How To Guide Carrier/SIM Unlock - Galaxy S21 Ultra 5G SM-G998U & U1 (QualComm SnapDragon) USA/CANADA! - NO ROOT- FREE

[K0mraid3]

Here's a free How-To on how i successfully Carrier/Sim unlocked my Samsung Galaxy S21 Ultra 5G running the NEWEST Android update on bootloader 5 (USQU5BULJ)released in January of 2022 that was carrier locked to Verizon and now fully Unlocked.


DISCLAIMER:
*This does NOT trip Knox or Void your warranty and does NOT require a root or a paid service. **This is the process I took, you may find some of these steps are not needed but for the purpose or recreating my results, I'll be posting my exact process.***This has ONLY BEEN TESTED ON SNAPDRAGON BASED SAMSUNG GALAXY S21 ULTRA 5G SM-G998 U & U1, if you try it on a different model or phone you may (and likely will) receive different results!!!!


You can read more on how this method works to force a carrier update to your device, here, on the Official Android dev site.

Here's what you'll need:
•ANY (activated or not) Sim from the carrier you wish to switch too.(or a way to replicate the carriers cert from one)
•A computer
•Patched Odin
•BOTH the NEWEST U & U1 ROMs/Firmware - theres a full post on these and how to flash them here, Stock Firmware and ODIN Flashing Guide (XDA) or visit SamFW.com, it has both Odin and the ROM/Firmware files you will need.
•(Optional?) Android ADB platform tools (You can find them on the official Android Developers page here or use any ADB software of your choice, fastboot is not required or used in this process. Link: Android Dev Platform Tools (Official)


Step 1:
So let's presume you have a Verizon or T-Mobile carrier locked phone, if you look at your baseband, which you can find in Settings > About > Software Info, you should see this "SM-G998Uxxxxxxx"

NOTE:
It Is CRITICAL that we flash the U1 rom BEFORE putting in the desired carriers SIM, then reboot, let phone fully boot, ONLY THEN should we insert the desired carriers SIM.

Step 1b:
Head over to your preferred site to get stock Samsung Roms (Refer to link above if you don't know where to find) and download the U1 XAA rom and the U rom of the CARRIER YOU WISH TO USE.


IMPORTANT! MAKE SURE YOU DOWNLOAD BOTH THE "U" ROM FOR THE CARRIER YOU WISH TO SWITCH TO AND THE U1 UNLOCKED (XAA) ROM/Firmware.

IF YOU ALREADY HAVE U1 FIRMWARE
I.e "SM-G998U1xxxxxxx" - you can skip to step 2, but I would recommend reading through the next part.


Put you device in download mode (Hold Vol up and Vol down and plug in the USB, which should be connected to your PC and now your phone at this point.)

Flash the U1 XAA Rom, place appropriate files in appropriate places in Odin, when you get to CSC, DO NOT use the "HOME_CSC" use the other.

Leave the rest of Odin settings alone and hit Start, wait for it to finish and reboot.


Step 2:
Once the phone boots, return to Settings>About>Software and confirm the device is now showing the "U1_XAA" in the Service Provider Software Version - it should say something like "SM-G998U1_XAA blah blah blah" - you just want to see the "U1" bit.

Now put in the Sim from the carrier you desire. A pop-up should appear prompting you to restart your device.


! CRITICALLY IMPORTANT STEP !
We will now initiate a reboot, but BEFORE the device fully restarts, we need to force it into RECOVERY MODE, I was able to achieve this by holding the power and Vol Down buttons at the same time, starting to hold them directly after the "Samsung" Logo fades away upon initial restart. If you have trouble getting into recovery, please comment below.


Once in recovery, use the volume keys to navigate to "Clear Cache" select and execute. Now go to Factory Data Reset/Wipe, select and execute. It should be the option directly above "Clear cache".

Once done, go up to "Reboot to Bootloader", Select & Execute.


AGAIN, Very Important step! We MUST interrupt the boot process again and force the phone BACK into download mode this time, so once the phone attempts to reboot, we need to hold the Vol Down and Vol Up buttons at the same time and the USB MUST be already plugged in, essentially it should remain plugged in throughout this process.

We should now be back in download mode and be on "U1" as we have verified in the steps above.


STEP 3:
Now it's time to flash the ROM/Firmware from the carrier you wish to use. Make SURE you have the SIM from the same carrier inserted during this process as mentioned at the beginning. It doesn't need to be a working or activated SIM, just simply one from the carrier you wish to have this S21 work on.


