19 digits: it is a savings card, which is generally used for cash deposit of ordinary depositors. The main function of a savings card is to save deposits. Cardholders can read and manually enter passwords through the electronic payment network established by the bank and the magnetic stripe of the card, so as to realize credit card consumption, ATM withdrawal, transfer and various payment functions. The expenses incurred through the card are equal to the decrease in the balance of the savings account.
16: Longka dual-currency credit card (hereinafter referred to as "dual-currency credit card") is a series of Longka products issued by China Construction Bank (hereinafter referred to as "issuing bank"), which is issued by the issuing bank to the public. Cardholders can use the money first and then repay the money within the credit limit approved by the issuing bank, or at home (excluding Hong Kong, Macao and Taiwan, the same below) and abroad (including Hong Kong, Macao and Taiwan, the same below).