Apple has updated its iMessage troubleshooting support document to address a new issue affecting iPhone users running iOS 26. The company confirms that if you skip activating iMessage or an eSIM during the initial setup of a new iPhone, the service may not function correctly afterward.
Following the release of iOS 26, several users began reporting issues such as messages showing a “Not Delivered” alert, being sent as SMS or RCS in green bubbles, or being delivered from an email address instead of a phone number. These problems typically appear when an iMessage account isn’t automatically linked to an eSIM added later through the Settings app.
According to Apple, this behavior is not a system error but a result of how iOS 26 manages activation flows. When a user sets up an eSIM after the initial configuration, iMessage does not automatically activate. Instead, it requires manual reactivation. This affects both new iPhone owners who delayed eSIM setup and existing users who switch
To fix the issue, Apple recommends a simple process:
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Make sure your eSIM is activated in the Settings app.
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Open the Settings app again.
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Tap on Apps.
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Select Messages.
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Turn iMessage off.
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Wait a few seconds, then turn iMessage back on.
This quick sequence manually reestablishes the link between your phone number and iMessage, restoring the usual blue bubble experience.
The clarification from Apple provides reassurance to users encountering iMessage issues after updating to iOS 26 or migrating to a new device. By following these steps, messages that previously failed to send or appeared as SMS/RCS should once again deliver correctly through iMessage.
The update also highlights how Apple continues to refine its activation procedures with each major iOS release. While iOS 26 introduces numerous improvements across system performance and connectivity, the new activation logic for eSIMs appears to have created an unexpected learning curve. Apple’s prompt documentation update ensures that users can quickly diagnose and resolve these connectivity hiccups without needing further assistance.
