Older iphone switching from AT&T to T-Mobile

[zacdilone]

Hi everyone...excuse my newbiness. Been on AT&T for decades because of work. New job, can finally switch.

But here's my problem--I need wifi calling because of crappy signal in our neighborhood. My unlocked iPhone 6 will be fine since AT&T already had wifi calling enabled. Only 6/6S or newer get wifi calling on AT&T.

But the other two phones on my account, a 5C and a 5S, while eligible on T-Mobile for wifi calling, have it disabled on the AT&T branded phones. If I want to make that feature available on these phones, do I have to jailbreak it? Does it involve changing the firmware? Is it even possible to remove the embedded restrictions AT&T put on them?

Any help is greatly appreciated!

 

[Applejuiced]

If your iPhone's are unlocked you dont have to worry about AT&T's wifi calling restrictions.
You can do wifi calling on Tmobile with all these devices above. 5C, 5S and iphone 6.
AT&T's restrictions do not carry down, once you put in a Tmobile sim inside and the phone is unlocked then the Tmobile carrier settings get enabled on that phone.
So in other words you'll be fine and you dont have to do anything special to enable wifi calling on Tmobile.

 

[tys]

Looks like 5S supports it.
https://support.t-mobile.com/docs/DOC-31830
5C too:
https://support.t-mobile.com/docs/DOC-31008

I know it works on my iPhone 6+ but not my iPhone 5.
Even on my 6+ purchased from T-mo, it's still kind of hit or miss. Often need to toggle wifi and/or wifi calling off & on to get it to work.

 

[Samanosuke]

As long as your devices are unlocked they should work with wifi calling.

 

[chscag]

I know for a fact that WiFi calling on a 5c with T-Mobile works. My last two phones were 5c models and we used them for WiFi calling all the time we had them. And yes, as long as they are unlocked or T-Mobile phones it will work.