Unlocked AT&T Model on TMO. Drawbacks?

[PhoenixMike]

Not sure if this is in the right forum. Please move if it's not.

Title sums it up. I plan on using an unlock code on my AT&T S8+ and go back to TMobile since I was actually getting better coverage.

I searched around Google and couldn't find any solid info on popping in a TMO SIM. Someone mentioned flashing but losing WiFi Calling and VoLTE but was vague.

Any help would be greatly appreciated.

 

[mary beth hale]

Last year I used a T-Mobile sim in my old unlocked AT&T Note 4. Data, LTE, MMS and signal strength were fine. I know I couldn't get Wi-Fi calling but don't remember if I had VoLTE.
Hopefully someone can speak to your question about the S8 Plus specifically.

 

[mary beth hale]

I think to get Wi-Fi calling you have to flash the T-Mobile firmware.

 

[PhoenixMike]

I think to get Wi-Fi calling you have to flash the T-Mobile firmware.

Thanks. I was just going to week it you had flashed the firmware.

 

[mary beth hale]

No. My unlocked was still AT&T firmware. From what I've read though, flashing the T-Mobile firmware will allow T-Mobile carrier exclusive capabilities.

 

[anon(123856)]

I think to get Wi-Fi calling you have to flash the T-Mobile firmware.

My S8+ plus is unlocked but when I switched to TMo from Verizon I got a notice to reboot once it detected the sim and I now have WiFi calling. Might not be the case with the AT&T version.

 

[mary beth hale]

My S8+ plus is unlocked but when I switched to TMo from Verizon I got a notice to reboot once it detected the sim and I now have WiFi calling. Might not be the case with the AT&T version.

That's awesome. I'm sure things have changed since I had the T-Mobile sim in my old unlocked AT&T Note 4. Hopefully OP gets the same experience on the AT&T model as you did on your unlocked model.
BTW... Despite missing the Oreo Beta a bit on my departed S8, I am loving this S8 Plus!

 

[PhoenixMike]

Thanks for the replies. Can anyone point me in the direction of some instructions ton flashing? I've been having bad luck with Googling. Keep finding international build files.

 

[mary beth hale]

Did you try SamMobile?

 

[PhoenixMike]

Did you try SamMobile?

I'm actually on it now. Only seeing international variants. Will keep at it.
Thanks

 

[mary beth hale]

I'm actually on it now. Only seeing international variants. Will keep at it.
Thanks

https://www.sammobile.com/firmwares/galaxy-s8/SM-G955U/

 

[anon(123856)]

That's awesome. I'm sure things have changed since I had the T-Mobile sim in my old unlocked AT&T Note 4. Hopefully OP gets the same experience on the AT&T model as you did on your unlocked model.
BTW... Despite missing the Oreo Beta a bit on my departed S8, I am loving this S8 Plus!

Yes I am loving the Plus as well. I never used to care for large phones but my aging eyes are much happier (even though the smaller S8's screen was excellent).

I'm seeing insanely good battery life. I'm not a power user and don't normally have battery issues but this thing has been awesome. Maybe I don't want the Oreo update!

 

[mary beth hale]

Oh yes... Crazy good battery life.

 

[mary beth hale]

I'm actually on it now. Only seeing international variants. Will keep at it.
Thanks

Did you ever have any success?