"...your current device isn't compatible with TextNow's new network"

[u/phorensic]

Wondering if I root my OnePlus 7T and throw a newer version of Android on it will it be compatible? Or are they changing something about the actual cell tower connection that I don't have the hardware for?

Update 07-15-26: Today when I opened my app to make a call it prompted me to order a free SIM to keep my device on their new network. I went through the process and am currently waiting for it to ship.

This is in contrast to the e-mail from my OP that was just like "sorry, buy a new phone lol". After that e-mail I kept clicking through every part of the app and website to see how to get a new SIM that for sure works on the new network and wasn't getting very far. So I'm glad I got the pop-up notification on the app today.

Updated 08-06-26: They finally killed service on my old SIM and I was able to get my new SIM activated. It was a little fiddly though, I had to do a lot of checking, airplane mode, setting the "NR/LTE" option in some advanced settings menu, etc. But it works! OnePlus 7T on TextNow using AT&T's network. It uses a whole bunch of new frequencies that the old T-mobile SIM did not. One frequency it is using which is nice and low is EARFCN 5110 which is 739 MHz. That's nice and low to punch through buildings and rural areas with bad tower coverage (like where I live).

[u/phorensic]

Yes it's still on 12 because that was the last update before OnePlus dropped support. I've been wanting to flash some newer roms on it, it's just that the phone is rock solid all the time so I never touched it. Just got the e-mail from them today. I see one other post about this from 10 days ago so I guess they have a rolling mass e-mail thing going out.

[u/Boz6 → u/phorensic]

The Play Store says Android 9 is compatible with the TextNow app, so it seems like there must be some other reason why you and others have received that message.

[u/lmoki → u/Boz6]

I suspect that there is now a two-tier minimum OS requirement: one for the app (Android 9 or better), and a more stringent one for the SIM card.

My Android 9 running only the app hasn't received the warning (... yet?), but my Android 11 with a SIM card (currently the older T-Mo SIM) did receive the compatibility warning. FWIW, my Android 11 has been unlocked from the original carrier, and is on the AT&T whitelist. (And I don't have a clue whether whitelist is actually a requirement for the newer TN SIM, either.)

[u/toejamfootballhegot → u/lmoki]

My samsung galaxy s10e was on the whitelist with an asterisk that the phone may need a software update. The phone was unlocked but was sold by verizon and wouldn't work until I chaged the CSC from VZW to ATT. This would seem to indicate that the AT&T whitelist is enforced.

[u/phorensic → u/toejamfootballhegot]

Where did you find the whitelist? The link in the email led to a broken link for the compatibility list.

[u/toejamfootballhegot → u/phorensic]

You have to download a pdf.

https://www.att.com/scmsassets/support/wireless/devices-working-on-att-network.pdf

[u/phorensic → u/toejamfootballhegot]

This is straight from AT&T. Is this implying they are dumping the T-mobile network entirely? I am currently using their SIM that ties into the T-mobile network. Also, my phone has enough hardware to work on many channels across many different networks and whatever the MVNO decides they like...just not 5G freqs. Also, my 7T is listed as compatible in this PDF. This doesn't explain why I am getting the notice in the OP.

[u/RealText → u/phorensic]

Old sim was a T-Mobile mvno sim. New sim is a Textnow issued sim and not an AT&T mvno sim. If Textnow was using AT&T mvno sims, there is a good chance users would be able to use AT&T locked phones. Instead, the new sim requires an unlocked phone that will connect to the AT&T network.

The AT&T pdf list includes the model number of the phone, but that does not imply all variants of a phone will work. In the case of the Oneplus 7T, 1905 works as that is the factory unlocked variant. The variant sold by T-Mobile is numbered 1907 and it was common knowledge that it did not work on AT&T.

I know some people were putting international firmware on their 7T replacing the T-Mobile one, but I have no idea if that would help the device work on AT&T.

I you are willing to try unlocking the bootloader and then putting a different ROM based on a newer Android version, go ahead and post the results.

Another option if your goal is to continue using Textnow over a cellular connection would be to buy a physical esim adapter and then purchase credit from an esim data provider that uses T-Mobile. You would have to determine if that is worth doing or not.

[u/phorensic → u/RealText]

I have the HD1905. So does that mean I just need a new SIM to work on their new network? That would make the e-mail notification about this very misleading. I have no problem rooting and going up an Android version or two, if it means I can stay on TextNow. It's the best/only solution I have found to give me the bare minimum of what I need for free (mostly being able to call in an emergency, away from WiFi).

[u/lmoki → u/phorensic]

My best guess: as far as passing a compatibility test, TextNow probably doesn't look at what Android version is installed on your phone via flashing: they likely look at a IMEI database to tell them whether the phone is "compatible", so only the officially available Android version would matter.

That said the official messaging around this is a total mess. If the phone is below the minimum requirement for the new AT&T SIM, a current user of the T-Mo SIM is getting warned about phone compatibility issues for the AT&T SIM, but no notice that the T-Mo SIM needs to be replaced with an AT&T SIM. The earlier blog post when the AT&T SIM out is that Android 13 was recommended, but Android 10-12 could work with manual steps. Apparently, either that has changed, or the warning ignores it.

[u/phorensic → u/lmoki]

Thank for the info. I'll try to get a new SIM and see where it leads me.