How to Update an iPhone to iOS 27

Apple releases iOS 27 on Monday, September 14, 2026. Until it appears on your phone, Software Update shows iOS 26.6.x and nothing else, which is normal rather than a fault. Most failed updates come down to three things: a phone that is almost full, a cellular connection, and an old version of iOS 26 that could not download updates at all.

Check that the phone can run iOS 27

Open Settings, General, About and read the Model Name. iOS 27 runs on iPhone 11 and later, and on iPhone SE (2nd generation or later). An iPhone XS, XS Max, or XR stops at iOS 26. If your phone is not on the list, no setting or app changes that.

Install iOS 26.6.2 first if it is offered

Open Settings, General, Software Update. If it offers iOS 26.6.2, install that now. It fixes a bug in the 26.6 releases that blocked downloading any update over a cellular connection, and it takes a few minutes.

Free up space and get on Wi-Fi and power

Open Settings, General, iPhone Storage and delete enough that several gigabytes are free. Offload an app or two if the number will not move. Then join Wi-Fi, plug the phone in, and turn off Low Data Mode under Settings, Cellular if you use it.

Back up before you start

Open Settings, tap your name, then iCloud, iCloud Backup, Back Up Now. Wait for it to finish. A major update rarely loses data, but a restore is the only way back if something goes wrong.

Install iOS 27

Return to Settings, General, Software Update, tap Download and Install next to iOS 27, and enter your passcode. Leave the phone alone while it downloads and restarts. When it comes back, Settings, General, About should say 27.

Fix an update that sticks or fails

If it sits on Update Requested, or says Software Update Failed, turn off any VPN, rejoin Wi-Fi, restart the phone, and open Software Update again. If it still will not move, connect the phone to a computer, open Finder (or the Apple Devices app on Windows), select the iPhone, and update from there.

You cannot go back. Once Apple stops signing iOS 26, downgrading is not possible, and no tool changes that.

If iOS 27 is not offered yet. Before September 14 it will not be there at all, and on release day Apple rolls it out in waves, so pull down on the Software Update screen to refresh and check again later. Do not install a beta profile to jump the queue.