The main card can be used after the secondary card is charged. The main card and the secondary card use the unified account payment, any number is paid for the unified account,1 card payment more cards are available. The main and secondary cards are interacted. Therefore, after the sub-card is charged, the main card can also be used.
If the main card is a joint account user, the balance of the main card on the secondary card can be used, the specific details are recommended to contact the home Unicom customer service.