Welcome to the O2 Community

Has your question already been answered? See the community FAQ's

How-to Guides

iPhone XS/XS Max/XR Dual Sim Guide

by on ‎04-12-2018 16:12 - last edited on ‎27-09-2019 10:33 by (70,494 Views)



Hi there -

  • If you've landed on this guide in search for information related to the new Apple devices (iPhone 11, 11 Pro & Pro Max), head over here to our Apple megathread for more information. Smiley Happy
  • If you're looking for info on eSIM, see latest updates here!



As someone running a dual SIM setup on my iPhone XS Max I thought I’d provide a handy guide for anyone setting up this service.




In order to run a dual sim setup you need the following


iPhone XS/XS Max/XR - ideally unlocked unless you want to run dual lines on EE (which would be odd on an O2 user forum) as the eSIM will lock to the same network as the nano sim tray


A line on EE - iPhone’s dual sim setup at the time of writing this guide requires the use of an embedded eSIM and the only network to support eSIM at the time of writing is EE


A line on a second network such as O2




For the line that you are running on the eSIM you will need to perform a SIM swap over to an eSIM. This can be done either by calling EE customer services or visiting a store


Full details on the process can be found at https://ee.co.uk/help/help-new/getting-started-and-upgrading/using-your-phone-features/how-do-i-use-...


Once you have moved the EE line to eSIM you can remove your EE sim and insert a sim for O2 (or any other network) to use as your second line. Once you do this the iPhone will detect there are two sims and guide you through a setup process to decide which line is your primary line and which line is your secondary one. It will also ask you what line you want to use for mobile data and iMessage. Only one line can be used for iMessage which is currently an iOS limitation and may not suit people on dual handset setups where you can have two numbers for iMessage. 


These settings are not set in stone and you can change them as and when you need (I often change my mobile data network based on signal strength for example)




I ran into the following issues when I moved to a dual sim setup (most of these issues only apply to the EE line) 


1. Issues sending SMS messages on both lines - this is down to an issue in iOS which prevents you from sending a message to an existing message thread once you move to an eSIM. The issue is solved by either deleting the message thread or waiting for the other person to send an SMS message to you which resolves the issue. The issue may have been resolved in iOS releases that have come out since 12.1

2. BT sport app not working - this is down to a bug in the BT sport app where it doesn’t detect the eSIM on EE. At the moment EE are fixing it by adding a free trial of casting to the accounts of those with the issue which does fix it at least for 3 months

3. Voicemail not working - Visual voicemail will work on both lines once you have it set up right however moving to eSIM completely disabled my voicemail on my EE line. Texting VM ON to 150 on the EE line resolved this. You also need to make sure your O2 line is on an iPhone tariff for visual voicemail to work on that


Hopefully all the above helps for anyone else wanting to run a dual sim setup with EE/O2 on the latest iPhones


If anyone has any questions or issues in setting it up I’m happy to help out where I can




on ‎04-12-2018 16:35
Nice one Dave Smiley Happy
on ‎04-12-2018 16:57

Shame this doesn't apply to O2 phones and an EE SIM is needed. Maybe 2019 if O2 take their fingers out!

on ‎04-12-2018 17:06

@jonsie wrote:

Shame this doesn't apply to O2 phones and an EE SIM is needed. Maybe 2019 if O2 take their fingers out!

Yeah at the moment there is no getting around the fact that the line on the eSIM has to be on EE. I suspect Vodafone may not be too far behind as they have eSIM technology in place for the Apple Watch now. God knows how long it will take the other networks to catch up but I suspect eSIM isn’t going anywhere and the networks will have to embrace it sooner or later


I run the dual sim setup with EE on my eSIM and an O2 Nano SIM in the SIM tray which is working fine for me barring the teething issues I mentioned in the guide

on ‎04-12-2018 17:09

There are good workarounds described @davethorp and thanks for those tips.

on ‎04-12-2018 18:46

@davethorp I thought all o2 phones sold now were unlocked etc not tried a non o2 sim in my phone yet 

on ‎04-12-2018 18:49

@adamtemp64 wrote:

@davethorp I thought all o2 phones sold now were unlocked etc not tried a non o2 sim in my phone yet 

They may well be. My XS Max came from Sky who unlock their phones by default and O2 may well do the same or at least have done with my tablets


As long as the phone is unlocked a dual sim setup is possible but only with the 2nd line being on EE for the time being as my setup is

by Community Manager
on ‎10-12-2018 11:12

Great guide @davethorp! Thanks for putting this together. smiley

on ‎10-12-2018 11:51

Great little guide @davethorp. Very useful

on ‎18-02-2019 16:26
Hi there. Any idea if I can use an Australian sim as the fixed sim and then O2 under esim on the one handset? Desperately trying to stop using two handsets!!!!
on ‎18-02-2019 16:28
Thanks so much for any assistance!
on ‎30-04-2019 15:43

Sorry for the long delay in replying @DPL . Only just checked back in this thread. If anyone else has any further questions please tag me by typing @ and then my username straight after so I see the question


O2 do not support eSIM so the setup you propose would not work. As far as UK networks go the eSIM at the moment has to be on EE. There’s no getting around this regardless of if the phone is unlocked or not as EE are the only UK network to support eSIM at this time, although I suspect Vodafone wont be too far behind for reasons I’ve already covered


The nano sim tray can be any network UK or otherwise so yeah you could run a setup with a UK network on the eSIM and a foreign network on the nano sim but not on O2 as you proposed

on ‎01-07-2019 12:13

Just to update this guide slightly


The guide mentions that iMessage is only possible on one line. From iOS 13 which is currently in Beta for a release in September though a public beta version is available iMessage is possible on both lines in a dual sim setup

‎03-09-2019 03:16 - edited ‎03-09-2019 03:25
on ‎28-10-2019 21:52
@davethorpdoes this mean you can receive calls from two different networks with out changing any settings?
‎29-10-2019 12:23 - edited ‎29-10-2019 12:28

@davethorp  .  Thanks for the guide.

