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Flashing from Verizon to Tmobile. Please help with some clarification

Hello all! I have a s8+ from verizon. I am about to switch to T-Mobile at the end of this week. I have a spare unactivated T-Mobile sim and I have popped it in and it saw signal, and everything seemed good. Also with research I see that its appears just about 98% perfect. They say the HD Calling, and Wi-Fi calling are not working. I know I can flash the stock firmware from T-mobile and get those.
Here is the complication for me, I use Samsung Pay every single day, so I dont want to trip knox. Does flashing the firmware trip knox?

JediSamReye said:
Hello all! I have a s8+ from verizon. I am about to switch to T-Mobile at the end of this week. I have a spare unactivated T-Mobile sim and I have popped it in and it saw signal, and everything seemed good. Also with research I see that its appears just about 98% perfect. They say the HD Calling, and Wi-Fi calling are not working. I know I can flash the stock firmware from T-mobile and get those.
Here is the complication for me, I use Samsung Pay every single day, so I dont want to trip knox. Does flashing the firmware trip knox?
Click to expand...
Click to collapse
No flashing stock firmware doesn't trip Knox you'll be ok

funziebear said:
No flashing stock firmware doesn't trip Knox you'll be ok
Click to expand...
Click to collapse
Awesome thank you. So find a stock firmware, flash with odin, and drop in the tmobile sim and done right?
Also is there a good trusted place for the firmware? I normally do here or SamMobile but I havent been able to find it. Maybe my google fu isnt what it used to be

I'm going to be in the same boat will start looking into firmware, too!

Only way knox is tripped is by flashing a custom recovery.

JediSamReye said:
Hello all! I have a s8+ from verizon. I am about to switch to T-Mobile at the end of this week. I have a spare unactivated T-Mobile sim and I have popped it in and it saw signal, and everything seemed good. Also with research I see that its appears just about 98% perfect. They say the HD Calling, and Wi-Fi calling are not working. I know I can flash the stock firmware from T-mobile and get those.
Here is the complication for me, I use Samsung Pay every single day, so I dont want to trip knox. Does flashing the firmware trip knox?
Click to expand...
Click to collapse
Also I read that you might get hung up if you flash there's a thread that tells you how to do it properly on one of the s8 groups I say read that first just so u Don't have any issues

rando191 said:
I'm going to be in the same boat will start looking into firmware, too!
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http://www.firmwares.androidinfotec...g955u-g955usqu1aqd9-nougat-official-firmware/
Try here, I found this. But I am not quite brave enough to start this flash. Should be fine. But hard to risk this phone for me

Why do this as the phone has all bands and Sammy has an program that sets up for each carrier.

pego99 said:
Why do this as the phone has all bands and Sammy has an program that sets up for each carrier.
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What program might that be?
Sent from my Samsung Galaxy S8+

They are suppost to release it this year but I don't know what is called.

Curious, why u ditching verizon? I havs tmo and want to switch verizon. Tmo internet sucks some times. I know verizon is more expensive but i hate sending pic msgs. Have to wait to have good signal.

JediSamReye said:
http://www.firmwares.androidinfotec...g955u-g955usqu1aqd9-nougat-official-firmware/
Try here, I found this. But I am not quite brave enough to start this flash. Should be fine. But hard to risk this phone for me
Click to expand...
Click to collapse
Thanks- I'm also seeing some folks on other threads flashing the 955u1 XAA firmware and seeing positive results. Sounds like after they pop in their SIM, carrier details are downloaded. Just trying to get some items clarified before I do that.

I'm with Verizon I think T-Mobile is more hype than reality with coverage and speed.

I was able to get this working by following along with this thread: https://r.tapatalk.com/shareLink?ur...share_tid=3609487&share_fid=3793&share_type=t
Had to track down the eng boot for the 955u (which I can post when I'm home) but it was a simple as following all 25ish steps. I'm now fully TMB and have all features enabled. My phone does show TMB/TMB/VZW but all ims
and bands are enabled including volte, wifi calling and video calling.
Sent from my SM-G955U using Tapatalk

pego99 said:
I'm with Verizon I think T-Mobile is more hype than reality with coverage and speed.
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Hasn't been my experience since switching. In fact the same phones I had on Verizon get better battery life on tmobile since they aren't looking for service all the time.
Sent from my SM-G955U using Tapatalk

Getting AT&T features to work on unlocked S9+

Does anyone have a definite solution to this problem? I've read many opinions but haven't run across a solution. I have a Samsung unlocked S9+ running official AT&T firmware and userdata but the carrier specific apps and features still don't work. The best infomation I've found is that the IMEI numbers of the unlocked devices are not in AT&T system so the features/apps won't work.
If this is the case, has anyone had any luck getting AT&T to register their IMEI and get the features working?

