So I’ve just had a chat with Tesco bank, they have said that since August 2024, Mastercard have changed their rules due to the high number of chargeback cases to do with gambling, basically getting rid of the code that is counted as wrong Mcc code, whereas visa still has this. Thats why people are having problems with Mastercard, online and on Mastercard website I’ve found this: Mastercard rule code 4846, which is "
Merchants who receive a chargeback for a transaction placed with a Mastercard card may encounter reason code 4846, which indicates an improperly processed transaction that the cardholder does not believe they should be responsible for paying"
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