Database Info

Sprint + 955FD not compatible, no wifi calling

Bought 955FD myself here in saudi.
Followed instructions to make "cumulative 5 minute call" with middle east/north africa sim: regional unlock.
1st issue: wifi calling available?
Searched settings for wifi calling. Initially something pops up, such as an option but it asked for ?phone number? I dont recall, was too excited about getting ready to pop in sprint sim from edge6.
During this search i was waiting for smart switch to execute bringing files from edge6.
When its all done i see nothing about wifi calling on 955FD.
2nd issue: activating 955FD to Sprint network.
Called Sprint, they asked for HEX gave them the IMEI number, then informed phone is not compatible.
They informed me i could go into sprint store and have them flash the device to place it on sprint's system. But that didnt sound confident. The phone is not compatible but can be flashed.
I was told once before by sprint international they have special sims to be used on foreign devices. But after failed activation informed me the international sim would not work either. I am never satisfied with first tier help/information from sprint.
I am open any advice. Last hope is to switch to TMobile which i read in another xda forum it will work. But i am concerned about the wifi calling mainly.

If you're rooted, then flash the CSC selector and select TMB. It will bring you wifi calling and Volte in TMOBILE, Not sure Exynos model will support Sprint CDMA..
I'm using it in Tmobile.. Mine is G955F
Sent from my SM-G955F using Tapatalk

Not rooted. Never tried that before. Trying to stay away from that effort.
Must it be rooted to be used on Tmobile?

2nd issue: activating 955FD to Sprint network.
Called Sprint, they asked for HEX gave them the IMEI number, then informed phone is not compatible.
Click to expand...
Click to collapse
As SBR said above, Exynos does not support CDMA. Sprint is CDMA. Your rep was correct.

rkennison said:
As SBR said above, Exynos does not support CDMA. Sprint is CDMA. Your rep was correct.
Click to expand...
Click to collapse
Thank you. Would them offering to flash the device be worth a try for experimental purpose?

No. The Exynos chip does not support CDMA. That is only in the Qualcom chip. The problem lies in your CPU, not software.

You have two different types of cellular networks, CDMA and GSM. Sprint and Verizon use CDMA while everyone else (in the world) uses GSM.
Kind of just an FYI, in which case your phone will work on T-Mobile, but not sure about the extra steps with WiFi calling (though, if it's on these forums, then you should be set there too).

Will update about wifi calling feature after I speak to Mobile in few weeks upon returning to stattes.
Thanks.

955FD on T-Mobile
After signing up with Tmobile i am 99% all good. Only problem is no wifi calling feature has appeared.

J_blaze114 said:
After signing up with Tmobile i am 99% all good. Only problem is no wifi calling feature has appeared.
Click to expand...
Click to collapse
WiFi calling on TMobile requires the TMobile firmware (which isn't available on the 955FD model, obviously).
Even unlocked US phones from Samsung can't use WiFi calling on TMobile unless they flash TMobile firmware.
You cannot flash the TMobile firmware on your device.

Skander1998 said:
WiFi calling on TMobile requires the TMobile firmware (which isn't available on the 955FD model, obviously).
Even unlocked US phones from Samsung can't use WiFi calling on TMobile unless they flash TMobile firmware.
You cannot flash the TMobile firmware on your device.
Click to expand...
Click to collapse
So my only option is to use DIGITS app by tmobile. Not bad but overall happy with my choice to buy this model...so far.

WiFi Calling on Factory Unlocked S8+

A couple of weeks back, I purchased a factory unlocked S8+ Model #G955U1, Baseband Version G955U1EU1AQE3 (The AT&T Galaxy S8+ has different Model and Build #s), inserted my AT&T SIM card and have been using it since. Then I decided to activate WiFi calling, however, unlike my wife's iPhone 7, my Galaxy does not have the option to enable WiFi calling (this option should be under Settings>Connections). After some research, I found out that this a carrier feature which AT&T must provision. When I asked them to do it, they provisioned it on my wife's iPhone 7 but not on my Galaxy, so I called them again and asked them to provision it on the Galaxy. Although they insist that they did, the feature does not show up on under AT&T Devices (It shows up under the iPhone but not the Galaxy). After spending no less than two hours speaking to three agents, I learned that AT&T does not have in their data base the IMEI number of the Galaxy because it was not purchased through them. So obviously, not having an IMEI number, the WiFi calling feature is not going to be pushed to my Galaxy. Not being able to solve the problem, they escalated it to another level who is supposed to contact me two days from now. A friend purchased his Galaxy S8+ through AT&T and the WiFi calling option is there in Settings>Connection and he is able to toggle it on or off. When I used AT&T's IMEI Verification tool, the result was "Device is compatible but we cannot find matching SIM card".
Any and all input would be appreciated.

Same here. Looks like wifi calling is not a feature that is available on the unlocked version unfortunately. Same with using LTE while on calls and built in visual voicemail :/
You have some advantages going unlocked but you lose some things too.
Sent from my iPhone using Tapatalk

But you can always use Odin to flash the ATT firmware to the unlocked device. There's plenty of threads here regarding this very subject.

