AT&T Warns iPhone 18 Pro Max Users Some Phones Can't Call 911, Urges Immediate Update as Problems Persist

DALLAS — AT&T is urging customers with Apple's new iPhone 18 Pro Max to update their software immediately. The carrier acknowledged that some of the devices on its network cannot reliably make calls, send texts or use data, including calls to 911.

In a text message sent to customers Thursday, AT&T said an important Apple software update was available for the phone and advised users to install iOS 27.0.1 right away. Many affected users, however, say the update has not fixed the problem.

The warning is the first public acknowledgment from the carrier of a problem that has frustrated thousands of iPhone 18 Pro Max owners since the phone's launch last month.

AT&T's message to customers

The text message, as reported by MacRumors, reads:

"Hi, it's AT&T. Action needed: An important Apple software update for your iPhone 18 Pro Max is available. Some phones may be unable to complete calls/text/data, including to 911. Update to iOS 27.0.1 immediately — Settings > General > Software Update. Please contact AT&T or Apple if you have questions."

The mention of 911 adds urgency to the problem. A phone that cannot reach emergency services could put users at risk in a crisis.

MacRumors noted the irony of AT&T using a text message to warn users that they may be unable to send or receive text messages.

Update may not fix the problem

Apple's release notes for iOS 27.0.1 do not mention a fix for cellular connectivity on AT&T. Instead, the update addressed a Face ID issue on the iPhone 18 Pro models.

Users across Apple's Support Community, Reddit and the MacRumors forums have reported that the update did not solve their connection problems. At least thousands of users appear to have been affected, based on discussions across those platforms.

Some industry observers noted that iOS updates are also used to deliver carrier settings and modem firmware, which could explain why AT&T is directing customers to update even though Apple's notes do not mention the issue.

What users are experiencing

Affected iPhone 18 Pro Max owners say they are unable to connect to AT&T's network for calls, texts or data, either persistently or intermittently. Their phones typically switch to SOS mode, which allows only emergency calls through other carriers' networks when available.

The problem appears to be limited to AT&T customers. Users on other carriers have not widely reported similar issues.

The underlying cause has not been confirmed, and Apple has not publicly commented on the matter.

A possible modem link

One detail drawing attention is the phone's cellular modem. The U.S. version of the iPhone 18 Pro Max is the only new iPhone introduced last month that uses a Qualcomm modem, according to MacRumors.

The smaller iPhone 18 Pro and the foldable iPhone Duo use Apple's in-house C2 modem worldwide, as does the iPhone 18 Pro Max sold outside the United States.

It is unclear whether the Qualcomm modem is a factor in the problems. Some users noted that Qualcomm modems have been used in previous iPhone models without similar widespread problems on AT&T.

Apple has been moving away from Qualcomm modems as it develops its own chips, a multiyear effort aimed at reducing reliance on outside suppliers.

Software or hardware?

If the problem is caused by software, Apple could release another update, such as iOS 27.0.2, to address it. A hardware problem would be far more serious and could require repairs or replacements.

Some users and analysts have said a hardware flaw appears unlikely because the problem seems specific to one carrier. Still, without a confirmed cause, affected customers are left waiting for a fix.

Other launch issues

The connectivity problems add to a list of early complaints about Apple's new lineup. Some iPhone 18 Pro users have reported Face ID trouble, particularly in low light. Apple's iOS 27.0.1 update targeted a Face ID issue, though some users say they continue to experience slower or less responsive recognition.

The iPhone 18 Pro and Pro Max were unveiled at Apple's "Surprise and Shine" event on Sept. 9, alongside the foldable iPhone Duo, new Apple Watch models and AirPods 5.

What affected users can do

AT&T customers who are experiencing problems are advised to:

• Install iOS 27.0.1 through Settings, then General, then Software Update.
• Restart the phone after updating.
• Check for carrier settings updates, which may appear as a prompt.
• Contact AT&T or Apple support if the problem continues.

Users who rely on their phones for emergencies should be aware that their devices may not be able to place 911 calls through AT&T's network until the issue is resolved. Keeping a backup phone or alternative means of contacting emergency services may be advisable for those affected.

Apple and AT&T have not said when a full fix will be available. Customers will be watching for another iOS update or official guidance from either company that explains the cause and confirms a solution.

The problem is an early test for Apple's newest flagship phone, which is among the company's most expensive models, at a time when it is also launching its first foldable iPhone.