Flash all items from the "U" ROM/Firmware as you did earlier, ensuring to use the "U" ROM/Firmware for your desired carrier as described above. Same deal with CSC here, DO NOT use the "Home_CSC", use the other.
BE SURE that you use the USERDATA file that comes with the "U" ROM/Firmware. Its Critical in order to get the phone working properly on the new carrier.

Start the Odin flashing process & wait.
Phone will Auto-Reboot.....

Done!


You should now be on the carrier you wish to use.
This can be (in theory, test at own risk) replicated for ANY carrier supported by Samsung.


Please comment your experiences/ issues etc below. Don't be afraid to ask for clarity of something.

PoC, results after doing above process pictured in this screenshot.

Good luck.
-k0mrade

Send me Crypto if I helped?

Before process, this message would appear shortly after inserting a new SIM in testing devices:



After preforming above procedures I now find pictured below by running this activity:
com.samsung.ssu.unlock.MainActivity



And verify twice by checking my work in Settings>About>Software Information> Service Provider Software Version & Carrier Configuration Version.



For anyone whos still having trouble, try following the directions on this thread. Maybe they explain it a bit better or their process omits/includes parts ive missed.

Alternative Guide To Carrier Unlocking S21

Good Luck.

 

[K0mraid3]

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[iBowToAndroid]

Have you attempted this on lower bootloader revisions?

 

[K0mraid3]

Have you attempted this on lower bootloader revisions?

I have not. But am very interested to see how it goes if you or anyone decides to give it a shot, it SHOULD work on any BL considering the method of attack. But I can't verify it does.

 

[xDpakaX]

Hello. I did everything as in the guide. I downloaded U1 firmware for XAA, but for some reason CCT remains on the phone. Also in the step where to insert the Sim, my phone does not ask me to reboot the device.

 

[K0mraid3]

Hello. I did everything as in the guide. I downloaded U1 firmware for XAA, but for some reason XAS remains on the phone. Also in the step where to insert the Sim, my phone does not ask me to reboot the device.

Have you tried doing a normal reboot and forcing into recovery first, wipe cache, factory reset, reboot to Bootloader, then before full boot force into download mode with your SIM from the carrier you want to go to already inserted and downloading the "U" Firmware for the carrier you want and flashing it? What does Odin and/or your Baseband in settings say after doing above e process?

 

[Proverbs2]

Thanks for the guide! Is there any chance this process might also work on other phones? I have a Samsung Galaxy XCover Pro that I've been trying to unlock for months. I've called Verizon many times, and they claim they already unlocked it, but when I put another sim in I still get the message "Sorry, your device can't be activated on another carrier's network right now. For help, contact Verizon at (800) 922-0204 or (888) 294-6804 (prepaid plans)."

 

[iBowToAndroid]

Thanks for the guide! Is there any chance this process might also work on other phones? I have a Samsung Galaxy XCover Pro that I've been trying to unlock for months. I've called Verizon many times, and they claim they already unlocked it, but when I put another sim in I still get the message "Sorry, your device can't be activated on another carrier's network right now. For help, contact Verizon at (800) 922-0204 or (888) 294-6804 (prepaid plans)."

What's the Baseband Version?

 

[Proverbs2]

What's the Baseband Version?

 

[iBowToAndroid]

@Proverbs2 it can be done with a computer, but not with the method listed above. It would have to be done by a professional business that offers SIM unlocking, so it wouldn't be free. If you want to have it done, don't do any more software updates until after it's unlocked

 

[Proverbs2]

@Proverbs2 it can be done with a computer, but not with the method listed above. It would have to be done by a professional business that offers SIM unlocking, so it wouldn't be free. If you want to have it done, don't do any more software updates until after it's unlocked

Thanks! I tried paying a service to unlock it already, but they were unable to unlock it and refunded my money. I unlocked the bootloader and rooted the phone before getting the sim unlocked, unfortunately, so none of the usual methods seem to work.

 

[iBowToAndroid]

Thanks! I tried paying a service to unlock it already, but they were unable to unlock it and refunded my money. I unlocked the bootloader and rooted the phone before getting the sim unlocked, unfortunately, so none of the usual methods seem to work.

