If it is a card of China Merchants Bank, a savings card cannot be converted into a credit card. At present, China Merchants Bank issues smart cards and credit cards. One-card debit card is a savings card, which deposits first and then consumes; Credit card refers to a credit card, which can be overdrawn, consumed first and repaid later. Because all-in-one cards and credit cards belong to different types of cards, all-in-one cards cannot be directly converted into credit cards and need to be handled separately.