Typically, once Apple launches a significant software update, it allows users to revert to the previous version for several weeks. Nevertheless, it appears that the company is strongly encouraging the iOS 26 update, as it is the sole version available on iPhones.
Currently, users with iPhone 11 through iPhone 16 Pro Max cannot revert back to iOS 18.6.2. Thus, if you’re facing issues like bugs or battery drainage with iOS 26, your only alternatives are to install the iOS 26.1 beta 1 – which may bring about new problems – or wait for an upcoming iOS 26.0.1 update.
Apple generally ceases to sign older versions to deter users from reverting to a previous, less secure iOS version. Although Apple isn’t mandating the installation of iOS 26, this adjustment signifies that users who’ve upgraded cannot revert to iOS 18.