My 3G/4G Phone Is Not Working Anymore - Solutions & Help from the AT&T Community
Learn why your previously working device may have stopped working this February and how to determine if it's compatible
If you have a 3G device, please note, it will no longer work on the AT&T Network. If you have a 4G device, it may not be compatible and not work depending on where it was purchased and the model #. For example, the Galaxy S20 models G981U and G981U1 will work on the AT&T network, but the Galaxy S20 models G981F, G981N, and G981O will NOT work. You'll find a full list of compatible devices. This is because they have different hardware that is not compatible with AT&T’s network (HD Voice, VoLTE compatible).
If you purchased an unlocked device from another retailer, please note, they are not optimized to work on AT&T’s network. This is important to remember when purchasing a non-branded, unlocked device and why you see different model numbers.
Find the model number on your device
|1. Go to Settings.
2. Tap General.
3. Tap About to view the model name and number
|1. Go to Settings. You may have to go into the System menu next.
2. Tap About Phone or About Device to view the model name and number.
1. Go to Settings.
First, make sure your device is compatible with AT&T’s Network. If it is not on the list, it may not work on our network. In instances like this, you’ll need to get a compatible device.
If your device is compatible but is not connecting, the following may resolve the issues:
- Program the data settings for your non-AT&T device
- Get a 4G SIM for your 4G device or a 5G SIM for your 5G device
- Download the latest software – If you are an AT&T Customer, software downloads are automatic. If you have a non-branded device, you will need to go directly to the manufacturer.
- Make sure 4G is enabled on your device. Some customers disable 4G.
- Try a couple of solutions written by some community members
Samsung devices will have an update available via Samsung as late as June 2022. So if you brought your own device, please visit Samsung Support for update information.
Depending on the software, will determine if your device will work. If all troubleshooting and software updates have been performed, your device may need to be replaced.
How to find:
- Go to Settings > About Phone.
- Scroll down to Service provider SW ver.
- The first section shows the sale code.
- The second section shows the Network Code.
- The third section shows the Carrier ID.
|Type of Device||Device Persona||SIM Network Code||Original Device Carrier||Disposition|
|Verizon Device with Verizon SIM||VZW||VZW||VZW||Won’t work. Replace device|
|AT&T device with AT&T SIM||ATT||ATT||ATT||Will work.|
|Unknown origination with unknown||ATT||XAA||XAA||Will not work. Replace device.|
|T-Mobile device with AT&T SIM and persona||ATT||ATT||TMB||Will work.|
ChrisZ, AT&T Community Specialist