Since the rollout of iOS 26 last month, a growing number of iPhone users have reported that their phone numbers won’t activate iMessage, disrupting what many see as a core part of Apple’s messaging experience. The issue has sparked frustration across online forums and tech news sites. In response, Apple has now published an official fix and support guidance to resolve the bug, but the patch may not be seamless for everyone.
The iMessage Activation Bug Unfolds
Shortly after the iOS 26 update started reaching users in late September, complaints began to surface across Apple support communities and social media. Users described that their iMessage attempts would fail, often showing a “Not Delivered” message. Some found their messages switching from Apple’s signature blue bubble to green — indicating they had reverted to SMS/RCS — or being sent from an email address instead of their phone number.
Particularly, the issue tends to arise when a user has two SIMs (or eSIMs) on the same device linked to the same phone number, but one is inactive. Apple clarifies that the system’s logic may misinterpret the presence of an inactive SIM as a conflict, blocking activation of iMessage properly.
In Apple’s official guidance, the symptoms to watch for include:
- iMessages failing with a “Not Delivered” alert
- Messages defaulting to SMS/RCS (green bubbles)
- Use of an email address instead of a phone number
- The same phone number appears twice under Settings → Messages → Send & Receive
Forums suggest the issue has affected users across iPhone models — from iPhone 13 to iPhone 17 — especially those who upgraded devices or migrated their eSIMs.
Apple’s Official Fix: Remove the Inactive SIM
In its new support document, Apple recommends a clear sequence to resolve the glitch:
- Open Settings → Cellular (Mobile Data)
- If two SIMs are listed with the same number, identify the one that is no longer active
- If the inactive SIM is physical, remove the SIM card; if it’s an eSIM, use the “Delete eSIM” option
- Return to Settings → Messages → Send & Receive
- Tap the phone number listed to re-activate iMessage with your number
Once the inactive SIM is removed, activation should proceed. However, Apple notes that in some cases, users may have to wait up to 24 hours for activation to complete.
Should the fix fail, Apple suggests reaching out to official support, as more complex issues or network-level restrictions may be involved.
Real Users, Real Struggles
On Apple’s official forums, multiple users have detailed their frustrations. A common post states:
“Since updating to iOS 26, my phone number won’t register with iMessage. Tried everything — restart, toggling settings, logging in/out — nothing works.”
Another user transitioning to a new iPhone 17 found that despite migrating all data and the eSIM, iMessage would only activate via email, not the phone number.
Meanwhile, Reddit users echoed similar narratives: attempts to deactivate and re-enable iMessage or FaceTime, resetting network settings, and SIM removals often yielded no success. Some reported that Apple Support acknowledged the issue but had not yet provided an individualized solution.
These firsthand accounts underscore that while Apple’s fix may work for many, not every configuration is easily resolved.
Why the Bug Matters
iMessage is deeply ingrained in the Apple ecosystem. Beyond just being a messaging tool, it offers encrypted communication, seamless syncing across devices, and integration with features like Apple Watch. Losing access due to a glitch undermines key differentiators in Apple’s environment.
The green-bubble shift (SMS/RCS fallback) not only affects functionality but can also impact perception, especially in markets where the blue bubble is culturally iconic. Additionally, sending from an email address rather than a phone number can cause confusion in contact lists and message replies.
Moreover, this issue arrives amid a broader backdrop of iOS 26 having multiple early-stage bugs — from calendar search malfunctions to unexpected behavior in new features. The iMessage bug is arguably one of the more critical because it touches a fundamental part of daily communication.
Caveats & What to Do If the Fix Doesn’t Work
While Apple’s inactive SIM removal method addresses the majority of cases, several complications may prevent a clean resolution:
- Network carrier restrictions: Some carriers may block certain activation signals or frameworks, especially across international or ported numbers.
- iPhone transfer issues: Users migrating to a new iPhone might inadvertently carry over conflicting SIM/eSIM settings.
- Edge-case hardware or software conflicts: Unique setups (dual SIM, multiple profiles, old backup remnants) might confuse the activation logic.
If the recommended fix fails:
- Reboot your iPhone, then retry activation
- Reset network settings (this removes saved Wi-Fi and VPN setups)
- Sign out and back into your Apple ID
- Contact Apple Support with diagnostics, error codes, or activation logs
In some community threads, users have said they had to persistently reach out to support over days to receive a tailored resolution.
What Apple Can Learn & Next Steps
This iMessage bug shines a light on how legacy features like dual SIM support and eSIM coexistence can introduce complexity. As Apple pivots more toward eSIM and digital-first connectivity, allowances for “inactive” traces must be better managed in firmware logic.
A few lessons Apple might take:
- Better pre-update validation: Before deploying iOS updates, simulate scenarios with multiple SIM/eSIM states.
- Fallback resilience: If iMessage activation logic detects a conflict, offer a guided override or explicit warning to users.
- Proactive communication: Roll out updates earlier in public forums or support pages to preempt confusion and a flood of complaints.
For affected users, patience may be necessary, especially when interacting with support. But for the broader iOS community, this incident underscores the importance of robust QA around features that seem seamless until misconfiguration strikes.