Mastercard reason code 4831: what it means and how to respond
Mastercard reason code 4831 covers a charge that differs from the agreed amount. See when it applies, what evidence to gather, and the deadlines.
What Mastercard reason code 4831 means and when it applies
Mastercard reason code 4831, “Transaction Amount Differs,” describes a charge whose amount differs from what the cardholder agreed with the merchant. The issuer files the dispute after the cardholder reports the error. Mastercard allows the issuer to dispute only the difference between the correct amount and the amount charged, not the full transaction amount.
For a dispute to qualify under 4831, all of these requirements must be present:
- The cardholder says the amount is wrong. The cardholder tells the issuer what should have been charged and what amount appeared in the transaction.
- The agreed amount can be documented. 4831 is not available when the price was agreed only verbally.
- The transaction did not take place at an ATM. Mastercard excludes ATM transactions from this condition.
- The issuer disputes only the difference. If the correct amount was $100 and the charge was $120, the chargeback may cover $20, not $120.
Source for the requirements: Mastercard Chargeback Guide, Merchant Edition dated May 19, 2026, “Transaction Amount Differs,” pp. 702–704.
4831 is a legacy code in the Dual Message SystemThis is Mastercard’s processing environment in which code 4831 may be used. For the same condition, Mastercard recommends code 4834.. Mastercard still accepts it, but states that it will be eliminated and recommends using 4834. This does not leave 4831 without a defined process: when a dispute arrives under this code, it follows the Chargeback Guide’s “Transaction Amount Differs” section.
Source for the code’s status and the recommended code: Mastercard Chargeback Guide, “Transaction Amount Differs,” p. 704.
If the problem is not the amount, check the reason shown in the dispute notice. 4834 covers other point-of-interaction errors, including duplicate charges, currency errors, and cash not dispensed by an ATM.
Deadlines for each party under Mastercard 4831
1 block represents 5 calendar days.
- IssuerFile the 4831 chargebackThe clock starts when Mastercard processes the transaction.Up to 90 calendar days
- IssuerSubmit chargeback documentation through MastercomThe clock starts when the chargeback is generated.Up to 8 calendar days
- AcquirerSubmit the second presentmentThe clock starts when Mastercard processes the chargeback.Up to 45 calendar days
- AcquirerSubmit second-presentment documentation through MastercomThe clock starts when the second presentment is generated.Up to 8 calendar days
- IssuerFile pre-arbitrationThe clock starts when Mastercard processes the acquirer’s second presentment.Up to 30 calendar days
- AcquirerRespond to pre-arbitrationThe clock starts when the pre-arbitration case is marked as submitted in Mastercom.Up to 30 calendar days
- IssuerFile for Mastercard arbitrationThe clock starts when the pre-arbitration case is marked as rejected in Mastercom.Up to 15 calendar days
Who files the dispute and what happens next
The issuer files 4831 after the cardholder says the wrong amount was charged. Under the general rule, the issuer includes a letter, email, cardholder message, or Form 1240This is Mastercard’s standard form for recording a point-of-interaction error claim. For this code, it states the amount the cardholder says should have been charged.. The document must explain the claim and state the correct amount. A receipt, invoice, final hotel or rental bill, or an email from the merchant confirming the price may complete the evidence.
Some domestic markets impose additional supporting-document requirements for gratuity disputes. That exception is regional and does not change the general rule for US or international transactions.
Source for the issuer’s documents and the market-specific gratuity rule: Mastercard Chargeback Guide, “Transaction Amount Differs,” pp. 702–703.
When the issuer files the chargeback, it returns the disputed difference to the acquirer. The merchant gathers the documents and gives them to the acquirer, which sends the formal response as a second presentmentThis is the acquirer’s formal response to the chargeback. It presents the merchant’s ground and documents to return financial responsibility to the issuer. through MastercomThis is Mastercard’s system where issuers and acquirers submit disputes, responses, and case documents..
If the issuer maintains the dispute, it must file pre-arbitrationAt this stage, the issuer responds to the second presentment and requests another review before taking the case to Mastercard for a decision.. Because 4831 does not apply to ATM transactions and is a Dual Message System code, this stage is required before arbitration.
Source for the dispute flow: Mastercard Chargeback Guide, “Transaction Amount Differs,” pp. 704–712, and “Issuer Submission of a Pre-arbitration Case,” pp. 781–787.
Before building a defense, check whether this dispute is invalidProving any one condition is enough to challenge the dispute's validity.
- The price was agreed only verbally; Mastercard does not make this chargeback condition available for verbal agreements.
- The transaction took place at an ATM; Transaction Amount Differs is not available for ATM transactions.
