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Here is why you are not getting full LTE on AT&T when using the Lumia 950 XL

Over the last few days, people have been picking up the new Lumia 950 XL unlocked from Microsoft. The phone supports many LTE bands, which is why it is surprising to see a few people complaining about not getting LTE when they insert their AT&T SIM.

To be certain, the Lumia 950 XL dual-SIM does support AT&T's LTE bands. You can see it in action in our unboxing video. So why are some users having an issue? As it turns out, it can be a complicated mess that falls mostly in AT&T's lap.

Issue #1 – Setting up the phone without a SIM installed

Many times when you get a new phone you just want to turn it on and start using it. Additionally, you may want to set up the phone and use it for a few hours without a SIM to get a feel for it before committing your SIM to the phone.

However, skipping the SIM during the initial out-of-box setup may be a bad idea. We have set up our Lumia 950 XL twice with different AT&T SIMs and never had an issue getting LTE data speeds. It seems one common denominator with those getting non-LTE data is that they added the SIM after the setup. There may be a crucial step where the phone configures the APN settings during the initial setup, so it is best to start with the SIM when you take the Lumia 950 XL out of the box.

Hey, you can always pop out the SIM after and put it on your older phone until the Lumia 950 XL meets your criteria for usage.

Issue #2 – No IMEI for AT&T

The International Mobile Station Equipment Identity or IMEI is used to ID phones on a network. Did you never notice how your AT&T account settings "knows" what phone you are using? That falls on the IMEI.

AT&T keeps a list of IMEIs for the phones they official sell and support. The Lumia 950 XL is not amongst those they sell. If you call AT&T and tell them you are having issues with your unlocked Lumia 950 XL and you give that phone's IMEI, they will tell you they can't help and your phone won't work. This, however, is not true.

Many people in our forums have simply given IMEIs from other AT&T phones. One trick is just walk into an AT&T store and copy the IMEI from the AT&T Lumia 950 floor model. Others have used their older AT&T phones.

Once AT&T has an IMEI they can work with they can add it to your account and SIM. Once their system recognizes the IMEI, the LTE data should kick in. So much for open GSM standards, right? Remember, the IMEI does not matter on your end it is just a device ID and is independent of your SIM account number.

IMEI, where?

How to get an IMEI? On Windows Phone, it is always found under Settings > System > About > More Info and it should be listed near the MND and IMS numbers.

Now call AT&T support and tell them you have a new phone but your data isn't working. Provide them with the dummy IMEI from another AT&T phone and your SIM number. They'll add it to their system, and you should be good to go.

As user coolbreeze78 remarks in a forum thread on this topic "AT&T's system seems to require a branded AT&T LTE IMEI to be listed on your account for LTE provisioning to work". Once AT&T has this IMEI in their system you should be all set.

Interestingly, this LTE IMEI requirement seems to be only an AT&T issue, which is why those on T-Mobile do not seem to have the same problems.

Wrap up

To clarify again: The Microsoft Lumia 950 XL unlocked with dual-SIM 100% works on AT&T's network with LTE (although visual voicemail seems to be missing).

If you are only getting "4G" showing in the notification area on your Lumia 950 XL instead of "LTE", there is nothing wrong with the phone. Our Lumia 950 XL and many others are rolling just fine on AT&T. However, you do need to follow one or both steps above to make it work.

Most of the time the problems seem to come from picking up a new AT&T SIM and giving AT&T the IMEI from the Lumia 950 XL. Those who are migrating from an AT&T Lumia 1520, Lumia 920 or any other AT&T phone with LTE do not have these problems.

If you need more help on this or want to read other's experiences just jump into our help and support forums!

Order page for the Lumia 950 XL from Microsoft (opens in new tab)

Did you get your Lumia 950 XL in today? Let us know in comments your experience so far!

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Want all the latest news on these phones? Hit these topic pages for all that we got.

