Unlocked s21 Ultra showing as "Unknown Device" and not supporting 5G or Extended Range LTE on My Mobile account

I've got the same problem as I have in the past. 

Just to clarify we're talking about official  USA Samsung T-Mobile devices purchased in the USA from vendors other than T-Mobile directly and not dual sim international Samsung devices.

I purchased a T-Mobile Samsung S21U from Best Buy USA. It is not recognized by T-Mobile because the IMEI number is not in their system. 

Now this is a major problem for me because the IMEI needs to be in T-Mobiles system for a sim unlock request to be fulfilled. 

I had a similar issue in the past with T-Mobile Samsung devices bought from Samsung directly. T-Mobile claim they can't sim unlock the device because it's not in their system.  

I have already contacted T-Force via Twitter but have been told to wait at least 14 days to get a response. We'll see. 

Another issue I have noticed on the unlocked versions is RCS doesn't work with Samsung messages app. Workaround is moving to Google messages app but still 

On my phone, I can initiate a SIM Lock (haven't. cuz the T-Mobile is in slot 1), which is at a phone level, so the SIM can't be used in another phone or a 2nd SIM slot with a different EMEI No.

However, T-Mobile has applied a network SIM Lock on the SIM/EMEI in my slot 1.  I have a DSDS Dual Nano-SIM phone.

 The fix is a bit complicated, since I am somewhat on T-Moblie, but not Identifiable in their DB.

Very similar to my NMS acct issue where the IT staffer had access, and could add/delete/modify devices in the NMS, but from the GUI app, you couldn't find them at all.

T-Mobile needs to update their DB.  They're a global carrier, and have the resources to pull it off.

How did your phone get locked into T-Mobile just by putting in their SIM card. I ordered one from them and put it in and after a quick update my phone shows it's on their network but it's not locked. I can easily swap my SIM card. Plus when I had issues connecting I have them my IMEI number so they have it but it still does not show any info. But my wife's iPhobe does and both our phones (S20ULTRA for me and iPhone XS for her) were bought unlocked directly through the manufacture and we're initially on Verizon for 2 years before we switched to TMO. So there no rhyme or reason here. 

Hello to All,

I'm joining the Unknown Device list.  I purchased a brand-new Galaxy S21+ 5G 256GB DSDS Unlocked International phone that is 100% T-Mobile compatible.  I detected two issues:

1.  The Unknown device status - My phone and yours are not in their network DB.  Even though a SIM can be installed and activated, and we still get billed and must pay, but the network doesn't really know we are out there.  T-Mobile needs to cleanup their process to deal with BYOD - locked/unlocked device by gathering the requisite data: device, Serial N., EMEIs, and Freq Bands, etc. for entry into the network DB that runs things.
2. My phone is now network locked after the T-Mobile SIM was installed.  I've been told it's going to take 72+ hours to obtain the unlock code.  However, I have a DSDS (Dual Nano-SIM) phone and both of my EMEI numbers are valid, not blacklisted, and are NOT in the T-Mobile Network DB; and are NOT in the network DB, so that they can pull up my data based on my EMEI numbers.

Note:  I manage a complex NMS system for a large food supply shop, and when new IT staff join, they get admin level credentials and automatically gain access to the NMS system that monitors servers, WAN link, UPS, switches, etc.  So, when checking the DB for them via the NMS GUI, they aren't there, but if I access the records at the SQL query level, guess what they are there.  So, to correct the issues, I must advise them that an acct issue is present, delete their acct, and add them with a more restrictive policy to the NMS system via the GUI.  Now the system is fully aware of them.

Sorry for the long story, but to correct this issue, many users may end up in the same predicament that my IT staff deal with and may lose cellular service while T-Mobile is making these changes.  You can't have duplicate records present.

