If you’re looking to permanently unlock your Galaxy S5 to use on a different GSM-based carrier, UnlockUnit (not affiliated with Gadget Unit, by the way) has a fast and reliable service for you to check out. If you’d like to unlock a device other than the GS5, they support hundreds of other devices.
Video Review/Unlock Walkthrough
The unlock ran me $31.99. Shortly after I paid for it via PayPal, I received a generic confirmation email from UnlockUnit. Exactly 93 minutes later, I received a second email that contained two codes that are specific to my AT&T-locked Galaxy S5: NCK, FREEZE. Since I had a spare T-Mobile micro-SIM available, and tried that in the phone.
After turning the phone off, swapping out the AT&T micro-SIM with the T-Mobile one and turning the phone back on, it said that I needed to enter a network unlock code. I entered the NCK code that came in the second email from UnlockUnit, and the phone immediately had T-Mobile service.
Calls, SMS and MMS worked fine, but there was no data connection. To fix that, I simply had to edit the phone’s existing T-Mobile data APN from epc.tmobile.com to fast.t-mobile.com. After saving the changes, within 5 seconds, the statusbar showed the 4G LTE icon, meaning the phone had LTE data service. I did a quick TestMy.Net download test, and received 28Mbps on just 2 bars (that’s quite speedy given the signal strength), which is typical for T-Mobile’s LTE in my area (quite a bit faster than AT&T in the same areas, though). One thing to note, in particular for the AT&T Galaxy S5, is that it doesn’t support T-Mobile’s AWS HSPA+ bands for “4G”/3G. If you live in an area with “refarmed” PCS HSPA+ spectrum, you’ll receive that for 3G/”4G” data. GPRS and EDGE worked fine (tested by forcing those connections).
All told, UnlockUnit came through as you’d expect them to. While their unlock doesn’t seem to be that cheap, it’s not outrageously priced. The codes arrived quickly, and everything ultimately worked just fine.