Daniel Rubino
Executive Editor

Daniel Rubino is the Executive Editor of Windows Central, head reviewer, podcast co-host, and analyst. He has been covering Microsoft here since 2007, back when this site was called WMExperts (and later Windows Phone Central). His interests include Windows, Microsoft Surface, laptops, next-gen computing, and arguing with people on the internet.

  • Now if only we could figure out a way to get visual voice mail working it would be perfect. This is an issue on AT&T as well as t-mobile.
  • That must be a problem with Win10 on the 950(edit:XL), because visual voicemail works fine on my ATT 1020 even though I'm using T-mobile.
  • My at&t 950 has visual voicemail... I got prompted to set it up the first time I manually called the voicemail
  • My at&t 950 has visual voicemail
  • It is a problem for the unlocked 950xl. Unlocked 1520.3 running W10 has no issues.
  • My 1020 has no more visual voicemail since I upgraded to the latest build.
  • Nope, it's not. I set visual voicemail upon my son's 950. It's a network feature and having an unlocked phone, means some features may not be supported, even if the phone can use the carriers' SIM. I'm not sure if it can be fixed, but maybe following solution#2 in the article for setup and then calling ATT or Tmobile and getting them to help get things set up will work to get visual voicemail working. Just a thought. I would also assume you may want to leave the XL part off, when they ask you what kind of phone you have.
  • After many hours of back and forth with AT&T on this on my dual SIM 640, a senior AT&T manager told me AT&T does not support Visual Voicemail on dual SIM phones. This is why I just took advantage of the $39.00 sale on 640's to buy another, a single SIM version and now Visual Voicemail works perfectly.
  • My 1520.3 unlocked visual voicemail works perfect.
  • The 1520 is a supported device, despite it being unlocked.
  • I think we can thank Verizon and their $3 a month visual voicemail stranglehold for those problems...
  • 1st time ive seen it reminded me of the same app rogers uses in Canada for their android handjobs.
  • I've had visual voicemail disappear when I've upgraded builds. Calling AT&T and having them fix it has always worked for me.
  • It seems to be a dual sim issue, not an unlocked issue. Users of 640XL dual sim seem to have the same, unlocked 1520.3 and 1020 CV work fine.
  • Yup. There's the irony if it. When I found out that I got a better version of the 950XL I thought it was pretty cool. Little did I know that this better version with dual SIM would actually take away a feature which I really liked. I'm actually considering returning it which is unfortunate because I really like this phone.
  • It has to do with the SIM card they gave is and activated. I've had this problem in the past when getting a secure sim card for ISIS payments :)
  • Why are you paying ISIS bro?...
  • Cricket too
  • My Latin America country variant of the 1320 gets visual voicemail on T-Mobile whether it's on 8.1 or the latest 10.
  • Must be a dual sim issue as others have suggested.  I have a single sim 950xl (international version), and visual voice mail is working on AT&T for me.
  • Thanks for the clarification, Daniel. Hopefully this helps people out. AT&T is a special snowflake for some reason. They really do hate unlocked devcies, and a Dual SIM one? Instant redheaded stepchild. Someone needs to remind them they are a GSM operator, which is supposed to be an open standard. Oh well.
  • Yup and thanks for you help in the forums. Definitely a messy situation.
  • I worked for an at&t call center for a few years in tech support. Unless they've changed from the then-new programs they were using then (Lumia 1020 era), providing a false IMEI may make the situation worse. What needs to happen is the customer provides the correct IMEI, and the customer service representative will follow the on-screen prompts to change the data plan to a generic one, as AT&T's data plans are phone-specific (iphonie, android, blackberry, Windows, etc.). This way the network recognizes the correct phone, and the correct data plan os in place for the phone type.
  • Sure, that should happen. However, as some users in our forum have experienced AT&T sometimes says they can't do anything about it and closes the case. Let's face it, it's a dumb system that is exacerbated by having under-trained employees. Customer loses each time.
  • *exacerbated
