SIM Card Not Detected or No Service? How to Fix It

By Ammar Aslam · Updated September 29, 2026 · 3 min read

Seeing "No SIM card" or "Emergency calls only" means you can't call, text or use mobile data. The problem might be the SIM card, the phone, or the network. These steps help find which.

1. Toggle Airplane mode

Turn Airplane mode on for 10 seconds, then off. This reconnects the phone to the network.

2. Restart the phone

A restart fixes most temporary SIM detection issues.

3. Remove and reinsert the SIM

Turn off the phone.
Use the SIM ejector tool to open the tray.
Check the SIM for scratches or dirt; wipe the gold contacts gently with a dry, soft cloth.
Reinsert it correctly in the tray and turn the phone on.

4. Test the SIM in another phone

Works in the other phone: your phone may have a setting or hardware issue.
Doesn't work anywhere: the SIM is damaged or blocked. Visit your network's service centre for a replacement with the same number (bring your ID).

5. Check SIM settings

In Settings → SIM cards (or Network & internet → SIMs), make sure the SIM is enabled.
For dual-SIM phones, check which SIM is set for calls and data.
Set Preferred network type to automatic (5G/4G/3G/2G).
Try selecting your network manually under Network operators.

6. Reset network settings

Android: Settings → System → Reset options → Reset Wi-Fi, mobile & Bluetooth. iPhone: Settings → General → Transfer or Reset iPhone → Reset → Reset Network Settings.

7. Check SIM registration and blocking

In many countries, SIMs must be registered with your ID, and unregistered or unverified SIMs can be blocked. If you recently bought the phone from abroad, it may also need to be registered with the local telecom authority to work on local networks. Contact your network if in doubt.

8. eSIM issues

For eSIMs, check the eSIM is turned on. If you reset your phone or deleted the eSIM, contact your network to issue a new eSIM QR code.

9. Hardware problems

If no SIM works in your phone, the SIM reader may be damaged, often after a drop or water exposure. Visit an authorised service centre.

Lost signal suddenly? Check if your network has an outage in your area before trying fixes.

Dual SIM tips

Many phones hold two SIMs, or a physical SIM plus an eSIM. Dual SIM causes some confusing issues:

Data on the wrong SIM: choose your preferred data SIM in SIM settings. Turn off automatic data switching if it keeps changing.
One SIM loses 4G/5G: on some phones, only one SIM at a time can use the fastest network. Put your main SIM in the primary slot or set it as the data SIM.
Calls not reaching the second SIM: during a call on one SIM, the other may be unreachable. Some phones support "dual SIM always on" call forwarding.
Memory card and SIM share a slot: on hybrid trays, you can use either a second SIM or a memory card, not both.

Moving your SIM to a new phone

Turn off both phones before moving the SIM.
Check the new phone's SIM size (most use Nano SIM). Networks can replace old larger SIMs.
For eSIMs, use the phone's eSIM transfer feature or ask your network for a new eSIM QR code.
Re-register banking and wallet apps, which are often tied to your SIM and device.

Protect your SIM

Set a SIM PIN in security settings so a stolen SIM can't be used in another phone, and learn the warning signs of SIM swap scams. Keep a note of your PUK code (from the SIM card holder or your network) in case you enter the PIN wrong too many times.

Frequently asked questions

Why does my phone say "Emergency calls only"?

The phone can reach a network but not register on yours, often due to poor signal, a blocked SIM or network issues.

Will a new SIM keep my number and contacts?

A replacement SIM keeps your number. Contacts saved on your Google account aren't affected. See backing up contacts.

Ammar Aslam
Ammar writes clear, practical tech guides that help everyday users fix problems, stay safe online and get more from their devices.