This article will guide you through paying your AT&T phone bill, whether you’re using an app, a web browser, or another method. That’s it! You’re done. At least until next month … Good work: you’ve paid your bill! At least, your phone bill. Your AT&T home internet bill is another story. You can also pay your AT&T bill through text message by signing up for TXT-2-PAY. Once you’re signed up for this service, AT&T will send you a text message six days before your payment is due. You can simply reply to the message to make your payment using the method you’ve set up. You can pay your AT&T phone bill by snail mail like this: Now you can sit back, relax, and let the USPS do its job. Keep in mind it can take up to 10 days for the payment to be received. While you’re paying your bill in person, you can ask questions about your account and maybe upgrade to an unlimited data plan.