Apple today stopped signing iOS 18.2, which means that iPhone users who have upgraded to iOS 18.2.1 can no longer downgrade to iOS 18.2. Apple released iOS 18.2.1 earlier in January. When new versions of iOS are released, Apple typically stops signing the prior version after a week or two. An update that is not signed is not able to be installed on an ‌iPhone‌ because there is a server-side software verification check. By preventing downgrading to older versions of iOS, Apple ensures that users keep their devices up to date with the newest security improvements. Apple's iOS 18.2.1 update included unspecified bug fixes, while the now-unsigned iOS 18.2 update that came out in December added Apple Intelligence features like Image Playground, Siri ChatGPT integration, and Genmoji.