Using AT&T phone on T-Mobile?

[starrscream22]

Okay, I have a general question, can someone please help?

You can use your existing phone on T-Mobile network provided it is a GSM phone and unlocked.

I called T-Mobile and she said you can use AT&T phone on T-Mobile WITHOUT unlocking it because AT&T and T-Mobile have an existing service agreement. Yet, when I call my local store, they said it has to be unlocked regardless.

So which is true? Can I use at&t phone on t-mobile network just like that? Or it has to be unlocked no matter what.

Thanks.

 

[combatmedic870]

You should just wait till tomorrow and buy the tmobile version. Atleast you know the bootloader will not be locked.

 

[starrscream22]

You should just wait till tomorrow and buy the tmobile version. Atleast you know the bootloader will not be locked.

Yes, I will be buying t-mobile version tomorrow.
My question, is for another line where I want to use my existing phone from at&t.

Can it be used just like that? Or I have to get it unlocked first?

 

[mircury]

Yes, I will be buying t-mobile version tomorrow.
My question, is for another line where I want to use my existing phone from at&t.

Can it be used just like that? Or I have to get it unlocked first?

Need's to be unlocked. Maybe they were confused with roaming agreements. Tmobile has a roaming agreement with ATT to use some of their towers.

 

[boshindo]

Make sure the phone supports freq bands for Tmo. I believe you need 1700/2100 for the regular network and 1900 for their refarmed LTE.

 

[unlockingsky]

Yes, I will be buying t-mobile version tomorrow.
My question, is for another line where I want to use my existing phone from at&t.

Can it be used just like that? Or I have to get it unlocked first?

Need's to be unlocked. Maybe they were confused with roaming agreements. Tmobile has a roaming agreement with ATT to use some of their towers.

Make sure the phone supports freq bands for Tmo. I believe you need 1700/2100 for the regular network and 1900 for their refarmed LTE.

best to test it out yourself with tmo sim and note3. nothing like a good experiment.