- The issuer disputed the full transaction amount rather than only the difference between the correct amount and the amount charged.
- The merchant’s documents show that the cardholder agreed to the full amount actually charged.
- The merchant already refunded the difference, and the acquirer documented that refund in the second presentment.
- The dispute does not meet the condition’s requirements, was filed outside the deadline, or was processed more than once.
Source:Mastercard Chargeback Guide (Merchant Edition, 19 mai. 2026), Transaction Amount Differs, pp. 702–712
How to reduce the risk of this reason code
The guide does not have a separate prevention section for 4831. The practices below follow from the documents that determine whether the amount charged was correct:
- Record the final amount before completing the charge. Keep the receipt, order, invoice, or another document showing the exact amount the customer accepted.
- Obtain verifiable agreement. A signed receipt or another recorded acceptance shows the agreed amount. Do not leave the price documented only in a verbal conversation.
- For hotels or rental businesses, keep the final bill. It records the final amount when the charge differs from the initial estimate.
- If an error occurred, refund exactly the difference. Keep the amount, date, and reference for the credit, and confirm that the refund is linked to the original transaction.
- Prepare the documents before the acquirer’s deadline. The merchant’s internal response window may be shorter than Mastercard’s 45-day period.
Source for the documents supporting the correct amount or the refund: Mastercard Chargeback Guide, “Transaction Amount Differs,” pp. 703–709.
Evidence the merchant needs to gather
There are two substantive, mutually exclusive defense paths. Exactly one must match what happened:
- The full amount was correct. Provide the merchant’s explanation and the document showing that the cardholder agreed to that amount, such as a signed receipt, invoice, or final hotel or rental bill. The acquirer uses response code 2700, “Correct amount billed.”
- The difference was already refunded. Provide proof linking the credit to the original transaction and showing the amount and date. If the refund was issued before the second presentment, the acquirer uses code 2011, “Credit Previously Issued.” To resolve the entire discrepancy, the refund must cover the full difference; if it was partial, the issuer may continue the dispute for the remaining balance.
Do not combine the two paths as if they were cumulative requirements. The first states that the amount was not wrong. The second acknowledges the difference and shows that it was corrected.
Source for the two defense paths: Mastercard Chargeback Guide, “Correct amount billed” and “Refund previously issued,” pp. 705–709.
Separate procedural grounds also apply. The acquirer may respond when the cardholder’s documents appear altered or falsified, when the chargeback does not meet the requirements, when it was filed outside the deadline, or when it was processed more than once. The acquirer may also identify required documentation that is missing, illegible, incomplete, or belongs to another case. A PAN difference between the document and the processing record, by itself, is not enough; Mastercard prohibits using that discrepancy alone as the ground for a second presentment.
The issuer’s general deadline to file 4831 is 90 calendar days from the transaction’s Central Site Business DateThis is the date Mastercard records in PDS 0158, subfield 5. It counts as day zero when calculating this dispute’s deadline.. The acquirer has 45 calendar days from the chargeback date to submit the second presentment. Documentation must reach Mastercom within 8 calendar days after the response is generated; Mastercard will not consider it if it arrives after pre-arbitration or arbitration has already been filed.
Source for the procedural grounds and deadlines: Mastercard Chargeback Guide, “Transaction Amount Differs,” pp. 703–712, and “Supporting Documentation,” pp. 688–689.
Frequently asked questions
When does Mastercard use chargeback code 4831?
The issuer may use 4831 when the cardholder says the amount charged differs from the amount agreed with the merchant. The code allows only the difference between those amounts to be disputed. It does not apply to a price agreed only verbally or to an ATM transaction.
Can a Mastercard 4831 chargeback include the full transaction amount?
No. Mastercard allows a chargeback only for the difference between the correct amount and the amount charged. If the issuer included the undisputed portion, the acquirer may respond for the amount above that difference.
How can a merchant respond to reason code 4831?
There are two substantive paths, and exactly one must match the case: provide documents showing that the cardholder agreed to the full amount charged, or prove that the difference has already been refunded. A verbal agreement alone does not support the first path.
Is Mastercard reason code 4831 still active?
Mastercard still accepts 4831 in the Dual Message System, but recommends code 4834 and states that 4831 will be eliminated. The applicable rule remains the Transaction Amount Differs section of the Chargeback Guide.
What is the deadline for a Mastercard 4831 chargeback?
Under the general rule, the issuer has 90 calendar days from the transaction’s Central Site Business Date, counted as day zero. The acquirer has 45 calendar days from the chargeback date to submit the second presentment. The merchant’s operational deadline may be shorter and should be confirmed with the acquirer.
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