ATT

United States ★★★ Verified Customer: 611

AT&T is the third-largest mobile operator in the US, owned by AT&T Inc., founded 1885 (originally American Telephone & Telegraph). Around 27% market share. Provides nationwide 4G LTE / 5G. USSD *777# for balance (prepaid), *225# for bill balance (postpaid), *646# for minutes usage, *3282# for data/SMS usage, *#06# for IMEI, *#21# for call forwarding, *#43# for call waiting, *#123# for roaming status. myAT&T app for self-service. Customer care 611.