Mr. Orange 645 said:
But you can always use Odin to flash the ATT firmware to the unlocked device. There's plenty of threads here regarding this very subject.
Click to expand...
Click to collapse
True, just keep in mind that future att updates can't be done via OTA - which can be a pain too.
Sent from my iPhone using Tapatalk

With the unlocked s8+ i've found that wifi calling and volte only worked on T-Mobile, I tried it with T-Mo and verizon. It stinks that ATT cant be more like T-Mo with accepting non branded devices

Poison423 said:
With the unlocked s8+ i've found that wifi calling and volte only worked on T-Mobile, I tried it with T-Mo and verizon. It stinks that ATT cant be more like T-Mo with accepting non branded devices
Click to expand...
Click to collapse
Same here. No issues with wi-fi calling on T-Mobile network. I also have the same unlocked phone.

Edited. Read the thread

Gr8man001 said:
Same here. No issues with wi-fi calling on T-Mobile network. I also have the same unlocked phone.
Click to expand...
Click to collapse
I am pleasantly surprised and a bit puzzled because when I spoke to T-Mobile Tech yesterday, she could not confirm if WiFi calling will work on unlocked S8+. If I can be assured that it will work, I will switch to T-Mobile.
Please do me a great favor and check if your unlocked S8+ has the same Model and Build Numbers as mine. Here are my numbers:
Model #G955U1
SM-G955UZKAXAA
Baseband Version G955U1EU1AQE3
Thank you.

TheBoozer said:
I am pleasantly surprised and a bit puzzled because when I spoke to T-Mobile Tech yesterday, she could not confirm if WiFi calling will work on unlocked S8+. If I can be assured that it will work, I will switch to T-Mobile.
Please do me a great favor and check if your unlocked S8+ has the same Model and Build Numbers as mine. Here are my numbers:
Model #G955U1
SM-G955UZKAXAA
Baseband Version G955U1EU1AQE3
Thank you.
Click to expand...
Click to collapse
All the information you provided matched with my phone. As a matter of fact, I also tried my friends SIM who is on MVNO called Mint Mobile that runs on T-mobile network. Mint also allowed me to make wi-fi calling. I am surprised that t-mobile rep could not confirm this feature because this feature is on by default! If I don't want to make wifi calls, I have to turn it off. The only little annoying part is that you get constant notification," Calls will be made over WiFi". Even when you block this notification, it will reappear on the reboot

Gr8man001 said:
All the information you provided matched with my phone. As a matter of fact, I also tried my friends SIM who is on MVNO called Mint Mobile that runs on T-mobile network. Mint also allowed me to make wi-fi calling. I am surprised that t-mobile rep could not confirm this feature because this feature is on by default! If I don't want to make wifi calls, I have to turn it off. The only little annoying part is that you get constant notification," Calls will be made over WiFi". Even when you block this notification, it will reappear on the reboot
Click to expand...
Click to collapse
Thank you indeed for your response. When I got my S8+ and before inserting AT&T SIM, this feature was NOT listed under Settings>Connections. I was informed by a Samsung agent that the carriers will push this feature to the phone through their SIM after they provision the feature. So now since my SIM is AT&T and my phone is unlocked, and its IMEI number is not in AT&T's data base, I don't have the feature listed.

Unfortunately, I can't comment on at&t network. On t-mobile, I did not have to do anything except during the initial setup, I was asked if I was ok to make wifi phone calls when a wifi connection was available & the signal was strong. I still have the option not to use this feature. You may wantvto visit a t-mobile store or find a friend who is on t-mobile network. It might not be a bad idea to reset the phone (after backing up) when you get the new sim card. Good luck ?

Gr8man001 said:
Unfortunately, I can't comment on at&t network. On t-mobile, I did not have to do anything except during the initial setup, I was asked if I was ok to make wifi phone calls when a wifi connection was available & the signal was strong. I still have the option not to use this feature. You may wantvto visit a t-mobile store or find a friend who is on t-mobile network. It might not be a bad idea to reset the phone (after backing up) when you get the new sim card. Good luck ?
Click to expand...
Click to collapse
Very good advice, thank you again for all your help.

on my s8+ wifi calling option is found in the phone settings , simply open the phone app hit those 3 dots , choose settings and wifi calling is at the bottom of the options .

peekie said:
on my s8+ wifi calling option is found in the phone settings , simply open the phone app hit those 3 dots , choose settings and wifi calling is at the bottom of the options .
Click to expand...
Click to collapse
I switched yesterday from AT&T to T-Mobile and immediately the wifi calling showed up in Phone Settings as you mentioned. However before switching from AT&T to T-Mobile, wifi calling was not anywhere to be found.

TheBoozer said:
I switched yesterday from AT&T to T-Mobile and immediately the wifi calling showed up in Phone Settings as you mentioned. However before switching from AT&T to T-Mobile, wifi calling was not anywhere to be found.
Click to expand...
Click to collapse
That's because WiFi calling and VoLTE are not available on ATT using the US Unlocked device. You have to either buy an ATT carrier version, or flash the ATT firmware to your current device.