What worked for me and others (see the at&t fw thread) is to call or chat with AT&T and give them a imei from a carrier branded phone(with your sim in, though this might not be required). Tell them you are trying to get wifi calling to activate and it is failing at the provisioning step and they will input your imei and it will reprovision. Then pull your sim and put it into your s9/+ running at&t fw and it will allow volte, wifi calling and call protect to work (these are the only ones I use).
Good luck

I talked with someone in AT&T technical support and they remoted directly into my phone, reset all app defaults and network settings.. This of course didn't fix anything so they opened a trouble ticket. They told me my IMEI was in their system and was OK. Haven't heard back yet.

why not just flash ATT U firmware?

I'm running AT&T official U firmware G965USQS2ARF4. What just occurred to me was that I didn't do a factory reset before or after applying it via ODIN.

Stuart R said:
I'm running AT&T official U firmware G965USQS2ARF4. What just occurred to me was that I didn't do a factory reset before or after applying it via ODIN.
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Just did that... Didn't help.

Stuart R said:
Does anyone have a definite solution to this problem? I've read many opinions but haven't run across a solution. I have a Samsung unlocked S9+ running official AT&T firmware and userdata but the carrier specific apps and features still don't work. The best infomation I've found is that the IMEI numbers of the unlocked devices are not in AT&T system so the features/apps won't work.
If this is the case, has anyone had any luck getting AT&T to register their IMEI and get the features working?
Click to expand...
Click to collapse
Stuart R said:
I talked with someone in AT&T technical support and they remoted directly into my phone, reset all app defaults and network settings.. This of course didn't fix anything so they opened a trouble ticket. They told me my IMEI was in their system and was OK. Haven't heard back yet.
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Click to collapse
Yes your IMEI is in their system. But it's not an IMEI from a branded ATT phone. You have to have the IMEI from an ATT phone like others have said, and like i had to do or you will not get the features, no matter what firmware you flash. This has been discussed in many threads. You have to have ATT change your IMEI in their system.
elliwigy said:
why not just flash ATT U firmware?
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Wont help unless you have a 965U or the IMEI from an ATT phone . ATT Features will not work on 965U1 IMEI. AT&T told me theses features wouldn't work on an unlocked phone and asked if i had the unlocked version. I told them no, it was an ATT phone i bought from Best Buy and it has an ATT logo (not the truth, got it from Samsung) and that i read in the forums that there were some issues with the S9 and that changing the IMEI fixed everyone's problems. I said i had my s8 here that everything works on and she said it's worth a shot to try and she changed mine in their system to the IMEI from my AT&T Branded S8 that i provided them. 965U1 has worked flawless ever since. All features work.

nugzo said:
Yes your IMEI is in their system. But it's not an IMEI from a branded ATT phone. You have to have the IMEI from an ATT phone like others have said, and like i had to do or you will not get the features, no matter what firmware you flash. This has been discussed in many threads. You have to have ATT change your IMEI in their system.
Wont help unless you have a 965U or the IMEI from an ATT phone . ATT Features will not work on 965U1 IMEI. AT&T told me theses features wouldn't work on an unlocked phone and asked if i had the unlocked version. I told them no, it was an ATT phone i bought from Best Buy and it has an ATT logo (not the truth, got it from Samsung) and that i read in the forums that there were some issues with the S9 and that changing the IMEI fixed everyone's problems. I said i had my s8 here that everything works on and she said it's worth a shot to try and she changed mine in their system to the IMEI from my AT&T Branded S8 that i provided them. 965U1 has worked flawless ever since. All features work.
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sounds about right.. i mean you can switch csc while on U1 depending on the sim card inserted but U1 isnt meznt to have all the carrier crap they need for the special features to work so u get the bare minimum..
while on U firmware, it seems the csc doesnt fully switch like they did on the S8 devices.. i tested this on my sim unlocked vzw s9+ with an att sim and a sprint sim and although data and calls worked,it stsyed on verizon bootani and bloat etc etc no matter what i did.. before on s8 devices after a reset it would have changed the boot ani,bloat and woulda had all the carrier features..
im also surprised they changed your imei lol.. i thought that was illegal lol.. i guess if the carrier does it then its fine haha

nugzo said:
Yes your IMEI is in their system. But it's not an IMEI from a branded ATT phone. You have to have the IMEI from an ATT phone like others have said, and like i had to do or you will not get the features, no matter what firmware you flash. This has been discussed in many threads. You have to have ATT change your IMEI in their system.
Hard to believe that they would just accept another IMEI and register it to your phone. I thought these were all unique numbers that couldn't be used on more than one device. How did that change affect the phone that originally had the branded IMEI?
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Click to collapse

