Reason code

This reason code was used when a transaction was processed using an account number that the issuer did not recognize or have on file. This typically indicated that the transaction was unauthorized due to an invalid or non-existent account number.

However, Mastercard has discontinued Reason Code 4812, merging its use into Reason Code 4808: Authorization-Related Chargeback. This consolidation aims to streamline the chargeback process by categorizing all authorization-related disputes under a single 

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To address a chargeback under Reason Code 4808 (which now encompasses the scenarios previously covered by 4812), you should provide evidence that the transaction was properly authorized. This may include:​

• Authorization Approval Codes: Documentation showing that the transaction received an approval code from the issuer at the time of processing.​
  

• Transaction Records: Detailed records indicating that the account number used was valid and matched the cardholder's information on file.

• Proof of Card Present Transaction​: For in-person transactions, evidence that the card was swiped, dipped, or tapped, and that EMV protocols were followed if applicable.

To minimize the risk of authorization-related chargebacks under code 4812 (now 4808):

• Ensure Proper Authorization: Always obtain authorization approval for every transaction, and do not proceed with transactions that receive a decline response.​
  
  
• Use EMV-Compliant Terminals: Utilize chip-enabled terminals to process card-present transactions, reducing the risk of counterfeit fraud.​
  
  
• Avoid Manual Keying: Minimize manual entry of card information to reduce the risk of errors and unauthorized transactions.​
  
  
• Stay Updated on Account Status: Regularly update and verify account information to ensure transactions are processed with valid account numbers.

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