from.
General information, not legal advice: what applies to you depends on your services and your market.