Stuart R said:
nugzo said:
Yes your IMEI is in their system. But it's not an IMEI from a branded ATT phone. You have to have the IMEI from an ATT phone like others have said, and like i had to do or you will not get the features, no matter what firmware you flash. This has been discussed in many threads. You have to have ATT change your IMEI in their system.
Hard to believe that they would just accept another IMEI and register it to your phone. I thought these were all unique numbers that couldn't be used on more than one device. How did that change affect the phone that originally had the branded IMEI?
Click to expand...
Click to collapse
Didnt affect original s8 i used at all. or the s9. I replaced the s8 with the s9 when it came out so i just used the sim out of the s8 when the s9 arrived. s8 is just a spare phone now. I asked the operator if this would disable the other phone that the IMEI came from and she said no. I put sim from s9 in s8 afterwards just to test and it worked fine. They arent changing the IMEI of your actual s9, it still shows your original IMEI in your phone settings. They are just using the IMEI you provided on their end. What is actually going on behind the scenes i dont know. Maybe somebody that works in carrier support or may just have knowledge on how this actually works could chime in. I'm guessing they just use the IMEI to activate the features, since the unlocked one isn't eligible. I saw a better explanation in one of the firmware threads, if i run across it i'll post the link.
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Click to collapse

I will reiterate what is said above and clarify my post. You aren't asking the support team to change your phones imei. I think as stated previously that is a forbidden/illegal maneuver. The support request is to change the imei which is active in the at&t system as only carrier branded phones are able to use certain at&t features.
If you have an old AT&T phone its imei can be used to "trick" at&t into activation/provisioning. Then you can put your sim into a U1 phone using at&t firmware and use carrier specific features.
Hopefully, this is easier to understand and clears up some of the confusion I may have introduced in my original reply.

jay2o01 said:
I will reiterate what is said above and clarify my post. You aren't asking the support team to change your phones imei. I think as stated previously that is a forbidden/illegal maneuver. The support request is to change the imei which is active in the at&t system as only carrier branded phones are able to use certain at&t features.
If you have an old AT&T phone its imei can be used to "trick" at&t into activation/provisioning. Then you can put your sim into a U1 phone using at&t firmware and use carrier specific features.
Hopefully, this is easier to understand and clears up some of the confusion I may have introduced in my original reply.
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I presume I can use the IMEI from another brand of working AT&T phone such as an iPhone 6S (in this case, my wife's)?

Stuart R said:
I presume I can use the IMEI from another brand of working AT&T phone such as an iPhone 6S (in this case, my wife's)?
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Another thought... Say I get an old Galaxy S6 which uses the same size Nano SIM as my S9+. I move my S9+ SIM to the S6, update it to the latest AT&T firmware and enable WIFI calling. If I then move my SIM back to my S9+, will the carrier features now work?

Stuart R said:
Another thought... Say I get an old Galaxy S6 which uses the same size Nano SIM as my S9+. I move my S9+ SIM to the S6, update it to the latest AT&T firmware and enable WIFI calling. If I then move my SIM back to my S9+, will the carrier features now work?
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This is exactly what I'm doing. I use an older LG phone and the sim/IMEI then swap it to my u1 with AT&T fw after the device is provisioned.

jay2o01 said:
This is exactly what I'm doing. I use an older LG phone and the sim/IMEI then swap it to my u1 with AT&T fw after the device is provisioned.
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Glad to know that works. I can pick up an old AT&T S6 pretty cheaply on ebay. Guess I'll give that a try. Thanks

Download visual voicemail from apk mirrow

jay2o01 said:
This is exactly what I'm doing. I use an older LG phone and the sim/IMEI then swap it to my u1 with AT&T fw after the device is provisioned.
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Click to collapse
I previously had an AT&T branded S8+ with the same SIM that I'm using in the unbranded S9+ but I guess I never provisioned (enabled) WIFI calling. Dunno.

The "trick" of giving them an IMEI from an ATT branded phone doesn't usually work any more, maybe it used to, years ago.
This is why I won't buy OnePlus phones any more. I love their devices, best bang for the buck on the market, but no amount of my fiddling would get ATT to recognize it and provision VoLTE... so no wifi calling, no HD calling... when you make a call, your data drops to 3G, etc...
My Essential, somehow was on their "BYOD" plan and so it would give me VoLTE and HD calling, but no wifi calling. No wifi calling is stupid, because you aren't using their network at that point, so why should they even care?

SquireSCA said:
The "trick" of giving them an IMEI from an ATT branded phone doesn't usually work any more, maybe it used to, years ago.
This is why I won't buy OnePlus phones any more. I love their devices, best bang for the buck on the market, but no amount of my fiddling would get ATT to recognize it and provision VoLTE... so no wifi calling, no HD calling... when you make a call, your data drops to 3G, etc...
My Essential, somehow was on their "BYOD" plan and so it would give me VoLTE and HD calling, but no wifi calling. No wifi calling is stupid, because you aren't using their network at that point, so why should they even care?
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Click to collapse
"maybe it used to, years ago"... That doesn't apply in this context does it as carrier features VOLTE and Wi-Fi calling weren't even in existence years ago. And I'm not sure you have to give them anything. The claim by some is that just provisioning the features with your SIM on a branded device is enough.

