Apple has explained why iMessage might not activate on iOS 26 and provided a fix.

iMessages can also be sent using an email address rather than a phone number.

If you have a physical SIM that is not active, remove it from the iPhone. Once the inactive SIM is removed, iMessage can be activated by going to Messages, tapping Send & Receive, and then tapping the phone number shown.

Apple has addressed the most frustrating issues and is offering the above steps if you are having difficulties, which should improve things moving forward. I still support iOS 26 for the time being.

"Iconic Phones" is a beautifully illustrated book that we've spent over a year creating, and it will be released in a couple of months! Revisit some of the most distinctive and unforgettable phones of the past two decades.

"Iconic Phones: Revolution at Your Fingertips" is a coffee table book that every phone enthusiast should own. It tells the stories of more than 20 popular phones, taking you on an unforgettable journey through the technological revolution that has influenced our lives. Sign up now to get a special early discount!