You possibly know this but things have moved on since you wrote it and you can now get an e-sim from O2.


I am using an O2 e-sim for my secondary line on my iPhone 11 Pro Max. It all works fine except that I can not get any voicemail notifications/alerts working on the e-sim.

on ‎29-10-2019 16:15



Yeah this guide was created last year when EE were the exclusive network offering eSIM in the UK. O2 have now joined the party and so you can run setups with O2 on the eSIM now like you are doing


I had voicemail issues on EE when I first switched to eSIM with them. They were solved by turning voicemail off and back on again. It's possible something similar might solve your issue on O2

on ‎15-06-2020 18:53

Getting on for a year later and I have the same issue - eSIM as a secondary on iPhone 11 Pro Max.  Everything okay apart from visial voicemail - or voicemail of any sort to be honest. One of their second line support staff told me it was an issue with using visual voicemail on an eSim and that they're working with Apple to resolve the it.  When I used EE as a secondary eSIM in the same phone visual voicemail worked fine.

‎15-06-2020 20:30 - edited ‎15-06-2020 20:33

@timjd Here is my story https://community.o2.co.uk/t5/Pay-Monthly/No-notification-of-new-voicemail/td-p/1267249


Basically I have never been able to get voicemail notifications to work on eSim 2nd line, so I got O2 to remove the "IPhone bolton" and I use traditional style vmail with SMS notification.  The iPhone bolton is O2 speak for visual voicemail.

‎16-06-2020 12:50 - edited ‎16-06-2020 12:51

O2 called me earlier on today to give me an update on this.  They told me that the fix would be included in iOS 14.  In the meantime they asked me to enable iMessage on my eSIM (I'd got that off until I port my mobile number).  That fixed it for me, visual voicemail is working exactly as I'd expect Smiley Happy  They also told me that, for some people whi have iMessage enabled already, turning it off and back on again works.

on ‎16-06-2020 12:54

Thanks for that info @timjd wink

on ‎18-09-2020 19:17

Hi Guys,

I've been having this issue since I owned my iPhone XR. 

It would appear that if you use a US eSIM (mine is T-Mobile) and a physical SIM (mine is O2) together that the data connection on either SIM will not be:

  1. strong
  2. consistent
  3. fast

I have had numerous dropped signal, slow web page, no web page, no video, data errors etc over the last year and a bit when not connected to WiFi. 

Recently a senior tech at O2 texted me to say that the iPhone XR was not Dual SIM compatible on the O2 network. 

I have sincerely tried everything: complete wipe and restore, reset network settings, install new physical SIM, install second new physical SIM, reinstall eSIM, install physical SIM only, install eSIM only, plus much more. 

The only thing that works is turning off the eSIM completely, then there is no problem. 

I believe that Apple and O2 know that this is an issue and that perhaps those of us who purchased our iPhone XR specifically to utlise the dual SIM capability have been mislead by Apple in the first instance. 

Please let me know if anyone else has had any similar experience.

Many thanks,


on ‎19-09-2020 18:07

I've had an update on this from Apple and they are investigating and escalating this issue, but they did say that there is a possiblity that O2's provided iPhone XR network firmware does not support Dual SIM compatibility. 

on ‎19-09-2020 18:36

There is no network firmware for iPhones, only carrier profiles and I'm sure if there was an issue with dual sim use on any O2 iPhone, the forum would be full of complaints, but it's not, so it seems you have an isolated issue with either your sim or phone.

on ‎19-09-2020 19:50
Carrier profiles. Thank you for the correct terminology. It is still possible that the O2 carrier profile’s Dual SIM capability is not compatible with the iPhone XR. A point which O2 have already admitted to me in writing.
With regard to prevalence of the issue, maybe I am one of the relatively few people who use T-Mobile US eSIM with an O2 physical SIM and live in a rural location.
on ‎19-09-2020 20:05

Probably not many that use a US Esim which I can agree would quite likely cause issues, but that doesn't mean that it's a specific O2 issue.

As you are the only one reporting any problems, I refer back to my previous statement.

on ‎08-11-2020 12:49
I don’t know if anyone’s struggling with using dual sim with iPhone where one number goes to no service when you’re using another. Apple advertise that this is the case on their website and it really affected my business where I was missing loads of calls.

I tried call forwarding but that didn’t work.

I asked an apple representative who told me there is no work around so I began to try different methods as I wasn’t going to accept that in 21st century.


My fix around is switch both 02 sims to WiFi calling. Problem solved: both numbers stay in service even when you use the other.

I can now receive calls on both lines even when on a call.

Hope that helps
on ‎14-12-2020 08:52
Hi Guys,
I’m still having this issue even after apple changed the phone.
There is either a problem with the carrier firmware (O2) or the phone hardware (Apple), but the fact is the iPhone XR is not Dual SIM Compatible on the O2 Network. It’s fine if you’re in an area with a very strong signal but the moment you go down to three bars you get dropped connection, dropped calls, slow data, multiple socket connection failures etc.
It could be specific to having a US eSIM (T- Mobile) and an UK physical SIM (O2), but it is definitely a thing.
on ‎14-12-2020 08:55
Also. O2 are now trying to close the case even though I’ve phoned them to keep it open.