iMessage Activation - iPhone 17/iOS26

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Level 1

7 points

iMessage Activation - iPhone 17/iOS26

I am currently unable to use iMessage/FaceTime with my phone number, after transferring across to my new iPhone 17.

I keep getting the same generic error message (An error occurred during activation. Please try again), when toggling iMessage/FaceTime, or attempting to switch to using my phone number as the primary.

Some context -

this has been an issue for ~4 days now
I moved from an iPhone 14 (iOS 18.7) to an iPhone 17 (iOS26.0)
The automatic transfer moved across all the usual app data, phone number (eSIM from O2) successfully
I can send/receive regular SMS/calls as usual
I have contacted my network provider (O2) and they could not resolve the issue on their end (or didn’t know how to)
I have followed the troubleshooting steps in this article already: If you can’t turn on or sign in to iMessage or FaceTime on your iPhone – Apple Support (UK)
I have also tried signing out/back in to my Apple ID, to no avail
iMessage/FaceTime works perfectly fine when using my iCloud email, but refuses to activate my phone number
This has always worked fine on my previous device, and I still have my conversations that use my phone number. However if I respond, it appears to the recipient as coming from my email address instead (same with FaceTime calls). If someone tries to respond to my existing conversation, it gives them an error message (phone number uncontactable) and sends as an SMS instead

Any support/guidance would be much appreciated!

iPhone 17, iOS 26

Posted on Sep 29, 2025 2:49 AM

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Answer 1

Top-ranking reply

moondoggie64

Level 1

0 points

Oct 21, 2025 11:01 AM in response to EdenLizard

I had the same issue upgrading from an iPhone 16 Pro Max to a 17 Pro Max (both running iOS 26) and while there were no issues originally activating the new device from Verizon, I still had the iMessage activation error. The fix for me was to delete the eSim and then reactivate it with a new eSim from Verizon. I did of from the Verizon portal, didn't need to call in.

All fixed now.

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Answer 2

TSCNEO

Level 1

14 points

Sep 30, 2025 7:01 AM in response to EdenLizard

I’m experiencing the exact same issue.

Previous device: iPhone 16 Pro Max (iOS 26)

Current device: iPhone 17 (iOS 26.0.1)

Carrier: Movistar (Spain)

Just like you, I can use SMS and calls without any problem, but iMessage/FaceTime refuses to activate with my phone number. I’ve already tried all the recommended troubleshooting steps (including signing out/in of Apple ID, resetting network settings, etc.), and my carrier confirmed that there are no restrictions on my line.

It seems to be happening specifically with iOS 26.x.

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Answer 3

Nov 17, 2025 2:17 AM in response to EdenLizard

I have been facing this issue since 2nd nov. I did all the troubleshooting through apple support and check with my carrier. Everything is fine but the issue still not solved.

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