AT&T Troubleshooting | Librem 5

Hello Purism Community,
       I hope this message finds you well.
I have been utilizing the Librem 5 for some time now. However, it appears to be having some issues supporting cellular data (mobile broadband) with the American cellular provider AT&T (sometimes reffered to as ATT).
Texting and phone calls appear to work as expected.

Ever so often the company texts me the following message:

Hi, it’s AT&T. The device you tried to
activate does not work on our network.
We’re here to help. Go to
for more info and learn how to stay

Is there anything I can do to help remedy this? The sim card was taken directly from my previous Android smartphone and had been utilized on Lineage OS and Android machines without issues.

Thank you so much for all of your time and support!

Additional Details:

  • Location: United States (primarily West-Coast/Arizona)
  • Modem Purchased with Device: Librem 5 Modem - BM818-A1

I am on contract with them or else I might look into other providers.

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You can use AweSIM, which also uses the AT&T backbone:

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Make sure your Network Mode (under Settings-Mobile) is set to 4G Only

If AT&T detects the phone trying to connect with anything else, I think that triggers the message.


This is true.


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Since all U.S. carriers shut down their 3G networks a couple of years ago, and 2G before that (except for T-mobile, which still retains limited 2G coverage), they require Voice Over LTE (VoLTE) to be operational on any device they activate. With no 3G networks remaining, devices that are unable to make Voice-Over-LTE/4G calls have no network to fall back to for calling (with the exception of 2G on T-mobile).

AT&T calls its particular VoLTE implementation “HD Voice” and takes it a step further by actually publishing a limited list of devices (PDF) that they will allow to operate on their network. Anecdotally (from comments in their support forums) they are known to disable call functionality for unapproved devices they detect on their network. They are able to spot an unapproved phone via the device’s IMEI, which is always observable to any network.

Verizon is similarly restrictive, even if they don’t publish an actual list.

T-mobile is more accepting of VoLTE-capable devices that were not originally branded (and/or locked) to their network. T-mobile is not known to disable calling when they detect an already-activated SIM in a non-VoLTE device on their network, but they (likely) won’t activate it for new service. As they still have limited 2G/GSM as a fallback, a customer with such a device may still be able to make calls, but may have frequent connection issues.

Although Purism’s AweSIM/SIMple plans, through an intermediary provider, now use AT&T’s network for service for the Librem 5 (and/or other devices if desired), they are able to bypass AT&T’s usual restriction.

All of the Librem 5’s BM818 modem variants do have VoLTE functionality, and in the U.S. the BM818-A1 is easily activated on T-mobile’s network, or with MVNOs that use T-mobile’s network for service. Additionally, at least one forum member here reported success with using an already-activated SIM card from Pure Talk, an MVNO on AT&T’s network, which is an interesting exception.

It’s unlikely that you will be able to use AT&T itself for the foreseeable future.

(Note that having 4G data is not the same as having Voice over LTE/4G.)


In addition to the existing posts …

Complain to your congresscritter, asking Congress to make AT&T’s behaviour illegal?

Filtering by IMEI is at best lazy, and may even encourage people to alter their IMEI on those phones where that is possible (which in turn may be illegal).


I was using an older OnePlus when AT&T started the approved devices listing. There was no technical reason my phone wouldn’t work but it wasn’t on the approved devices list. I was upset by this enough to swap to T-Mobile. I have not regretted it.

Think about the e-waste alone generated by AT&T customers because there device wasn’t an approved device.


… which is another reason why this should be made illegal.

Yeah, I get it, you moved to a different network. That’s the easy “solution”. However it doesn’t fix the underlying problem and it simply isn’t an option for everyone i.e. if in an area where the only reasonable coverage is on AT&T’s network.

If noone complains, it won’t get fixed.

But then in my country at the moment we are generating a heap of e-waste from the looming 3G shutdown, with similar “device lists”. (I have a feeling that some people will throw away their perfectly good mobile phone not because the phone won’t work with 4G but because they can’t find it on a list either way and don’t want to take the risk of waiting until the shutdown and potentially being without a working phone.)


I agree that the phone restrictions are at best a terrible greedy policy. I can also confirm as mentioned above that my VoLTE has been working on the Pure Talk AT&T MVNO. My only explanation is that maybe they have to be less restrictive for their resellers. In any case, I should get coverage everywhere that AT&T works. Hopefully more people can get this working, so they have an option if they are in an area where AT&T is the only reliable network. And I would honestly think it wold be a selling point for an MVNO to show themselves as an option for Librem 5 users.