Apple says iPhone 18 Pro Max users suffering from AT&T cellular issue should get device replaced

Apple confirmed today that a “small number” of iPhone 18 Pro Max users on the AT&T network have experienced an issue that causes the device to lose cellular service, preventing phone calls, text messages, and data from working. Thousands of users have complained about the issue within the Apple Support Community and on other platforms.

Apple said it released iOS 27.0.1 earlier this week and an AT&T carrier settings update earlier today to prevent more iPhone 18 Pro Max users from being affected by this issue in the future. In a statement shared with MacRumorsApple has strongly encouraged all iPhone 18 Pro Max users to update to iOS 27.0.1 now. To install the update, open the Settings app on your iPhone and tap General → Software Update.

The carrier settings update for the iPhone 18 Pro Max will automatically download for AT&T users over the next 14 days, according to Apple. To manually trigger the update, users can open the Settings app and tap General → About.

Full statement from Apple:

We have identified an issue affecting a small number of iPhone 18 Pro Max users on the AT&T network that may result in a device losing service and being unable to make calls. We released iOS 27.0.1 earlier this week and strongly encourage all iPhone 18 Pro Max users to update now, and are also releasing a carrier settings update today. Together, these updates aim to prevent this issue from occurring.

Notably, Apple said that iPhone 18 Pro Max devices that were affected by this cellular issue on the AT&T network may not have the service re-enabled with a software update. Instead, Apple said the device needs to be replaced entirely and is advising affected customers to contact Apple or AT&T support, or visit an Apple or AT&T Store.

Apple said it only observed this issue with iPhone 18 Pro Max users on the AT&T network. No other iPhone models or carriers are known to be affected.

Apple has not revealed the underlying cause of the problem. US models of the iPhone 18 Pro Max rely on Qualcomm’s Snapdragon X80 modem for cellular connectivity, while variants of the device sold in all other countries feature Apple’s custom C2 modem. It’s unclear if this modem difference is a factor in this AT&T issue.

It’s also unclear if there will eventually be an Apple service program dedicated to this issue. In the meantime, it looks like Apple Stores will replace affected iPhone 18 Pro Max devices for free, so make an appointment with the Genius Bar if necessary.