I made the unfortunate mistake of buying a Galaxy S5 through AT&T and was rewarded with a locked bootloader and no fun whatsoever for any reason ever.

As a remedy, I've considered purchasing a T-Mobile Galaxy S5 and somehow unlocking it (how does that process work again?) for use on AT&T.

Two questions:

  1. Will it be compatible with most (if not all) bands on AT&T? (ie: will I lack anything or will I be able to use the network just as well as with the AT&T S5?)
  2. How do I unlock a device for use on a different carrier?

According to AT&T, these are the supported bands for the AT&T S5:

  1. 4G-LTE: 1, 2, 3, 4, 5, 7, and 17
  2. 4G: HSPA+ with enhanced backhaul
  3. 3G - UTMS: 840, 1900, 2100MHz
  4. GSM/GPRS/EDGE: 850, 900, 1800, 1900MHz

According to T-Mobile, these are the supported bands for the T-Mobile S5:

  1. LTE: 1, 2, 3, 4, 5, 7, 8, and 17
  2. UMTS: Band 1 (2100), Band 2 (1900), Band 4 (1700/2100), Band 5 (850)
  3. "Quad Band GSM" (what bands?)

It seems to be compatible.

See also AT&T Radio Frequencies and T-Mobile Radio Frequencies

Will it work?


Yes. T-mobile S5 is my daily driver. I have a T-mo SIM card in it, but every time I go on a road trip up north T-mo contracts their service out to AT&T and my S5 connects to AT&T's towers, telling me so in the notification pulldown bar and the lockscreen.

  • I've been using mine on AT&T for a year now. Feb 3 '16 at 3:50

Okay, here's what I can gather...

  1. There should be no real loss of capability if you move to AT&T. While AT&T does not advertise LTE Band 8 capability on its S5s, Band 8 is largely used in South Korea, Japan, and Taiwan; unless you travel to those places, it shouldn't be a problem. I would, however, check AT&T's coverage map to be certain.

  2. T-Mobile allows customers to unlock phones provided certain conditions are met. Click here for more information.

Also, "Quad Band GSM" on T-Mobile is 850/900/1800/1900 MHz, same as AT&T

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