iPhone users on iOS 27 can no longer downgrade to iOS 26

If you updated to iOS 27 and were hoping to go back, that window has just closed.

Apple stopped signing iOS 26.6.2 on September 21, which means iPhones running iOS 27 can no longer be downgraded to iOS 26 through official means. The change was spotted by Aaron Perris on X.

What no longer signing means

Every time you install iOS, even via Finder or IPSW, your iPhone checks with Apple to confirm that version is still authorized. Apple calls this signing.

Apple keeps that list short on purpose. Older releases often contain security flaws that newer updates have patched, so blocking downgrades keeps more devices on protected builds. Once a version is unsigned, you can’t install it anymore, even if you have the file saved.

With iOS 26.6.2 now unsigned, iOS 27 is the only iPhone restore path Apple allows.

What about iOS 26.7?

Apple released iOS 26.7 last week, and that might sound like an alternative way back. It’s not, at least not for iPhones on iOS 27.

Apple hasn’t published an official iPhone restore image for iOS 26.7, unlike iPadOS 26.7. If you’re still on iOS 26, you can get 26.7 as an over-the-air update. If you’re already on iOS 27, there’s no IPSW to restore with, so you can’t use 26.7 to downgrade either.

In practice, iPhone users on iOS 27 are now forward-only until the next iOS 27 update.

Should you worry?

This is Apple’s normal pattern. The company typically stops signing the previous release a week or two after a major version lands. iOS 27 started rolling out widely in mid-September, so the timing tracks.

If you’re on iOS 27 and running into bugs, the better path is to wait for the next patch or report issues and try the usual fixes for iOS 27 rather than counting on a downgrade. And if you’re still on iOS 26 and on the fence, know that updating to iOS 27 locks you in once this signing window closes.

If you need the old method for reference, our guide on how to downgrade iOS on iPhone explains how signing and restores worked when a downgrade was still possible.