  • The only issue in the past was with iPhone and Blackberry IMEIs, since they used to have special plans that aligned with the phone's features. Just use an AT&T Android LTE phone IMEI. A store manager gave me this advice years ago, so AT&T has created this fiasco themselves. Maybe they should phone Legere to understand how T-Mobile's systems just work with any unlocked LTE phone's IMEI without hijinks. I know AT&T just loves their branded phones and really want to sell you one, but they are a GSM operator. Their systems shouldn't require jumping through hoops like this, but alas, they do. It's their issue and needs to be fixed. Until then, we resort to hacky workarounds.
  • Those pesky US carriers lol... Cheers for the info Coolbreeze78 and the PSA Daniel. Should help point people in the right direction.
  • Its really not that difficult. Your sims 9th and 10th digit must be 27 or higher first off with ATT for hd voice and lte support. After that the system has 3 main groups that provide you with LTE speeds and provision it to your actual phone line. The main 3 options are either for a general smartphone (windows phone, android etc), one specifically for Iphones and the final is for Blackberrys. Any imei provided for any phone within these 3 groups will provision you properly for LTE so long as the imei you provided is for a phone that ATT's system will recognize is LTE capable. Thats all there is to it. Cheers! One more thing. The data plan youre subscribed to determines whether youre provisioned for VVM as well or not. There are always 2 with VVM...and one with just basic voicemail.
  • I had this exact problem with my 950 xl. Went to ask at t store and he added an iPhone 5c imei and lte lot right up. Thanks for the help! I thought it was my phone. Att support was useless as you predicted.
  • & I remember non-tmo handsets didn't get apn settings automatically in various threads on here.
  • Why didn't they support the both models from the beginning if they were supporting W10M? It's not like Microsoft had them carry mill stones
  • OH AT&T, well at least the community has come together to help others fix this issue.
  • And what if we already did setup our phones without the SIM? Should we do a hard reset and start over once we get the SIM?
  • I'd first try it with the SIM to see if it works ;) If it doesn't try either one of those steps.
  • I'm in that boat too. Phone delivered on 25th and have been setting it up on WiFi because my work schedule hasn't allowed me time to get to a store yet. I wanted to have my phone setup BEFORE I switched it over. *fingers crossed.*
  • Mine says LTE but only getting 4 or 5 Mbps download. I was getting 30Mbps on my old phone. Something is not right. Everyone try to do a speed test to see if you're getting correct speed.
  • I just ran side by side tests on AT&T Lumia 950 and Lumia 950 XL on AT&T. Both were neck and neck for the same speeds even after running the tests multiple times. If there is a difference I cannot see it. Where i am I only average between 5-7 Mbps too, but it is consistent between both phones.
  • After I managed to make my LTE working I did notice the same thing and it bothers me. My speeds are in 5-8 Mbps range, although sometimes they can peak at 18. And now when I put my new SIM into an old phone I'm getting the same thing. And upload is consistently between 0.5-1.5 Mbps. But previously before I got my 950XL and changed the SIM card I did get much higher speeds, like TechAbstract says - something closer to 30Mbps down and at least 10Mbps up. My guess is they enabled some generic setting for LTE that works on some minimum. I don't know much about how this system works so it is purely my guess. As I am happy to get any LTE I still would like to see the normal speeds as I need it for work. I frequently send emails with big attachments and with ~1 Mbps upload it's not going to work very well. I hope they will work it out soon.
  • Under your sim settings there is an option to pull the carrier configurations again. You may want to try that.
  • Can one not manually enter apn settings? Maybe an automatic config goes wrong?
  • "And what if we already did setup our phones without the SIM? Should we do a hard reset and start over once we get the SIM?" The answer to this question is still unclear to me, after reading this article and thread. AT&T CS has been unable to fix this for me, and I am left wondering what my options are, short of returning the 950XL.
  • At least AT&T is giving windows phone somewhat of a chance. Less can be said for many of the other US carriers
