Learn what to do if you can't remember your AT&T online account management User ID.
Use Forgot User ID/Password link
If you do not remember your AT&T online account management User ID, try our Forgot User ID/Password? link found on the Sign In page. Select the User ID option, enter your main telephone number, select the Continue button, and then follow the instructions to retrieve your User ID.
If you do not remember the Email Address associated with your account, you will need to contact us and describe the situation. Be sure to include as much information as possible: your billing telephone number, your current email address, and any previous email addresses.