No signal on iPhone 15 after iOS 26 update – SIM works in other phone

[Watso20]

Hi all,

Since updating my iPhone 15 to iOS 26, I haven’t been able to get any signal on Three. I can’t make or receive calls or texts.

Here’s what I’ve tested so far:

• My Three SIM works fine in another phone.

• A giffgaff SIM works fine in my iPhone 15.

• So it seems specific to my iPhone + Three combination.

• I’ve already tried:

  • Restarting the phone

  • Airplane Mode on/off

  • Removing/reinserting the SIM

  • Checking for carrier settings updates (nothing popped up, and my About screen shows carrier version Three 65.0)

  • Changing “Voice & Data” between 5G Auto / 5G On / 4G

  • Resetting network settings

Unfortunately, none of this has fixed it.

Has anyone else on Three had similar problems with iPhone 15 and iOS 26? And if so, did you find a fix?

Thanks in advance for any advice.

[Steve1590]

Yes I have exactly the same issue and my wife and daughter too. So frustrating 

[JonathanB]

Hi @Watso20,

I'm sorry to hear you've been experiencing issues with picking up any service since this software update. I haven't seen any other issues reported matching this description. Did you manage to resolve this in the meantime?

If not everything else you've tried so far sounds like the right sort of troubleshooting. It doesn't seem like this could be an account issue as it's only triggering with the combination of the specific iPhone and your SIM.

If you've had the SIM for a while now and used it with other phones, there may be some minor damage or fault that means the SIM isn't reading properly in the iPhone. It's very rare, but I've once seen heat damage cause a SIM to warp a bit, and read in some phones but not others.

So it may be worth replacing your SIM here, the quickest way to do this would be to pop into a Three store with photo ID. The replacement SIM will usually be active before you leave the shop.

If that doesn't solve it, I think you may wish to either factory reset the iPhone, or take advice from Apple, as it may be a software or hardware issue with the phone.

Thanks,
Jonathan