Stuart R said:
"maybe it used to, years ago"... That doesn't apply in this context does it as carrier features VOLTE and Wi-Fi calling weren't even in existence years ago. And I'm not sure you have to give them anything. The claim by some is that just provisioning the features with your SIM on a branded device is enough.
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Click to collapse
And as someone who has repeatedly tried it, it doesn't seem to work. You can give them an IMEI from another phone, but it usually doesn't work. Either the IMEI is "on their list", or from a phone that is on the BYOD list, or it isn't. It's not the phone's fault, it is that AT&T is kinda being dicks about this... They want you to buy their phones, because most people sign a contract to get the cheaper price, or use their NEXT financing to spread the costs out. That creates a barrier to exit for most customers and protects AT&T's revenue stream from monthly invoices.
While bringing your own device makes them just as much money from the monthly bill, it doesn't help them "retain customers by locking them into a contract", so they usually don't give you full functionality...
I have had a working SIM from an ATT branded phone that was properly provisioned, popped it into my other device, and VoLTE went away. I would call them up and give them the IMEI from the phone, or one that I know worked, and still no go. The one exception was the Essential, and that was because for whatever reason, Essential went to the effort to get it on their BYOD list.
Trust me, if it was easy, I would be doing it and buying OnePlus phones exclusively every 6 months and that would be the end of it. LOL

Unlocked on T-Mobile

Hi!
Hey any functionality lost by using the unlocked version on T-Mobile ?
Thanks

When speaking to Samsung about this, they told me all T-Mobile bands are supported including 5G on the unlocked versions. What you may lose is video calling (who cares) and possibly wifi calling. But in the past I've seen threads were talking to higher-level techs at T-Mobile can enable those features.

I noticed Samsung checkout page didn't ask if you need a SIM for the unlocked phone. In the past it would give you an option. So curious if you will need to go to the store for a SIM.

Thanks . Video calling is big with me . Rats

My Note 9 was unlocked from Samsung but video calling and Wi-Fi calling work fine. Not sure about this phone though.

Won't you just be able to flash the T-Mobile firmware via Odin if you get the unlocked? Then you get the best of both worlds. This is what I did with my Note10+. Got the Unlocked from Samsung then used Odin to get the official T-mobile firmware.

BigMosley said:
Won't you just be able to flash the T-Mobile firmware via Odin if you get the unlocked? Then you get the best of both worlds. This is what I did with my Note10+. Got the Unlocked from Samsung then used Odin to get the official T-mobile firmware.
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Click to collapse
Same here

i had an unlocked note 10 + on tmo and had no issues with video calls or wifi calling. i got from the samsung site that the note 20 has an esim which i would guess is why you dont see any wording for a conventional sim...

marctronixx said:
i had an unlocked note 10 + on tmo and had no issues with video calls or wifi calling. i got from the samsung site that the note 20 has an esim which i would guess is why you dont see any wording for a conventional sim...
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Click to collapse
I currently use an unlocked note 10+ on tmo that isn't flashed. The only limitation is that I cannot do tmo-to-tmo video calling. It may simply be a setting on my end but I never looked into it as there are so many options. Everything else works fine and I seem to get every update at the same time.

Dewda said:
I currently use an unlocked note 10+ on tmo that isn't flashed. The only limitation is that I cannot do tmo-to-tmo video calling. It may simply be a setting on my end but I never looked into it as there are so many options. Everything else works fine and I seem to get every update at the same time.
Click to expand...
Click to collapse
To fix that issue you can flash TMobile rom onto the unlocked version.

jship said:
To fix that issue you can flash TMobile rom onto the unlocked version.
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Click to collapse
Thanks. I haven't flashed a rom before but there's lots of info available. If I don't upgrade to the Note 20 then I will flash the TMobile rom onto the Note 10+. If I do upgrade I will eventually flash the Note 20.

TMO user with S20 Ultra here. Don't use video calling so I could not say. Wifi calling works.
Third party VVM apps do NOT work and TMO's downloadable visual voice mail app is garbage IMHO.
When I put my VZW sim in the same phone the Samsung VVM app works beautifully.
Unlocked S20 Ultra 512GB here.
"5G" works on TMO where there is coverage however the speed tests show LTE as connection type. Interestingly enough some of the speed tests actually show 5G. Not sure what's going on with that. Have reached over 200Mbps down on TMO "5G" a few times. Most of the time it's the same speed as LTE. Don't care, it works, hot spot works nice too.
If you were to (properly) flash TMO firmware (in theory) it SHOULD make your phone just like a TMO bought phone including the cheesy jingle when booting up. Never tried it, I like the slim as possible approach. Plus the ability to drop in a VZW sim and it just works IS a MUST for me.

