Account number: It can be found in the upper right corner on any bill or invoice that you may have, in your online account. For bundled bills, the account number will be a 12-digit number under your wireless account summary.

PIN: It is usually the last four digits of your telephone number. It is not on your bill, invoice, or online account. You can call AT&T at +1 (800) 331-0500. For bundled bills, the account number will be a 12-digit number under your wireless account summary. Also, only for bundled bills, call AT&T customer service for a 4-digit PIN.