Apn

No. If your phone is not compatible, changing the apn settings won’t change that. Now if your phone is compatible but data isn’t working, different apn settings might help that.

APN is settings for data and MMS.  It will not resolve compatibility or allow HD voice on incompatible phones. 

What phone are you trying to use? 

Brand, model name and model number. 

Is it for a different service provider? 

I have a Verizon unlocked phone. LG v-30. They say it's not compatible. When I put the sum card in a change the apn I can get internet but no phone calls. I easily get 4g LTE no problem with this phone. Do I need to change the network mode to GMSN from my current Globel setting.

Your phone is not compatible for HDVoice on ATT which is ATT’s version of VoLTE and is required for phone calls. 

Hello Scrain, we're here to help you with your unlocked LG V-30.

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

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
  • Solution 1
  • Solution 2

Just added

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:

1. Go to Settings > About Phone.
2. Scroll down to Service provider SW ver.
3. The first section shows the sale code.
4. The second section shows the Network Code.
5. The third section shows the Carrier ID.

Let us know if this helps.

Thank you for visiting AT&T Community Forums!

Carlton, AT&T Community Specialist