Apple opened App Store submissions for iOS 27 and iPadOS 27 on 10 September 2026, four days ahead of the public rollout on 14 September. That’s the normal cadence. What’s less routine is the line further down the developer notes: starting April 2027, every new app and every update submitted to the App Store must be built with the iOS 27 or iPadOS 27 SDK or later. Apps that don’t meet it won’t be accepted — not flagged, not warned, rejected.
macOS 27 carries its own version of the same shift: it drops support for Intel Macs entirely, running on Apple silicon only, which closes out a transition Apple’s been signalling since Rosetta was marked as ending with macOS 26.
Why this isn’t just a developer housekeeping note
SDK deadlines like this have a habit of arriving in commissioning conversations far later than they should. A business that briefs a new app build in early 2027 without checking the SDK requirement can find itself submitting to a platform that no longer accepts it — or discovering mid-project that a third-party library or contractor’s toolchain hasn’t been updated. The gap between “we’re building an app” and “we’re building an app that Apple will actually accept” is exactly the kind of detail that gets missed when software is commissioned casually, and caught immediately when it’s scoped properly.
So what
If you’ve got an iOS app in market that hasn’t been rebuilt against a current SDK in the last year, or you’re about to commission one, April 2027 is now a real date on your roadmap, not a distant platform update. It’s worth checking with whoever maintains your app — internal team or agency — that they’re already building against iOS 27. If you’re planning a new build or a stalled app needs bringing current, our iOS & Android development work starts every project on the current SDK as standard, so deadlines like this one never become a surprise.