knuschit said:
When speaking to Samsung about this, they told me all T-Mobile bands are supported including 5G on the unlocked versions. What you may lose is video calling (who cares) and possibly wifi calling. But in the past I've seen threads were talking to higher-level techs at T-Mobile can enable those features.
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Click to collapse
You don't lose wifi calling or video calling using unlocked on TMO.
Sent from my SM-G986U1 using Tapatalk

bkeaver said:
You don't lose wifi calling or video calling using unlocked on TMO.
Sent from my SM-G986U1 using Tapatalk
Click to expand...
Click to collapse
What if anything do we loose?

a1atif said:
What if anything do we loose?
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I've been using unlocked devices on TMO for the past few years and everything works. I've not found anything that don't..
Sent from my SM-G986U1 using Tapatalk

tmobile visual voicemail has always worked for me on my samsung purchased unlocked 10+, so i guess our expectations are different.

Can't wait to see if I run into any issues with my unlocked on Sprint/Tmo

marctronixx said:
tmobile visual voicemail has always worked for me on my samsung purchased unlocked 10+, so i guess our expectations are different.
Click to expand...
Click to collapse
Only if you use TMO's downloaded app which is utter $4!+ IMHO.
I hate it so much I just dial in to listen the old fashioned way. I screen calls anyhow so the ONLY time it rings I know who is calling so not really a big deal. If callers don't have the secret PIN they get hung up on! F robos!

What about roaming on T Mobile partner network? Will I get a network on my UNLOCKED Galaxy Note 20 Ultra if I am roaming on US Cellular or any TMobile partner Network?
Will my Unlocked Galaxy Note 20 Ultra support all 5G bands from TMobile? (Low, Mid and High ) Layer Cake so to say.
What about SA 5G (Stand Alone 5G) that TMobile just launched. Will the Unlocked Galaxy Note 20 Ultra support it?

Sprint frequencies
I'm mostly concerned about the Sprint frequencies T-Mobile is picking up.

Unlocked Pre-Order from Samsung w ATT SIM - will I be able to use WiFi calling /VoLTE

Current Note8 user on ATT (phone locked to carrier). I pre-ordered a Note20 Ultra from Samsung direct, unlocked version. Have been off XDA really for a couple years and not rooting/modding much lately but have read that ATT will not allow unlocked phones on their network to use WiFi Calling and/or VoLTE. If true, are there workaround options for me (assuming I stick w ATT as the carrier I mean) to get these to work, or should I cancel the unlocked model and order the ATT version? Was hoping to root eventually and remove bloatware / play w custom ROMs again on the Ultra etc etc. - that is why I ordered an unlocked version.
Thanks gents for the guidance here! Best forum around for us phone geeks

If it will be like Note 9 or 10 plus just have to flash the U version csc with odin and it will give you wifi calling advanced..messaging..volte
Sent from my SM-N960U using Tapatalk

butchieboy said:
If it will be like Note 9 or 10 plus just have to flash the U version csc with odin and it will give you wifi calling advanced..messaging..volte
Sent from my SM-N960U using Tapatalk
Click to expand...
Click to collapse
Much thanks - I will do this then when it arrives.

Did not work for me on the unlocked note 10+. Worked right away on the tmobile.
Att was actually fun to have. Nothing that att expected worked on the unlocked device. For example I had unlimited hotspot, despite it was not included in my att plan.

Elastep said:
Did not work for me on the unlocked note 10+. Worked right away on the tmobile.
Att was actually fun to have. Nothing that att expected worked on the unlocked device. For example I had unlimited hotspot, despite it was not included in my att plan.
Click to expand...
Click to collapse
That's bizarre. I am rethinking this unlocked route. I must have wifi calling since signal at the house is terrible in my area. I don't need the drama of uncertainty if this will work or not. Might as well cancel the unlocked one and just upgrade via att. Oy. Wtf is with att these days? They lost my directv account last year and now their wireless policies are looking like a royal pita.

I don't think you have to worry .... ATT seems to consistently allow Samsung unlocked devices to have carrier functions
You just have to flash the U CSC as mentioned above. Worked for me on Note 10 and is currently working on a s20 ultra device

Jcrompton
Whats going on buddy. You jumping on the Ultra?
Sent from my SM-N975U using Tapatalk

I strongly recommend switching your order to the ATT model. I got my note 10+ unlocked based off the suggestions found here saying that flashing the att firmware would give me all the features, and I've been through a year of headaches.
For a little wile i was able to enjoy wifi calling, voicemail and VOLTE, but after my first software update the features were lost. i was able to get them back briefly by putting my sim back in an old Att phone and keeping it for a day or two, but that trick never lasted past a week. I've tried re-flashing the software, switching back to unlocked and then back to ATT, basically anything i could think of and it never worked.
calling ATT didn't help either, as the reps gave me a canned line about not supporting outside phones. the whole reason I'm updating to the 20 ultra is to just get my phone fully functional with an ATT model