  • Yeah although I find Cricket to be the only carrier to actually advertise windows phone.
  • Cricket is actually a subsidiary of AT&T
  • You guys seem to care a lot about visual voicemail, being from the UK I have no idea what this even is, but hey I guess I can't miss what I've never had!
  • It's like email but for voicemail. you can see a list of voicemails and play them directly, pause, and delete without having to call in to check.
  • Definitely a "nice to have" feature once you're used to it. Until I'd seen it I actually thought it was a feature that translated voice mail into a text-based message you could just read (hence the term 'visual'). But sadly, no.
  • There is a service that you can have your email transalted by computer or by a human  (Ymail). Paid services, while they do a have a free service it will not transcribe your email.. You can also use google voice for you voicemail. It will transcribe your email free. You get notifications. You have to use the web browser to actually listen to you messages. However, you can get a transcription of your voicemail in your email or as a text. This is all for "free".  
  • I never knew I wanted it until I got it
  • Yeah it is very funny how they still use voicemail and sms in the US. Looks like they didn't find out everything can be done via WhatsApp&co in a much richer way. They buy super expensive phone and use them as a 3310 . No offense intended! It's just to let you know most of the advanced world has moved forward :)
  • Because it doesn't really offer anything that we can't do, as far as voicemail and SMS are concerned. Voicemail and SMS aren't exactly flawed, people don't see a need to replace them. Not to mention getting people to physically download an App and set it up, including giving out their information to whoever they need to to use it is just more trouble than it's worth, if your not already using WhatsApp. Email and SMS just work, out of the gate. Just need to set a PIN for voicemail. Posted via the Note 4/Nexus 7 (2013)/Lumia 1020/Lumia 2520
  • Its good that in india we dont carrier dependant phones
    Just buy any phone and they should just work fine
  • Great article, I am eagerly awating my phone to be shipped and I will make sure to come back to this when I get it so I, hopefully, don't have any issues. I'm curious, you said you guys had no problems, did you already have an AT&T branded phones IMEI on your account before setting up your 950XL?
  • Yeah, my SIM was from the 1520 and I used it with Samsung and Apple too, so it was already in their system.
  • I had an att 1520, and used the same sim, also no issue with service.
  • A lot of those problems come from the fact that 950(XL) requires nanoSIM and most other Windows Phones work with microSIM so you need to get a new SIM card. And to activate it ATT asks you for IMEI of your new phone and that's where the problems start. I believe Daniel had already been using nanoSIM that's why he didn't experience any of those problems. I personally come from Lumia 920/635 combo and they both were micro. I'm not sure which of older WP's use nano. But if you have iphone or a newer Galaxy you should be good with just putting your card into 950.
  • I'm on T-Mobile coming from the 925. So I have the same problem with the SIM size. But when I called in, they just said they would mail me the card overnight. Should come in today and hoping it will be dead simple to activate.
  • You'll be fine either way. I've mentioned it in a few other posts here but if you turn the phone on before putting the sim in just make sure you got to settings- cellular and sim and turn the data connection on after you put the sim in. The phone will likely ask you to reboot once it picks up the network and at this point it will put in the correct APN for LTE and MMS on TMobile. Instead of waiting overnight I'd just go to a TMO store today and get one. That's what I did and it only took about 5 mins.
  • Or you could just take a box cutter to the sim.... I've done this before
  • I am transitioning from an L920 to L950XL. I walked into the AT&T store with my L920 and asked to have the number transferred from a microSIM to nanoSIM. Total time in store: 4 minutes, no questions asked. I consider myself fortunate.
  • My ATT store just clipped my microsim to a nanosim with a hand tool. Told me they don't issue new SIMs just for that anymore. Didn't even need to look up my account when switching from L635 to L1520.3.
