Last updated: October 4, 2026
The quick answer
Apple has confirmed that a small number of iPhone 18 Pro Max phones on AT&T can suddenly lose cellular service and show SOS instead of signal bars. If your phone still works, install iOS 27.0.1 and the latest carrier settings right away to prevent the problem; if it has already lost service, software will not bring it back and Apple says the phone needs a hardware replacement.
What happened
Within the first two weeks of the iPhone 18 Pro Max going on sale, owners on AT&T began reporting that their phones had dropped off the network. Instead of signal bars, the status bar showed SOS, and the phones could no longer place normal calls, send texts or use 4G or 5G data. Complaints piled up in Apple’s support forums and on social media.
On October 2, Apple publicly acknowledged the issue. In a statement shared with several outlets, the company said it had identified a problem affecting “a small number of iPhone 18 Pro Max users on the AT&T network” that can cause the device to lose service. Apple released iOS 27.0.1 earlier in the week, and AT&T pushed a carrier settings update, both designed to stop the failure from happening.
The important catch: those updates are preventive. Apple says phones that have already experienced the failure need to be replaced, because the fix cannot restore service once the problem has occurred.
Reports note that in the US, the iPhone 18 Pro Max is the only model in the new lineup that uses a Qualcomm cellular modem rather than Apple’s own modem. Apple has not said the modem is the cause, so treat that as context rather than an explanation.
What changes for you
| Your situation | What to do |
|---|---|
| iPhone 18 Pro Max on AT&T, service still working | Install iOS 27.0.1 and the carrier settings update now to prevent the failure |
| iPhone 18 Pro Max on AT&T, stuck on SOS | Updates will not fix it; contact Apple or AT&T for a hardware replacement |
| iPhone 18 Pro Max on another carrier | Apple has only confirmed the issue on AT&T, but installing iOS 27.0.1 is still sensible |
| Other iPhone 18 models | Not part of this confirmed issue |
How to protect a working iPhone 18 Pro Max
- Back up first: make sure an iCloud or computer backup is current, which also makes a possible replacement much easier.
- Install iOS 27.0.1: go to Settings > General > Software Update and install it while you are on Wi-Fi with enough battery.
- Get the carrier settings update: open Settings > General > About and wait a few seconds. If an update is available, a prompt appears; tap Update. Reports say the update is also being delivered automatically over about two weeks, but there is no reason to wait.
- Check that both are in place: Settings > General > About shows your iOS version and, under your carrier entry, the carrier settings version.
If your phone is already stuck on SOS
- Confirm the symptom: SOS in the status bar with no normal calls, texts or cellular data, even in places where AT&T coverage is usually good.
- Back up over Wi-Fi: the phone still works on Wi-Fi, so run an iCloud backup before you hand it over.
- Request a replacement: contact Apple Support, book a visit to an Apple Store, or go to an AT&T store. Mention that Apple has acknowledged the AT&T service-loss issue on the iPhone 18 Pro Max.
- Plan for the gap: until the replacement arrives, Wi-Fi Calling (Settings > Cellular > Wi-Fi Calling) may help at home, and it is wise to keep another way to reach people in an emergency.
- Check your eSIM afterwards: on the new phone, make sure your AT&T line transfers correctly before you leave the store or finish setup.
Who it affects and who it doesn’t
- Affects: a limited number of iPhone 18 Pro Max owners using AT&T in the US.
- Should still update: every iPhone 18 Pro Max owner on AT&T, even if nothing has gone wrong yet, because the updates are what prevent the failure.
- Not affected, according to Apple’s statement and reporting: customers on other carriers and owners of other iPhone 18 models.
Shopping for a phone instead? Prices are moving this month; see our guide to the Pixel 10a and Galaxy A-series price increases. Mac owners may also want to read about Apple tightening Full Disk Access because of AI agents.
FAQ
Will iOS 27.0.1 fix a phone that already shows SOS?
No. Apple says the update and the carrier settings are meant to stop the problem from happening. A phone that has already lost service needs a hardware replacement.
Is my phone safe after updating?
According to Apple’s explanation as reported by several outlets, a phone that has not failed should be protected once iOS 27.0.1 and the new carrier settings are installed. If you see SOS afterwards, contact Apple or AT&T.
Should I switch carriers or return the phone?
There is no need for drastic moves if your phone works: update it and keep using it. If it has already failed, the replacement route Apple describes is the direct fix. Return windows depend on where you bought the phone, so check the seller’s policy if you are weighing a refund.
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