Darthshadow666 said:
I strongly recommend switching your order to the ATT model. I got my note 10+ unlocked based off the suggestions found here saying that flashing the att firmware would give me all the features, and I've been through a year of headaches.
For a little wile i was able to enjoy wifi calling, voicemail and VOLTE, but after my first software update the features were lost. i was able to get them back briefly by putting my sim back in an old Att phone and keeping it for a day or two, but that trick never lasted past a week. I've tried re-flashing the software, switching back to unlocked and then back to ATT, basically anything i could think of and it never worked.
calling ATT didn't help either, as the reps gave me a canned line about not supporting outside phones. the whole reason I'm updating to the 20 ultra is to just get my phone fully functional with an ATT model
Click to expand...
Click to collapse
Thanks darth. Yeah, I switched to the att version. Hate the hidden tracking bloatware etc that comes with it but must have a very workable phone for daily work calls and wifi calling is a must. No drama is my motto these days. Thank you for reporting your experience.

I had the same situation with my unlocked Pixel 4 XL, keep calling ATT until I got the right person to modify my sim to allow WiFi Calling to work, that's my plan when I get my unlocked 20 Ultra.

I'm not a gent, but I doI have the Note 20 Ultra in for review and am using it with an AT&T SIM. VoLTE works, no option for WiFi calling.
jaxf250 said:
Current Note8 user on ATT (phone locked to carrier). I pre-ordered a Note20 Ultra from Samsung direct, unlocked version. Have been off XDA really for a couple years and not rooting/modding much lately but have read that ATT will not allow unlocked phones on their network to use WiFi Calling and/or VoLTE. If true, are there workaround options for me (assuming I stick w ATT as the carrier I mean) to get these to work, or should I cancel the unlocked model and order the ATT version? Was hoping to root eventually and remove bloatware / play w custom ROMs again on the Ultra etc etc. - that is why I ordered an unlocked version.
Thanks gents for the guidance here! Best forum around for us phone geeks
Click to expand...
Click to collapse

What worries me is the 5G. Will unlocked work for ATT 5G?

It does on my unlocked Galaxy S20+ 5G. The Note 20 Ultra is a ways to release and their system doesn't yet correctly identify the IMEI, so I can't say for sure what will happen after release day.
b00st4ddicted said:
What worries me is the 5G. Will unlocked work for ATT 5G?
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Click to collapse

pdagal said:
I'm not a gent, but I doI have the Note 20 Ultra in for review and am using it with an AT&T SIM. VoLTE works, no option for WiFi calling.
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Hi Lisa,
Your reviews are the best, so thank you first of all. Can you check if it has any eSIM capabilities? Supposedly S20 was going to get an update to allow eSIM use in US but that never happened...

Thanks . I'm not seeing anything under connection settings on our US unlocked Note 20 Ultra (there's no IMEI listed or cellular network option listed under connection settings when no nano SIM is installed. EsimClient is running on the phone, which makes me think the hardware must be there. EsimClient is not running on my GS 20+ unlocked.
VICosPhi said:
Hi Lisa,
Your reviews are the best, so thank you first of all. Can you check if it has any eSIM capabilities? Supposedly S20 was going to get an update to allow eSIM use in US but that never happened...
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Click to collapse

pdagal said:
Thanks . I'm not seeing anything under connection settings on our US unlocked Note 20 Ultra (there's no IMEI listed or cellular network option listed under connection settings when no nano SIM is installed. EsimClient is running on the phone, which makes me think the hardware must be there. EsimClient is not running on my GS 20+ unlocked.
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Click to collapse
Great, thank you for checking and comparing with S20+ !
eSIMClient running gives me hope that we will get eSIM support in an update...Still perplexed how or why Samsung has gone out of the way to disable eSIM on US variants when Apple, Google support it.

pdagal said:
I'm not a gent, but I doI have the Note 20 Ultra in for review and am using it with an AT&T SIM. VoLTE works, no option for WiFi calling.
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Ha! Thanks Lisa (love your tech vids!!) - I switched to the ATT version. Supposed to be here 8/21. I can't take a chance with wifi calling being borked, or that just that I may need to Odin-flash updates or CSC packs periodically to keep up with the monthly patches (ie force an unlocked unit to keep working on ATT's network if my previous firmware gets overwritten etc. I mean). I guess as I got older I went from a tech pioneer and adopter to just an end user LOL.... I just need it to work. Maybe I can do that package remove thingy and chop the bloatware periodically... we shall see once the community gets these units and starts their dev magic for us.
I guess I will need to make an appt at the local ATT store in a week to get on a new 5G plan from my current 4G one to take advantage of the coming speeds.

