Why Does My Phone Say No Service? iPhone and Android Fixes

No Service means your phone is not connected to its cellular carrier, so calls, texts, and mobile data may fail even though Wi-Fi still works. Common causes include weak coverage, an outage, a temporary software glitch, an inactive SIM or eSIM, an account issue, or device damage. If signal bars and calls work but apps cannot connect, troubleshoot mobile data instead.

On iPhone, SOS or SOS Only means your usual carrier is unavailable; emergency calls may work through another network in some regions.

Try these checks first on any phone

1. Refresh the cellular connection

Open Settings and turn on Airplane Mode. Leave it on for at least 15 seconds, then turn it off. This makes the phone search for a cellular network again. On Android, you can use the Quick Settings panel or the Airplane Mode setting. Confirm that the mode is off afterward.

2. Test in a different location

Move outdoors or near an exterior window, away from basements, elevators, and thick concrete walls. Buildings and other obstructions can weaken reception. If service returns elsewhere, check your carrier’s coverage and outage information; repeated dead zones may be a network limitation rather than a phone fault. To check cellular reception itself, temporarily turn Wi-Fi off and look for a signal indicator.

3. Restart the phone

Restart normally using the power controls, then wait for the carrier name or signal indicator to return. A restart is a low-risk way to clear a temporary software or radio state. Install a pending operating-system update when you have a stable Wi-Fi connection, especially if the issue began after a software change.

Check your SIM or eSIM

If the phone says No SIM or “Emergency calls only,” check whether the SIM or eSIM line is present, enabled, and activated by your carrier.

• Physical SIM: Follow your phone maker’s removal instructions, then check that the card is seated flat and undamaged. Wipe dust with a soft, dry cloth; do not use liquid or force the tray. Ask the carrier for a replacement if the card is bent or not detected.
• iPhone: Open Settings > Cellular, select the line, and turn it on if needed. If the line is missing after a SIM or eSIM change, ask your carrier to activate it. Follow Apple’s SIM and eSIM guidance.
• Android: On Pixel, open Settings > Network & internet > SIMs, select the carrier, and check that Use SIM is on. Menus vary by brand; look under SIMs, Connections, or Mobile network. Don’t delete an eSIM profile unless your carrier tells you to. See Google’s Pixel connectivity guide or Samsung’s SIM troubleshooting steps.

Update carrier settings, then consider a network reset

On iPhone, connect to Wi-Fi and open Settings > General > About. Install a carrier settings update if prompted, and check for an iOS update. A new SIM or eSIM may need updated carrier settings; see Apple’s instructions. On Android, check for a system update in Settings; the route varies by manufacturer.

If the simpler steps fail, reset network settings—not the whole phone. On iPhone, go to Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings. This clears saved Wi-Fi networks and passwords, VPN, and APN settings. Android reset options vary; read the notice because some phones also reset Wi-Fi or Bluetooth settings.

A network reset cannot activate a line or repair hardware. Avoid a factory reset unless support recommends it and your data is backed up.

When to contact your carrier or phone maker

Contact your carrier if service stays down in several locations, the line is missing, or the problem began after a plan change, number transfer, SIM swap, or trip. Ask it to verify account status, SIM/eSIM activation, local outages or blocks, and device compatibility. Only the carrier can check line provisioning and account restrictions. Travelers should confirm roaming support and charges before enabling it.

If the carrier confirms the line and local network are working but the phone still cannot connect, use the manufacturer’s support or diagnostics. Apple says iPhones running iOS 18 or later can use the Apple Support app for additional diagnostics. A damaged phone, liquid exposure, or a problem that persists with a known-working SIM may need professional service.

If this happens often in one area

Ask your carrier whether Wi-Fi Calling is available for your device, line, and country. When supported and enabled, it can route calls over Wi-Fi where cellular reception is poor; it does not restore cellular service itself. If the failure follows the phone from place to place, focus on the SIM/eSIM, account provisioning, updates, or device support instead of repeatedly toggling settings.