Try to reset to factory defaults with sim inside
I'm on Argentina and with unlocked software i got wifi calling when the device is set up with my sim inside

Mr. Orange 645 said:
That's because WiFi calling and VoLTE are not available on ATT using the US Unlocked device. You have to either buy an ATT carrier version, or flash the ATT firmware to your current device.
Click to expand...
Click to collapse
I found that after wasting several hours with AT&T's techs. The 3rd option is to dump AT&T and switch to a carrier that has wifi calling available for unlocked S8/S8+ phones such as T-Mobile.

Wi-Fi Calling works great for me
TheBoozer said:
A couple of weeks back, I purchased a factory unlocked S8+ Model #G955U1, Baseband Version G955U1EU1AQE3 (The AT&T Galaxy S8+ has different Model and Build #s), inserted my AT&T SIM card and have been using it since. Then I decided to activate WiFi calling, however, unlike my wife's iPhone 7, my Galaxy does not have the option to enable WiFi calling (this option should be under Settings>Connections). After some research, I found out that this a carrier feature which AT&T must provision. When I asked them to do it, they provisioned it on my wife's iPhone 7 but not on my Galaxy, so I called them again and asked them to provision it on the Galaxy. Although they insist that they did, the feature does not show up on under AT&T Devices (It shows up under the iPhone but not the Galaxy). After spending no less than two hours speaking to three agents, I learned that AT&T does not have in their data base the IMEI number of the Galaxy because it was not purchased through them. So obviously, not having an IMEI number, the WiFi calling feature is not going to be pushed to my Galaxy. Not being able to solve the problem, they escalated it to another level who is supposed to contact me two days from now. A friend purchased his Galaxy S8+ through AT&T and the WiFi calling option is there in Settings>Connection and he is able to toggle it on or off. When I used AT&T's IMEI Verification tool, the result was "Device is compatible but we cannot find matching SIM card".
Any and all input would be appreciated.
Click to expand...
Click to collapse
To access Wi-Fi calling you need to open your phone app and hit the settings button in the top right corner and then scroll all the way to the bottom and it will be there.

Goldenstreak76 said:
To access Wi-Fi calling you need to open your phone app and hit the settings button in the top right corner and then scroll all the way to the bottom and it will be there.
Click to expand...
Click to collapse
Unlocked US version it isn't there on AT&T.

This is a Samsung Issue not AT&T...according to Samsung
The following is a record of your online chat.
General Info
Chat start time November 15, 2017 3:42:19 PM EST
Chat end time November 15, 2017 4:00:23 PM EST
Duration (actual chatting time) 00:18:03
Operator Rohit K
Chat Transcript
Info: Thank you for choosing to chat with us. An agent will be with you shortly.
Info: You are now chatting with Rohit K.
Rohit K: Hi, thank you for reaching out to Samsung Technical Support. How may I assist you?
You: how do i turn on HD voice on my s8+ on the att network?
Rohit K: I'll help you with the required information.
You: wi fi calling
Rohit K: Here are the steps.
Rohit K: Go to Settings. Tap Advanced Calling under WIRELESS NETWORKS. Tap Advanced Calling again to turn it On or Off.
You: I've gone through the steps outlined in your Wi-Fi calling setup but when I do the search no wi-fi calling shows up in the search
Rohit K: Just to confirm, is it a unlocked phone?
You: yes
Rohit K: Unfortunately, we cannot use the wifi calling option on the unlocked phones. Samsung is working on this issue.
You: That's odd....you would think it would work better. HOw long has it been an issue?
You: I just got my phone yesterday
Rohit K: The WiFi calling feature is disabled on the unlocked phones, as we can use any carrier on the unlocked phones.
Rohit K: You'll find it on the carrier enabled phone.
You: How can I exchange this phone for a new att phone
Rohit K: May I know the place of purchase?
You: Samsung.com
Rohit K: Yes, you can return the phone with in 15 days from the date of purchase.
Rohit K: We have a dedicated order support team, for your convenience I'll share the contact number of our dedicated team. Once contact them, they'll help you in exchanging the phone.
Rohit K: you may call us toll-free at 855-726-8721,
seven days a week, 9 a.m.-9 p.m. EST with your order
number.

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.
Click to expand...
Click to collapse
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.
Click to expand...
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?
Click to expand...
Click to collapse
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.
Click to expand...
Click to collapse
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?
Click to expand...
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.
Click to expand...
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.
Click to expand...
Click to collapse
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)?
Click to expand...
Click to collapse
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?
Click to expand...
Click to collapse
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.
Click to expand...
Click to collapse
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.
Click to expand...
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?
Click to expand...
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.
Click to expand...
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.
Click to expand...
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...
Click to expand...
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.
Click to expand...
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.
Click to expand...
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?
Click to expand...
Click to collapse
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?
Click to expand...
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.
Click to expand...
Click to collapse
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...
Click to expand...
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.
Click to expand...
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.
Click to expand...
Click to collapse
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.
Click to expand...
Click to collapse

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.
Click to expand...
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