What does it mean that Unicom cards can be pre-deposited?

Available pre-deposit refers to the communication service fee pre-deposited by customers with China Unicom, which is used to pay customers' various communication service usage fees.

Use of available advance payment:

(1) can pay all the phone charges generated during the use of your mobile phone, including SMS charges, phone charges, traffic charges and monthly mobile phone rent.

(2) You can order some related membership services and traffic package services that support subscription. These membership services can be handled through the mobile phone business hall or by telephone.