What problem is affecting some AT&T iPhone 18 Pro Max users?
A small but significant number of iPhone 18 Pro Max devices running on AT&T are experiencing a rare hardware-related issue that completely disables cellular service. If affected, your phone will show ‘SOS’ in the status bar and won’t connect to AT&T's network for calls, texts, or data—in other words, the phone loses all cellular functionality, though Wi-Fi remains usable. This problem currently affects only the iPhone 18 Pro Max model on AT&T. The standard iPhone 18 Pro and other carriers are not impacted.
How can you check if your phone is at risk?
If your iPhone 18 Pro Max has lost cellular service and displays ‘SOS’, you are experiencing this bug and will need a replacement device. For unaffected users, immediate action is important: update your phone to iOS 27.0.1 and ensure you have the latest carrier settings. You can manually prompt the carrier update by navigating to Settings > General > About—if an update is available, you’ll see a prompt. Installing these updates reduces your risk of encountering this issue if you haven’t already been affected.
What should you do if your device is affected?
If your device has lost AT&T service and updating doesn’t help, replacement is the only solution. Contact Apple Support or visit an Apple Store, or reach out to AT&T customer service or in-store staff for assistance. Be sure to back up your iPhone before seeking a replacement to protect your data. Apple is replacing affected phones at no cost due to the hardware nature of the problem.
How does this compare to other carriers and devices?
This bug appears to be exclusive to the iPhone 18 Pro Max on AT&T, with no reports for the iPhone 18 Pro or devices on other networks. If you’re considering switching carriers or devices due to concerns about reliability, it’s worth noting that such large-scale, unfixable hardware issues are uncommon. Always keeping your device up to date with the latest software and carrier settings can help avoid most network-related bugs.
Key takeaways for current and prospective AT&T iPhone users
If you use an iPhone 18 Pro Max on AT&T and have lost cellular service, you’re eligible for a free replacement—don’t delay in contacting support. Unaffected users should immediately update their device OS and carrier settings to prevent the bug. This issue does not affect other iPhone models or users on different carriers, so switching may not be necessary. Staying current with software and carrier updates is your best protection against network disruptions.