The customer service phone number for GoPhone is 1-800-901-9878, as of 2015. The phone line is open Monday to Friday, 7:00 a.m. to 10:00 p.m and on Saturday and Sunday from 9:00 a.m. to 7:00 p.m. Customers can also manage accounts online at ATT.com.
GoPhone has an online support website that allows users to estimate data usage, add money and manage their balances. GoPhone offers prepaid cellphones and other devices with no annual contracts. Customers also have the option to use their own devices. The service is provided by AT&T Mobility and operates on its wireless network, which has the strongest LTE signal in the United States.