If the credit card is used for bill installment, it must be accounted for before installment, so it can't be phased without accounting. Unbilled means that the bank has not issued a bill to the user before the next bill date. The billing date is the date when the user's credit card consumption amount was settled last month. The bank will send the bill to the user after the settlement on this day, and then repay the money according to the amount on the bill.

Installment means that the user can't pay off the bill at one time and apply to the bank for installment repayment. However, it is necessary to bear the corresponding interest and handling fees, and the bank may refuse, so it is necessary to apply in installments in advance, which can avoid the overdue situation caused by the failure to pay the bill.