Definition of derived. biology. : being, possessing, or marked by a character (as the large brain in humans) not present in the ancestral form derived features.
Using other AT&T Payment Options. 1  1. Pay your bill via the automated phone system. Dial 1-800-288-2020 to access the 24 hour-a-day telephone customer service system. 2  2. Speak with a customer service representative. Once you have verified your phone number, the phone system will ask you what you would like to do.
AT&T Headquarters 208 S. Akard St. Dallas, TX 75202. 1  Phone Number: You can call the AT&T headquarters at 1-210-821-4105. 2  Email: When you click on the contact page on the corporate side of AT&T headquarters, you are taken to the contact information for the small business department within the company.