  • You ARE lucky.  I did the exact same thing with mine and I have NO cell data, NO MMS, NO group texting and NO voice mail, even regular voice mail. seriously ticked off right now.
  • Take  look at your APN settings. I had the same issue with my unlocked 830. If you have AT&T, try this;!/wireless/KM1062162 or use their online chat and tell them you have a different phone (give them an IMEI from either something old that you have or like others say, get the IMEI off a floor model) and tell them your problem and you notice the APN setting are not filled in correctly.  
  • I setup my phone on WiFi, then put my sim in, it came up as LTE, but the phone had cellular data off by default.
  • Same here, it didn't start showing the word LTE until I traveled with it. Now, if they can only improve the battery life or sell an extra battery with charger :-(
  • Let's get AT&T working on wifi calling for the 950 models please.
  • This is clearly very valuable info.
  • Does the screen has a limited numbers of characters. What I see as my provider is ROGERS L. Is it LTE but it's limited by character's lenght?
  • No LTE shows up as a separate status icon in the status bar its on the left right beside the signal meter
    Also it shows up only when cellular data is on
    It also could show E or 3G or H+ or 4G Posted via the Windows Central App for Android
  • I also see the same thing.  I also noticed that it seems to spend much more time in the H+ and G services.   It also seems that the speedtests are running a lot slower than they did on my 920.  Have you noticed any thing like that? Once I get a micro sim back into my 920 I'll try a side by side speed test. I did set mine up on wifi before I had a microSIM.
  • mine shows the exact same thing....
  • I was going to pick up my pre order 950XL today but no visual voicemail may be a deal breaker. Hopefully this can get figured out.
  • It's not a deal breaker. There are alternatives, and with enough prodding at&t might do something.
  • Dear editor: there is a difference between "setup" and "set up". Check it out.
  • pass
  • Who are the people paying full price on this phone? Is there a trick I'm unaware of or do they just not concern themselves with price? If there's a trick or deal please do tell!
  • The trick is to work hard and save money, then buy.
  • Haha, that doesn't work for me. I need a good deal when I buy stuff. I never pay full price for anything. It's just the way I am.
  • Sorry but this is the future of phone buying experience Posted via the Windows Central App for Android
  • Lol, for you maybe. Not for me. I can patiently wait for the software to improve and the price to fall. Until then I am happy with my 1020.
  • Are you a student? 10% at the Microsoft Store. 5% discount if you are Military. 
  • 950XL is still cheaper than prior flagship phones. Just used to be more often embedded in monthly fees and/or early termination fees in the past. WinMo HTC Touch Pro was $700. Lumia 1520 MSRP was at least $1000. That said, I'm also amazed by how otherwise-frugal people justify new flagship phones every year or two (myself included). Spend your money where you spend your time, I guess.
  • So lying about the IMEI gets you on their network? Why don't the thieves just 'phone in a fake IMEI' and use your phone as their own? How exactly is your phone correctly identified on the ATT network after this?
  • The entire reason I know this works is because a manager at an AT&T store suggested I do this years ago (imported Nexus S). He walked over to a display model, got an LTE IMEI off of a branded phone, put it on my account and it worked. That was enough of an endorsement for me. AT&T created this monster, so it's not "stealing" in any way. It doesn't tie the equipment to your line, just flips the switch in AT&T's systems to enable LTE. Not a sophisticated solution, but until AT&T pulls their head out with unlocked devices, it's the solution they are requiring themselves.
  • The SIM card.
  • I have lte right now but I drop to 4G alot more than I did on my 1520
  • Is this the same on TMobile? MMS appears half working for me.
  • Go to settings-cellular and sim and make sure your data connection is turned on. Once you turn it on the phone should ask you to restart(possibly a couple times) so it can auto fill in the APN settings. Once the TMO APNs are in you should be fine on LTE and fine with MMS.
  • No issues here. Went from 1020 to the 950xl.