You're welcome- glad you enjoy our vids! With AT&T, you can simply change your plan online, no need to visit a store. The mid and high tier unlimited plans include 5G.
jaxf250 said:
Ha! Thanks Lisa (love your tech vids!!) - I switched to the ATT version. Supposed to be here 8/21. I can't take a chance with wifi calling being borked, or that just that I may need to Odin-flash updates or CSC packs periodically to keep up with the monthly patches (ie force an unlocked unit to keep working on ATT's network if my previous firmware gets overwritten etc. I mean). I guess as I got older I went from a tech pioneer and adopter to just an end user LOL.... I just need it to work. Maybe I can do that package remove thingy and chop the bloatware periodically... we shall see once the community gets these units and starts their dev magic for us.
I guess I will need to make an appt at the local ATT store in a week to get on a new 5G plan from my current 4G one to take advantage of the coming speeds.
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I flashed my unlocked Note 10 plus and didnt get wifi calling, visual voicemail, VOLTE.....only reason I am up grading is to get an ATT version, and to skip all the hassle of an unlocked version. Never again.

pdagal said:
I'm not a gent, but I doI have the Note 20 Ultra in for review and am using it with an AT&T SIM. VoLTE works, no option for WiFi calling.
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Click to collapse
Could you tell me more. I have the US unlocked note 20 ultra, I put an AT&T sim in (from my note 9 unlocked) and I can't find an option to turn on wifi calling. I pretty much gave up on feature like this, because I would rather have the unlocked phone, but if it works now maybe I am missing something.
Thanks
Sent from my Samsung SM-N960U1 using XDA Labs

AT&T vs Unlocked US version

Are there any differences (Hardware like LTE, 5G Band differences or software differences) between AT&T and US Unlocked versions?

Hardware should be no difference. Radio bands should be the same. Software is different. The unlocked comes without carrier bloatware.

That is correct. The software is the only difference. I had the Samsung Note 10+ unlocked on AT&T. I couldn't get WiFi call or HD voice. This time I went the Note 20 Ultra AT&T version. Not a big deal. I just remove the bloatware from the phone using ADB. You can find articles on how to do it.

Weird that I was told by VZW that I couldn't wifi call on the unlocked version. But I can.

I had the U1 version on ATT. Worked great. Some menus missing, such as ability to choose VOLTE butncall quality was great. Has to call ATT to change to a 5g plan for 5g.

By the unlocked version, are you referring to the SM-N986B/DS? I am researching as well and I am on the AT&T network.
Edit: my bad misread title.

I had a U1 N10+ and as someone else mentioned, no wifi calling or HD Voice (VOLTE). Even flashing the U firmware. ATT typically has to Whitelist your phone to unlock those features. Running the U would unlock Video Calling (useless unless the other person is also on ATT) and Advanced Messaging (also an ATT only service). The day I got my N20Ultra, I popped my ATT activated sim, and no VOLTE / HD voice, and no wifi calling. Being on U1, the rest of the features weren't available (video calling, advanced messaging, vvm) which isn't surprising since it's debranded.
In another thread, it showed that Factory Unlocked N20Ultra will have HD Voice hut NOT wifi calling. That's fairly new, so YMMV. Saw the post earlier this week. Not sure it's it's live already or in the works. Some phones had support for WiFi calling and HD Voice, but the N20 series were showing only HD Voice at time of article.
I've since dumped att for Metro (Tmobile) for a few reasons, but primarily their reluctance for fully support a factory unlocked device. They are making a step in the right direction, but honestly, VOLTE and WiFi Calling should be standard features supported. Like why wouldn't you want me to call on wifi instead of clogging the wireless towers? Both work OOTB with Tmobile.
Edit: If you have no plans to switch carriers, I'd get it through att. Even if you run U1 for now, you can change your mind later and know all the features will work on U. If you buy factory unlocked, and need WiFi calling, there's no guarantee it'll work even if you load U firmware. In the past, the device has to have the IMEI specifically whitelisted on their end.

todd3835 said:
I had a U1 N10+ and as someone else mentioned, no wifi calling or HD Voice (VOLTE). Even flashing the U firmware. ATT typically has to Whitelist your phone to unlock those features. Running the U would unlock Video Calling (useless unless the other person is also on ATT) and Advanced Messaging (also an ATT only service). The day I got my N20Ultra, I popped my ATT activated sim, and no VOLTE / HD voice, and no wifi calling. Being on U1, the rest of the features weren't available (video calling, advanced messaging, vvm) which isn't surprising since it's debranded.
In another thread, it showed that Factory Unlocked N20Ultra will have HD Voice hut NOT wifi calling. That's fairly new, so YMMV. Saw the post earlier this week. Not sure it's it's live already or in the works. Some phones had support for WiFi calling and HD Voice, but the N20 series were showing only HD Voice at time of article.
I've since dumped att for Metro (Tmobile) for a few reasons, but primarily their reluctance for fully support a factory unlocked device. They are making a step in the right direction, but honestly, VOLTE and WiFi Calling should be standard features supported. Like why wouldn't you want me to call on wifi instead of clogging the wireless towers? Both work OOTB with Tmobile.
Edit: If you have no plans to switch carriers, I'd get it through att. Even if you run U1 for now, you can change your mind later and know all the features will work on U. If you buy factory unlocked, and need WiFi calling, there's no guarantee it'll work even if you load U firmware. In the past, the device has to have the IMEI specifically whitelisted on their end.
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I spoke to AT&T for hours and they whitelisted my international Note20 Ultra IMEI. I still don't have Wi-Fi calling and they absolutely don't know why... I regret switching from T-Mobile to AT&T... but unfortunately have to stay with AT&T for 2 more years because of iPhone deals we got...

