Apple says the issue may stem from having an inactive SIM with the same number as your active SIM. To fix it, remove the inactive SIM and activate iMessage again.

When enabled, the opt-in Contact Key Verification gives automatic alerts if the iMessage key distribution services return device keys that have not been verified (e.g. if an unrecognized device has ...

At the end of last year, Apple announced iMessage Contact Key Verification, a tool the company said would allow those who face “extraordinary digital threats” to safeguard their conversations from ...

Apple confirms that iMessage may not activate automatically on iPhones running iOS 26 if the eSIM setup is skipped. Here’s ...