Can someone help me about Lumia 1520? Please

[Huy Pham2]

I'm planning to buy a Lumia 1520 for my birthday. I went to Microsoft store and ask for it. In the store, I heard that Lumia 1520 is only for AT&T while I'm using T-Mobile line with my auntie. They said this phone can be unlocked. But I heard form someone who already bought it that it's hard to unlock on AT&T and it has some problems with T-Mobile 4G LTE , only one model can use T-mobile 4G. I wanna ask some questions that:
1. How to unlock this phone and do I need to go to AT&T or just go some stores and unlock?
2. What model I should buy to use T-Mobile 4G and is it on Microsoft website?

 

[pankaj981]

Get the 1520.3

 

[JamesPTao]

I'm planning to buy a Lumia 1520 for my birthday. I went to Microsoft store and ask for it. In the store, I heard that Lumia 1520 is only for AT&T while I'm using T-Mobile line with my auntie. They said this phone can be unlocked. But I heard form someone who already bought it that it's hard to unlock on AT&T and it has some problems with T-Mobile 4G LTE , only one model can use T-mobile 4G. I wanna ask some questions that:
1. How to unlock this phone and do I need to go to AT&T or just go some stores and unlock?
2. What model I should buy to use T-Mobile 4G and is it on Microsoft website?

The 1520.3 is unlocked, has the tmobile bands, adds integrated qi charging, and has 32g onboard storage. Buy the 1520.3 not the 1520.