Guys, all you have to do is flash the U Home CSC for and you'll have all the features on ATT and still have U1 firmware on your U1 device. At least for me on this phone and two previous, the Samsung devices were already "whitelisted" with ATT

Can a US CSC be flashed to another snapdragon model, namely 9860?

ekerbuddyeker said:
Can a US CSC be flashed to another snapdragon model, namely 9860?
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My guess is no .... But not sure

So if I have a at&t version and flash the u1 firmware would I have wifi calling?

jjr3211 said:
So if I have a at&t version and flash the u1 firmware would I have wifi calling?
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No. If you're on the AT&T version, stay there.

I can't believe AT&T would whitelist all Samsung Unlocked devices, that would really surprise me. You can buy AT&T locked Galaxy phone and unlock it with AT&T since you bought it outright, and then of course it would be whitelisted.

Still Less Features for Factory Unlocked Models?
Read through this thread and tried digging around in all other logical forums and it seems that it's still the case that one cannot get WiFi calling on AT&T with a Factory Unlocked model?
Asking because Amazon is selling the Note 20 Ultra 512GB Factory Unlocked today for $1,200.
Found a Reddit thread that has people stating there will be a Samsung update that addresses this.
Have seen various posts in various places about flashing file(s)/ROM to enable this.
Any authoritative answer as to whether WiFi Calling (and Voice Over LTE) can be enabled on AT&T with a Factory Unlocked Note 20 Ultra? Or authoritative assurance it will, soon?

haroldlundt said:
Read through this thread and tried digging around in all other logical forums and it seems that it's still the case that one cannot get WiFi calling on AT&T with a Factory Unlocked model?
Asking because Amazon is selling the Note 20 Ultra 512GB Factory Unlocked today for $1,200.
Found a Reddit thread that has people stating there will be a Samsung update that addresses this.
Have seen various posts in various places about flashing file(s)/ROM to enable this.
Any authoritative answer as to whether WiFi Calling (and Voice Over LTE) can be enabled on AT&T with a Factory Unlocked Note 20 Ultra? Or authoritative assurance it will, soon?
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Click to collapse
They cannot. Att and att based subsidized carriers. Do not allow byod on votle or wifi calling. I have a trick to make it work for a couple hours. So I know its possible. But after a few hours their systems reprovision your device and shut them back off.

TheMadScientist said:
They cannot. Att and att based subsidized carriers. Do not allow byod on votle or wifi calling. I have a trick to make it work for a couple hours. So I know its possible. But after a few hours their systems reprovision your device and shut them back off.
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Too bad. Thanks for the reply. Feel better about passing up the sale especially since it will probably be a common sale price during Xmas sales.
And WiFi Calling is too important a feature to trade for a discount of a hundred or even two.

haroldlundt said:
Too bad. Thanks for the reply. Feel better about passing up the sale especially since it will probably be a common sale price during Xmas sales.
And WiFi Calling is too important a feature to trade for a discount of a hundred or even two.
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Yea. If you provision volte and wifi on a actual att phone and sim swap they work for a while. Usually around 4 or 5 am. Then it shuts off and never works again. Till sim swap and reprovision

VoLTE on unlocked Samsung S20 and Note20 series phones is set to "on" by default, but unchangeable (greyed out). As of right now, there is no ability to select WiFi calling until Samsung decides to grace those of us with unlocked phones that ability.

haroldlundt said:
Read through this thread and tried digging around in all other logical forums and it seems that it's still the case that one cannot get WiFi calling on AT&T with a Factory Unlocked model?
Asking because Amazon is selling the Note 20 Ultra 512GB Factory Unlocked today for $1,200.
Found a Reddit thread that has people stating there will be a Samsung update that addresses this.
Have seen various posts in various places about flashing file(s)/ROM to enable this.
Any authoritative answer as to whether WiFi Calling (and Voice Over LTE) can be enabled on AT&T with a Factory Unlocked Note 20 Ultra? Or authoritative assurance it will, soon?
Click to expand...
Click to collapse
There is a long term method but it involves calling att, and getting your IMEI registered so you can get VOLTE and wifi calling. Ask customer service. I can't remember the name of the department you need to request. It takes a couple of weeks and then you suddenly get a weird sms (something like IMEI provisioned) and then it works. Did it on note 9.