How does Shanghai Telecom check the phone bill?

Hello, telecom users can edit the SMS code 102 and send it to 100 1 to check the phone bill balance of the mobile phone card. They can also download and install mobile phones to check the phone bill balance. They can also check the phone bill balance through the telecom online business hall. Users can log in to the telecom online business hall and log in to their own telecom mobile phone number. After logging in, they will jump to the personal center, and then they can check their phone bill balance.