[samfromnz]

My iPhone has so little free space (thanks to the ever increasing “system data”) that it can’t update to iOS 26. Point updates for iOS 18 are usually much smaller and can still be installed.

I can’t believe I’m suggesting this, but… you could install a bunch of apps to get your phone storage to <10GB free, which should block it being able to update to iOS 26.

[deltoidmaximus]

This was a trick to block Windows updates at one point, but then they started force reserving 7GB or something with a later update. It meant that some devices with small disks that supported Windows 10 no longer met the system requirements.