Yep then you're screwed. It can't done if Knox is tripped

 

[K0mraid3]

Thanks for the guide! Is there any chance this process might also work on other phones? I have a Samsung Galaxy XCover Pro that I've been trying to unlock for months. I've called Verizon many times, and they claim they already unlocked it, but when I put another sim in I still get the message "Sorry, your device can't be activated on another carrier's network right now. For help, contact Verizon at (800) 922-0204 or (888) 294-6804 (prepaid plans)."

Hmm I have not tried it, but, in all reality, I used this exact same method YEARS ago on my S7 Edge and it worked then. I have not tried it on another Samsung but I'd imagine anything other then the newest flagship would probably be quite simple to fix as there should already plenty of resources available via Github and such. If you take it on let me know, I'll do what I can to help.
If you want to test it out on your device, i see no reason why it shouldnt work if done correctly, but you may have to play with the order in which you interrupt the bootloader and force the update. Even if you have tripped Knox, there is indeed a way to completely disable Knox all together and not get locked out of the device. I did it on the S21 that I unlocked when I was mucking about on the phone. But that's an entire different tutorial and I'd need people to test it on other Samsung devices. But I'd be happy to share that too if you'd like.

 

[K0mraid3]

Thanks! I tried paying a service to unlock it already, but they were unable to unlock it and refunded my money. I unlocked the bootloader and rooted the phone before getting the sim unlocked, unfortunately, so none of the usual methods seem to work.

Is it still unlocked and rooted? That would make life another easier. We can repair the IMEI, baseband etc. It's worth a go if the phones just a paper weight right now imo. But ultimately up to you.

 

[Proverbs2]

Hmm I have not tried it, but, in all reality, I used this exact same method YEARS ago on my S7 Edge and it worked then. I have not tried it on another Samsung but I'd imagine anything other then the newest flagship would probably be quite simple to fix as there should already plenty of resources available via Github and such. If you take it on let me know, I'll do what I can to help.
If you want to test it out on your device, i see no reason why it shouldnt work if done correctly, but you may have to play with the order in which you interrupt the bootloader and force the update. Even if you have tripped Knox, there is indeed a way to completely disable Knox all together and not get locked out of the device. I did it on the S21 that I unlocked when I was mucking about on the phone. But that's an entire different tutorial and I'd need people to test it on other Samsung devices. But I'd be happy to share that too if you'd like.

Thank you! I'll give it a try and report how it goes.

 

[K0mraid3]

Good luck! Worst case, look up a program called "Samsung TFT Module", just be sure to scan it for viruses and bad code if you have the ability.unless you are able to find the 2022 update of it, you'll have to settle for whatever version is available. It'll likely be old, clunky and out-of-date, half the program defunct, but a few key parts still work, and quite well. Don't forget ADB drivers. Let us know how it goes!

Thank you! I'll give it a try and report how it goes.

 

[Proverbs2]

Ok, I tried to follow each step carefully, but I had to make one minor change to the procedure: after flashing the U1_XAA firmware, I had to power off the phone in order to insert the SIM card. (In the XCover Pro, the SIM card slot is obstructed by the battery, so there is no way to insert the card without powering off the phone and removing the battery.) After inserting the card, I booted directly into recovery and followed the other steps from there.

Unfortunately, it didn't work for me: the phone is still locked, showing the same message: "Sorry, your device can't be activated on another carrier's network..." Perhaps that's because I wasn't able to perform that one critical step, inserting the sim card while the phone is turned on. Any suggestions for a workaround?

 

[xDpakaX]

Have you tried doing a normal reboot and forcing into recovery first, wipe cache, factory reset, reboot to Bootloader, then before full boot force into download mode with your SIM from the carrier you want to go to already inserted and downloading the "U" Firmware for the carrier you want and flashing it? What does Odin and/or your Baseband in settings say after doing above e process?

Yes, I followed the guide. The problem is that when I'm on U1 my phone doesn't ask me to reboot.

 

[Pisuk]

Hello. I did all on VZW SQU3AUDB phone. Did all steps.
I have question. But in first start after step 3 (i flash G998U VZW) i see: Sorry, your devic.... verizon message

STEP3: Now it's time to flash the ROM/Firmware from the carrier you wish to use

It min - i need to flash not VZW ROM? some other? I need to use Ukrainia operator sim. Or i need flash G998W or else?

can someone help me?

 

[Lowlifexalvin]

Does my bootloader need to be unlocked