I have been a Manager with a third party ATT group for 5+ years. I have seen several situations, and have vast knowledge in ATT International travel questions. All the way from troubleshooting, to how international is billed as well as basic International travel questions on device usage.
Contact me for cruise ship information!!! Also, traveling to a country in the North American dialing pattern? Much useful information there. Gulf of Mexico roaming...very pricey, I have all the answers you need!
I can also help with many domestic issues....I was a small business manger as well for 2 years ...hit me up!
There are numerous ways this can be done, depending on what type of account you have. If you are on a contract based account (postpaid) and the phone is an upgrade, you will need to accept the terms and conditions for your device. The instructions would have come in the box with the toll-free number needed to call (usually on a bright orange or green piece of paper).
If the device is a warranty exchange, simply place your existing SIM card into the new phone to ensure it is working. You can visit the website online to update the IMEI number and SIM card if necessary. Logon to www.att.com/updatedevice and it will walk you through activating the new phone.
If the account is prepaid and you cannot do this online, or if the system is having issues, please call customer service at 800-331-0500 and they can assist you in activating the new phone.