Visa reason code 12.6.1 is used when a cardholder claims they were charged more than once for the same transaction. This often occurs due to system errors, manual keying mistakes, or retrying a transaction without voiding the original.
These disputes are fairly common and usually easy to resolve if the merchant can show that each charge was for a separate, valid transaction. However, if the duplicate charge isn’t caught and corrected quickly, it can lead to a chargeback—even if the original purchase was legitimate.
If the charges were not duplicates, provide documentation showing that each transaction was valid and distinct:
Reduce the risk of duplicate processing with system checks and careful procedures: