Register for an AT&T U-verse account online after purchasing the required hardware. Both an account number and the passcode you received along with the order are required to set up and verify the associated account. Only the primary account holder can register for an account.
Once you have the passcode and account number, proceed with registration at the AT&T U-verse home page in a browser. Create a user ID using an email address, as well as a password. Alternatively, if you are using multiple AT&T services bundled together with the U-verse subscription, the registration process begins by activating your Access ID, logging in and using the Installation Technician for the self-installation option on the home page.