Mastercard's amount-differs code, decided on the authorization record and any post-checkout tip or currency adjustments.
Mastercard 4831 turns on what the cardholder consented to, in writing or by electronic agreement, at the time of the original transaction. Where the merchant has a signed receipt, a click-through consent, or a disclosed final-amount agreement, the case is defensible. Where the merchant adjusted the amount after the buyer agreed to something else without a corresponding consent record, the chargeback usually succeeds.
How the dispute actually arrives
A 4831 typically arrives within a billing cycle or two of the disputed transaction. The notification cites the disputed amount, the amount the cardholder claims to have authorized, and the gap between them. The merchant has 45 days to respond, the same window as other Mastercard consumer disputes.
Hospitality and rental businesses see the bulk of 4831 disputes. Restaurants generate 4831s on tip adjustments where the signed receipt and the settled amount diverge. Hotels and rental companies generate them on final-amount settlements that differ from the initial authorization. Currency-conversion 4831s land disproportionately on merchants who sell across borders without explicit conversion disclosure.
What the issuer is looking for
Issuers reviewing a 4831 ask one question: what amount did the cardholder agree to, and does the settled amount match that agreement.
The signed receipt or electronic agreement is the foundation. For a card-present transaction with a signature, the receipt with the cardholder's signature and the total written or printed on it is the case. For a card-not-present transaction, the click-through consent at checkout, with the total displayed at the moment of consent, is the equivalent. Where the consent record shows an amount and the settled transaction matches it, the dispute fails on the merits.
Tip and service-charge adjustments are the most common 4831 territory. Mastercard rules permit merchants to add a tip after the cardholder departs in defined hospitality categories, with the tip amount entered into the settled transaction by the merchant. The defense is the original signed receipt showing the base amount and a tip line, plus the settled transaction showing the base-plus-tip total. Where the merchant added a tip to a receipt that did not have a tip line, or settled an amount the cardholder did not anticipate, the dispute is harder.
Currency-conversion disputes require the conversion rate as disclosed to the buyer at the point of sale, plus the buyer's consent to be charged in the merchant's currency rather than their own. Mastercard's Dynamic Currency Conversion rules require the merchant to disclose the conversion rate before the buyer accepts. A merchant who can produce the disclosure and the consent has a defensible case; a merchant who applied the conversion without disclosure does not.
Common scenarios merchants see
A restaurant charge where a tip was added after the cardholder signed for the base amount. The defense is the receipt with the tip line and the cardholder's signature on the total or on the gratuity field.
A transposed digit. Where the merchant entered the wrong amount at the point of sale and the cardholder is disputing the difference, the right move is to refund the difference and accept the chargeback on the rest. Fighting a real error damages the chargeback ratio for no recovery.
A currency-conversion dispute. The defense is the disclosure shown to the buyer at the point of sale, the conversion rate used, and the buyer's consent to be charged in the merchant's currency. Without that disclosure, the dispute is usually lost.
An estimated charge that settled at a different final amount. The defense is the original authorization, the cardholder's consent to a variable final charge, and the records (rental damage assessment, hotel folio, etc.) that justify the difference between the estimate and the settlement.
What this code is not
Reason code 4831 is not a fraud claim. If the cardholder says they did not authorize any charge, the dispute belongs under Mastercard 4837 (no cardholder authorization). It is also not a quality claim or a non-receipt claim. If the buyer received goods or services they object to on other grounds, the dispute belongs under Mastercard 4853 (cardholder dispute) with the relevant condition cited.
Where this fits in our service
Mastercard reason code 4831 is a code we draft rebuttal letters against where the merchant has the signed receipt, the electronic consent, or the disclosed-final-amount agreement that supports the settled charge. The letter cites the consent record, the relevant Mastercard rule provision, and the records that link the settled amount to what the cardholder agreed to. If you are reading this because you just received one, you can start with a free first letter.
Official source: Mastercard rules. Last reviewed 2026-05-11.