Not having the IMEI number is a bad excuse. I had to give it to them when I switched my unlocked S20Ultra from Verizon to TMobile. They sent me a new sim card for my wife and I which she has an unlocked iPhone she bought from Apple directly and after we were activated, it shows mine as unknown and hers as an iphone but they were both unlocked BYOD coming from another carrier. So why can't they just manually input the number when you give it to them. Sounds like just laziness. BTW my phone works great. It's in the 5G and even though the coverage has bit or miss issues (which I confirmed they were working on the network in that area) everything works great except the visual voicemail. I still can't get the default disabled and just use the TMobile one as a standalone. A little annoying. 

BYOD devices don't usually work for domestic roaming on T-Mobile due to the device not being a T-Mobile or US Cellular device in the case of West Virginia.  The device showing as an unknown device is normal for any device not sold to you by T-Mobile. 

GriffithMagenta wrote:

I just bought an unlocked S21 Ultra directly from Samsung.  It works great, including the tmobile voicemail app and RCS through the Google messages app.  It says I'm connected to 5G on the phone, and I get 150+mbps download from home on speedtest.net

The problem is that the tmobile account website shows this:

The problems with this is:

1. Most important: I have free phone repair insurance through my Uber Visa Signature credit card.  In the past, when I filed a claim, they required a screenshot of the account to show that I have the device I'm filing a claim for on the tmobile account that I pay monthly through my credit card.  I would have issues proving that I have an S21 Ultra on my tmobile account if it says "unknown device:"
2. I’m worried I’m not getting the best speeds or roaming experience if I were to take a road trip in a rural setting.  150mbps+ from home is good enough in the major city that I live in, and I’m sure it’ll be better if I get closer to the tmobile cell phone tower which is 3 blocks away.

How do I get this phone to show as "Samsung S21 Ultra" instead of "unknown device"?  I don't see any option online to specify this.

Not only that, but in areas covered by T-Mobile's partners you will have no service. This happened to my wife and me. Galaxy Note 20 ultra 5g and Galaxy S20 from samsung. We had no service in Clarksburg WV, when we contacted T-Mobile we were told it's because our devices were not purchased from T-Mobile, and as such are not allowed to roam on the US Cellular network where US Cellular provides domestic coverage for them. Just be aware.

I found in the More Connections options. And after hours of searching through duck. Go where T-Mobile's ads can't override your search, u have yo select yhe Temporary Network Unlock option so that ur device can access their "partner service providers" and actually use the FREE roaming feature. This was after SEVERAL calls to TMobile asking how to do it. They REFUSE to tell u how ot about that setting because of their advertizements, they have to allow ur roaming and unlock for FREE! They've been getting slapped by the Consumer Protection Law authorities over their FALSE adds about the best setvice coverage. The teick is, u have to fo the temp unlock in advance. I guess we should just assume we wont have service and unlock it ever 30 days when it goes back to default

boxerdad0420 wrote:

syaoran wrote:

Voidyourwarranty wrote:

This is not a manufacturing problem or a samsung problem its a t-mobile problem.  If you can look up your own imei number and get the model, so can t-mobile.  They just don't do it. Why they don't I can't comment on but be sure it would take about 60 seconds to manually look up your imei number and if they had someone put in a couple hours of work they could build the automation in easily so I have to believe its intentional.

Probably because it serves no purpose!  Whether your device shows up as what it is or an unknown device has absolutely zero impact on whether your device works or not with the service.  

You're right this is an issue within T-Mobile because I bought my S21 Ultra directly from T-Mobile they put the SIM card in and mine does not work with extended LTE in a quote limited service area and they're telling me I need to turn the airplane off and turn it back on so I can do roaming and I won't be charged I shouldn't have to my phone is set up for Auto

This can happen sometimes when I store hasn't turned in their IMEI list of devices sold or just lag for the new device to show up on your account.  If it has been more than a week and your T-Mobile purchased device still shows up as an unknown device.  Call Support and have them verify that the IMEI is in T-Mobile's system as a device sold to you by T-Mobile.