Apple confirmed today that a “small number” of iPhone 18 Pro Max users on the AT&T network were experiencing an issue that caused the device to lose cellular service, preventing phone calls, text messages, and data from working. Thousands of users have complained about the issue in 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 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 immediately. To install the update, open the Settings app on your iPhone and tap General → Software Update.
According to Apple, the carrier settings update for the iPhone 18 Pro Max will be automatically downloaded for AT&T users in the next 14 days. To manually trigger the update, users can open the Settings app and tap General → About.
Apple’s full statement:
We have identified an issue affecting a small number of iPhone 18 Pro Max users on the AT&T network that may cause a device to lose service and be unable to make calls. We released iOS 27.0.1 earlier this week and strongly encourage all iPhone 18 Pro Max users to update it now, and we’re also releasing a carrier settings update today. These updates together are intended to help prevent this issue from occurring.
Specifically, Apple said that iPhone 18 Pro Max devices that were affected by this cellular issue on the AT&T network cannot have service reactivated with a software update. Instead, Apple said the device needs to be completely replaced and advises affected customers to contact Apple or AT&T support or visit an Apple Store or AT&T location.
Apple said it has only observed this issue with iPhone 18 Pro Max users on the AT&T network. No other iPhone models or carriers appear to be affected.
Apple has not disclosed 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 whether this modem difference is a factor in this AT&T problem.
It’s also unclear whether an Apple support program dedicated to this issue will eventually be created. In the meantime, it looks like Apple Stores will replace affected iPhone 18 Pro Max devices for free, so book an appointment at the Genius Bar if needed.
