Toggle Airplane Mode, restart, check for a carrier settings update in Settings → General → About, make sure your SIM or eSIM line is turned on, and check for an outage. Try another SIM or a different location. If it shows No Service everywhere, or Modem Firmware is blank in Settings → General → About, it's likely a hardware fault on the logic board.
Quick fixes
- Turn Airplane Mode on, wait 15 seconds, and turn it off.
- Restart the iPhone.
- Open Settings → Cellular and make sure your line is turned on.
- Go to Settings → General → About. If a carrier settings update is available, you'll be prompted to install it.
- Update iOS in Settings → General → Software Update.
- If you use a physical SIM, take it out and put it back. iPhone 14 and later models sold in the US use eSIM only.
Reset network settings
Open Settings → General → Transfer or Reset iPhone → Reset → Reset Network Settings. This clears saved Wi-Fi passwords, VPN and cellular settings, but it doesn't erase your data. It fixes a surprising number of signal problems.
If you just switched phones or carriers
No Service right after an upgrade or a carrier switch is usually an activation issue, not a broken phone. If you moved to a new iPhone, check that your eSIM finished transferring in Settings → Cellular. If you switched carriers, make sure the old line was released and the phone is unlocked. A carrier-locked iPhone won't connect with another carrier's SIM.
Your carrier can check the line's status, re-send an eSIM, or confirm that the phone's IMEI is active on your account. Have the IMEI ready from Settings → General → About.
Stay reachable while you sort it out
If you have Wi-Fi, turn on Wi-Fi Calling in Settings → Cellular → Wi-Fi Calling (if your carrier supports it). You can make and receive calls and texts over Wi-Fi while you work out whether it's the network or the phone.
Is it your carrier?
- Check your carrier's outage page or social accounts.
- Make sure your account is active and paid.
- Try your SIM in another phone, or another SIM in your iPhone.
- Test in a different spot. Basements, rural roads and some buildings have weak coverage.
If you see SOS or SOS only, your iPhone can't reach your carrier, but emergency calls may still go through another network.
Signs of a hardware fault
- No Service everywhere, even with a SIM that works in another phone.
- It's always Searching.
- The Modem Firmware field in Settings → General → About is blank.
- It started after a drop or liquid exposure.
- The top of the phone gets warm while it's searching.
The part that talks to the cell network, the baseband, lives on the logic board. Some older models have known faults here. Apple once ran a repair program for certain iPhone 7 units with exactly this symptom.
How it's fixed
Baseband faults need a board-level repair, which is done under the microscope and usually keeps your data. Sometimes the fault is simpler, like a damaged antenna cable or a loose connection after a drop, and those are quicker fixes. If the phone got wet, a water damage repair comes first. The diagnosis is free, so you'll know whether it's the phone or the network before you pay anything.
Frequently asked questions
Why does my iPhone say SOS?
Your iPhone can't connect to your carrier, but it can still place emergency calls through other networks where that's supported.
Will resetting network settings delete my data?
No. It only resets Wi-Fi, cellular, VPN and Bluetooth settings. Your photos, messages and apps stay.
Can an iPhone with No Service be fixed?
Usually. If it's a setting or carrier issue it's free to fix. If it's a baseband fault on the board, it needs a board-level repair.
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