If you've just updated your iPhone to iOS 26 and find that iMessage has stalled, you're not alone. Many users are seeing an activation failed message, seeing messages appear green, or not even getting delivered; check out How to send messages with your iPhoneIn many cases, the root of the problem is a Inactive SIM or a duplicate eSIM that interferes with the number's registration in iMessage.
Apple has acknowledged this issue and has detailed how to detect and resolve it without any problems. Among other things, you'll notice that messages aren't being sent, appear as SMS or RCS, or are sent from an email instead of your number. Everything points to a line conflict, and luckily, it can be resolved by following these steps: A few simple checks and removal of the inactive SIM where appropriate.
Clear signs that iMessage is not working properly after the update
The most obvious clue is that messages aren't going out and you get a 'Not delivered' message. Sometimes, even if you have Wi-Fi or data, the conversation changes from blue to green and texts are sent as SMS or RCS instead of iMessage, which indicates that the number is not properly activated on the service.
Another curious indicator is that your messages are suddenly being sent from an email address instead of your phone. This rerouting usually occurs when the system detects a conflict with the line. You may also notice a spinning icon next to the number in 'Send & Receive'; it means iMessage is trying to verify your number, and sometimes it gets stuck if there is an inactive SIM in between.
If you go to Settings and, under Messages > Send & Receive, see your number repeated or duplicated, this is a sign that the system is keeping a previous line. In some cases, the same number appears twice because there is a Old eSIM or a physical SIM that the iPhone no longer uses but is still saved in the settings.
By the way, Apple has published specific guides on this issue and recommends patience if you see the verification status spinning; however, when there is a line conflict, waiting is not enough and it is necessary remove the inactive SIM so that everything returns to its place.
Why it happens: Inactive SIM or duplicate eSIM blocks activation
This isn't a generic iOS 26 bug, but rather a problem with the combined SIM and eSIM functionality on some iPhones. When the system keeps an inactive line with the same number as the current one, iMessage gets tangled up and fails to correctly associate the phone number. The result: messages aren't activated, they become SMS or RCS, and occasionally they come from your email in iMessage to try to save the day.
Apple itself explains that if you have two cards (physical or eSIM) that share a number and one is no longer in use, that old line may block activation. The most visible symptom is a duplicate number in 'Send & Receive' or forced sending as a green SMS. As soon as you delete the extra line, iMessage returns to link your number no complaints.
Important: Some users have reported that even after waiting 24 hours, the service would not activate. Waiting may work when there is a server delay or verification is in progress, but in the case of SIM conflicts, the determining factor is remove the inactive line.
Apple's recommended solution: remove the inactive SIM and reactivate iMessage
This is the procedure Apple suggests when you detect duplicates or an old stored line. First, check if your carrier uses eSIM and if you no longer use one of your lines. The flow proposed by Apple is simple and usually resolves the problem immediately because it forces the system to link the correct number with iMessage.
- Open Settings and go to 'Cellular' or 'Mobile Data'. Locate your active lines.
- If two SIM cards with the same number appear, identify which one isn't active. If it's a physical SIM card, remove it from the iPhone; if it's an eSIM card, tap "Remove eSIM" to remove it. Avoid keeping duplicate lines.
- Go back to Settings, go to 'Apps' (if your system displays that path), and then 'Messages'. On most iPhones, you can also go directly to Settings > Messages. Both routes are valid.
- Tap 'Send & Receive' and, when prompted, select your phone number to activate iMessage. Check that no email is coming out as default.
If this doesn't resolve the issue, Apple suggests trying additional steps: turning off iMessage and FaceTime, restarting your iPhone, and then turning them back on; signing in online to complete the iMessage/FaceTime activation; or temporarily using a mail address as an identifier in Messages and FaceTime while verification is completed.
It's also a good idea to check the service status on Apple's website in case there are any specific issues. If everything is green and your iPhone still won't activate, it's most likely because the lock is from local configuration and not from the server.
Diagnostic Guide and Additional Fixes That Work
In addition to removing the inactive SIM, there are a series of checks that usually unlock activation. They are simple, don't require any unusual tools, and, combined, cover almost all common scenarios when iMessage crashes after iOS 26.
- Check your connection: Make sure you have stable Wi-Fi or mobile data. A quick switch to airplane mode and back can help renew your session. Without strong connectivity, iMessage won't activate..
- Automatic date and time: Go to Settings > General > Date & Time and select 'Adjust Automatically.' If it's already set, turn it off and back on. An incorrect time blocks verification.
- Check 'Send & Receive': Settings > Messages > Send & Receive. Make sure your number is listed and selected, not just your email. Prevents the default email from being set.
- Sign out and back in with your Apple ID: In Settings > Messages > Send & Receive, tap your Apple ID, sign out, sign back in, and sign back in. This renews the tokens with Apple servers.
- Update your carrier settings: Settings > General > Info. If an update notice appears from the operator, accept it. Network settings influence activation.
- Reset network settings: Settings > General > Transfer or reset > Reset > Reset network settings. Then reconnect to your Wi-Fi. It does not erase your data, only saved networks and keys.
- Activate iMessage/FaceTime online: Apple offers a web-based activation process; you can check out the wizard at apple.co/IMFT-mac. Useful if the local process gets stuck.
An important note: If you see a spinning icon next to the number in 'Send & Receive,' the system is verifying. Give it a reasonable amount of time. Apple sometimes suggests waiting up to 24 hours, although if you have a duplicate or inactive line, waiting is no substitute for removing the problematic SIM.
Also keep in mind that some websites include ads for accessories (cases or chargers). These are irrelevant to the issue and aren't part of the solution. Focus on the checks above and, above all, on the management of your lines.