  • Was on the phone over 60 minutes. After 30 minutes they "explained" that my phone was not LTE compatible and transferred me to tech support. For another 30 minutes, we discussed that unless the phone is branded for AT&T, it will not work. We agreed to disagree, and I had him register the new nano-sim I got from the retail AT&T store to my old Lumia 920. I lost my voicemails, no visual yet, and still no LTE.     Edit. I created a manual APN based on these settings, then i got LTE.!/wireless/KB424489?source=red...
  • Peter, would you please expand on how you had entered the APN? The ATT directions are not clear to me.
  • Here are screenshots of where it is and what to do
  • From the "Get started Lumia 950 XL Dual SIM" guide that comes in the box: "2
    "Insert the SIM and memory card
    "Your SIM card has an effect on important settings. Insert the SIM card before turning the phone on." I did that and LTE worked fine. I guess others got started a little too quickly?
  • I would say they probably didn't read the manual as not many people do lol.
  • No, it has to do with the phone you used the previous SIM card on. If your previous SIM was set up for LTE and visual voicemail, you're home-free on the 950 XL. If, like me, you had to get a new SIM card, they recognize the 950 XL IMEI as a generic/dumbphone not capable of LTE nor Visual Voicemail.
  • As a fellow RTFM type, I hope I'd have been so circumspect to do so, but fortunately, my device is sitting at UPS waiting for me to pick up so I am tuned into these issues.  As a convert (to AT&T) from Vz, I am interested, was your SIM brand new or did it come out of an existing AT&T LTE device?
  • Daniel, does WiFi calling work on the 950xl?
  • For the most part just manually dial in your voicemail, after you got connected to your voicemail, listen to one voicemail then hang up the phone , after a few moment you start seeing the virtual voicemail prompt you to set up.
  • Didn't like on xl
  • This is the exact reason I am not with AT&T....
  • Would this be the same for other phones or just these? Im about to buy a 640 for someone but I want to set it up before putting in the SIM
  • As long as the 640 (or any phone) has an AT&T logo on it, you're good to go.
  • But would it still cause the problem that is talked about in the article? (Issue #1)
  • No
  • I did the setup before sim thing. LTE works but I had to add an apn for mms.
  • what is an apn for mms and how do you add it?
  • Check the 950XL forum, I posted it last night.
  • I can't get VVM working on my launch day AT&T 950. I have a feeling the sales rep didn't do something right, as when we set the phone up we were on the stores wi fi. When I got to my car, I had no cellular data, etc. I rebooted my phone and it just worked since, except for VVM. Tried calling my VM, etc.
  • This is so wrong. Forcing customers to buy their branded or supported devices.
  • Agreed!! Got mine and my parent's 950XsL finally running LTE but everytime the support rep I called said they were going to try something else to get LTE working she added "You know, to get the full AT&T experience you should buy an AT&T branded phone." I kept saying, "Yes ma'am, but my elderly parents wanted the phone with the larger screen and AT&T declined to offer it."  To which she said, "We have a very large selection of phones."  To which I replied, "Yes ma'am/" ;)  
  • You can also find your IMEI by pressing *#06# on your phone dialler.
  • Was coming to say the same thing! :)
  • Omg Microsoft play the game with 950 users
  • There may be a very simple solution to issue #1. I bought an unlocked 950 last night for use on Tmobile. I wasn't able to pick up a nano sim until this morning and went through the setup process last night without a SIM. After inserting the SIM I was not getting an LTE connection. Turns out when you don't set up the phone with a sim the phone defaults the data connection setting to 'off'. To fix this simply go to settings-cellular+sim- and turn the connection on. It should auto pickup the correct APNs for data and MMS after doing this. Hope this helps.
  • Wow all that work just to get what should be automatically activated!!!! I had a problem with my phone from O2 where I couldn't use a USA sim in it where it is meant to be Unlocked because I bought it via Carphone Warehouse but I had to contact O2 to ask then to unlock it, they said it was a Windows Phone thing, I don't know how true it was, but I found that surprising, hopefully won't have that problem with 950 XL since it will be bought unlocked from Microsoft store!!!!