Apple said in a statement on Friday that iPhone 18 Pro Max users who have experienced an issue where AT&T cellular service does not work must have their devices replaced, because the problem apparently cannot be fixed with a software update once it has occurred. Apple and AT&T have not disclosed the underlying cause of the issue.
An AT&T spokesperson directed inquiries to Apple, and Apple has not responded to recent requests for comment. It is possible Apple is still investigating the issue; follow-up questions have been met with radio silence (pun intended).
Apple said iOS 27.0.1 and an AT&T carrier settings update released last week “are meant to help prevent this issue from occurring,” so users who have not experienced the problem should install both updates immediately to avoid potential future impacts.
How iPhone 18 Pro Max users can install the updates
To install iOS 27.0.1, open the Settings app and tap General → Software Update. The carrier settings update for AT&T users will automatically download within the next 14 days; to manually trigger the update, open Settings and tap General → About.
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 are known to be impacted.
U.S. 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 are equipped with Apple’s custom C2 modem. It is unclear if this modem difference is a factor in the AT&T issue, or if the overlap is merely a coincidence.
Apple said a “small number” of iPhone 18 Pro Max users experienced this AT&T issue, which prevents phone calls, text messages, and cellular data from working. Thousands of users have complained about the issue across the Apple Support Community and other platforms.
A request has been made to Qualcomm; any response will be shared if available.