Real experiences: what other users have tried
There are cases where, after updating to iOS 26, users have tried absolutely everything: turning off iMessage and FaceTime, soft and force restarts with both disabled, removing and inserting the physical SIM, signing out and signing into iCloud, and even initiating a request for online activation. Even so, the service wouldn't activate, and Apple recommended waiting 24 hours.
In that specific scenario, what really unblocked the problem was detecting that the device had an invalid eSIM with the same number as the active line. Upon removing it from Settings > Cellular/Mobile Data, and then dialing the number again in Settings > Messages > Send & Receive, the iPhone reactivated iMessage immediately.
Practical conclusion: If you've already reset, switched between iMessage/FaceTime, and checked your Apple ID, don't obsess about doing it again. Invest that time in a thorough review of the mobile lines section and remove any inactive or duplicate eSIM profile.
Information note: Several public guides and help notes have recently been updated with this behavior. Official sources have even indicated the publication date of October 15, 2025, in some documents, reflecting that Apple is aware and has been adjusting its instructions on iMessage.
What else does iOS 26 bring besides this iMessage tweak?
Beyond the iMessage scare on certain devices, iOS 26 stands out for its new visual language, called Liquid Glass. This design approach emulates the properties of glass, with real-time reflections and refractions of the environment, so that the content gains more presence on the screen. The style extends across iOS, iPadOS, macOS, watchOS, and tvOS, so that the visual experience is consistent throughout the ecosystem.
Navigation has also been revamped. You'll see controls with softer curves and rounded corners reminiscent of current hardware, integrating better with recent iPhones and other products. The goal is to make the interface more user-friendly. intuitive and comfortable, with a modern aesthetic that matches the physical design of the devices.
In terms of features, Apple Intelligence is driving practical new features: real-time translation of calls and messages, a custom emoji generator (Genmoji), and automatic text summaries with reminder creation from email. All of this is designed to reduce friction and save time on repetitive tasks.
Native apps have received a few tweaks. Messages gains in-chat polls and the ability to customize conversation backgrounds; Phone unifies favorites, recents, and voicemail into a single view; and Safari adopts the new style with a more translucent address bar. There are also improvements to performance, battery life and accessibility that are noticeable on a daily basis.
IOS 26 Compatible iPhone Models
If you're wondering if your iPhone supports iOS 26, here's the list of models listed in the recently released guides. Always check with Apple's website if you need a second validation, but for reference purposes, the list includes all these devices with Pro and mini variants where appropriate.
- iPhone 11, 11 Pro and 11 Pro Max
- iPhone SE (2st generation)
- iPhone 12, 12 mini, 12 Pro and 12 Pro Max
- iPhone 13, 13 mini, 13 Pro and 13 Pro Max
- iPhone SE (3st generation)
- iPhone 14, 14 Plus, 14 Pro and 14 Pro Max
- iPhone 15, 15 Plus, 15 Pro and 15 Pro Max
- iPhone 16, 16 Plus, 16 Pro, 16 Pro Max and 16e
- iPhone 17, iPhone Air, iPhone 17 Pro and 17 Pro Max
Tips to avoid the problem in future updates
Before installing a major update, back up your data to iCloud or a computer. That way, if something goes wrong, you can revert without losing anything. It's also a good idea to check Settings > Cellular/Mobile Data to see if there are any old eSIMs you're no longer using. If there are, remove them before updating so that do not drag a configuration problematic to the new version.
If you travel frequently or alternate personal and work lines, label your lines in iOS to quickly identify which is which. And if you change carriers, check with them to see if your carrier settings need updating in Settings > General > About. This seemingly minor detail can make a difference. iMessage activation.
Finally, once you've finished updating, go to Settings > Messages and verify that your number is selected under 'Send & Receive'. Taking a minute to check this will prevent surprises with messages coming from email or conversations that appear in green.
Advanced options and usage warnings
If none of the above works and you're still stuck with iMessage, there are system repair utilities that promise to fix iOS errors without erasing your data. Tools like ReiBoot offer standard repair modes and upgrade/downgrade options. Use these as a last resort, understanding that they're third-party and that it's always best to exhaust Apple's official steps first. In some cases, downgrading to a previous stable version is even considered if there are multiple glitches in a row, something that should be done with caution. caution and backup.
It's important to note that Apple has released rapid revisions like iOS 26.0.1 to iron out initial details and has been fine-tuning its iMessage instructions. Most activation issues are resolved with line management and network/date verification, so don't rush into aggressive solutions unless strictly necessary. Less is more when the problem is a configuration problem.
Quick questions that often arise
Not receiving message alerts? Check that you don't have Focus mode active and go to Settings > Notifications > Messages to confirm that alerts, sounds, and banners are enabled. Often it's a notification setting, not a notification. iMessage failure.
Not hearing vibration when receiving messages? Check in Settings > Sounds & Haptics that 'Vibrate on Ring' and 'Vibrate on Silent' are turned on. Also, make sure the side mute switch is not activated. If haptic feedback is behaving strangely after updating to iOS 26, a restart and checking these toggles usually fixes this. return the vibration to normal.
When is it a good idea to wait 24 hours? Primarily when you see the verification icon in 'Send and Receive' and there are no duplicate lines. If you detect an old eSIM or a duplicate number, waiting won't resolve the conflict: the next best thing is to wait. remove the inactive SIM and reactivate iMessage with your correct number.
After all of the above, the picture is pretty clear: when iMessage is stuck on iOS 26, it's most likely due to an old line interfering. The winning combination is to remove the inactive SIM, confirm the number in 'Send & Receive', and finish with network, date/time, and carrier settings checks. In the meantime, you can continue using email in iMessage if you need to, but as soon as the number is properly associated, the issues return. blue bubbles and immediate delivery no more stories.
