To check if the ESN or IMEI is clear on an AT&T phone, you first need to retrieve the number physically or by using the phone's software. Next, enter the IMEI on a third-party resale website to determine whether the phone is valid to use.
- Determine the IMEI
The IMEI is located under the battery on all AT&T phones. If it has been removed or obscured, dial *#06# from the handset. The IMEI is then displayed on the screen.
- Locate a third-party resale site
Go to Swappa.com or a similar site. Navigate to the ESN check area of the website.
- Enter the IMEI number
Once you have entered the IMEI number, the results are displayed within minutes. If these steps fail, contact AT&T customer service.