AT&T landline phone support can be contacted at 800-288-2020, 8 a.m. to 7 p.m., Monday through Friday and 8 a.m. to 5 p.m. on Saturday, as of July 2015. Technical support is available at the same number 24 hours per day, seven days per week.
AT&T provides live chat support on its website, ATT.com. Customers can access the live chat by clicking Contact Us at the bottom of the home page and selecting Landline on the next page. The Live Chat link is displayed on the right side of the contact page. AT&T also provides troubleshooting tools, frequently asked questions and videos on the contact page.