Legal analysis: Mortgage card is a kind of bank card, but it is not a credit card. The main function of the mortgage card is as a special account, which is convenient for banks to deduct the monthly mortgage payment.

legal basis: article 667 of the civil code of the people's Republic of China

a loan contract is a contract in which the borrower borrows money from the lender, returns the loan at maturity and pays interest.

article 68 it is forbidden to lend at high interest, and the interest rate of the loan shall not violate the relevant provisions of the state. If there is no agreement on the payment of interest in the loan contract, it shall be deemed that there is no interest. If the loan contract is not clear about the payment of interest, and the parties cannot reach a supplementary agreement, the interest shall be determined according to the local or the parties' trading methods, trading habits, market interest rates and other factors; Borrowing between natural persons is deemed to have no interest.