How to identify a faulty physical SIM card

  • Updated 

An old, malfunctioning, or damaged physical SIM card can cause unexpected connection issues, rapid battery drain, or performance glitches on your phone. Identifying these symptoms early helps you test your SIM card and verify whether you need a replacement from your network provider.

Signs of a physical SIM card issue

A failing physical SIM card forces your phone to work harder to keep a stable network signal. Look out for these common symptoms:

  • Connectivity issues: Your phone fails to detect the inserted SIM card, displays incorrect APN settings, or cannot connect to WiFi calling and 4G networks supported by your provider.
  • Overheating and rapid battery drain: Your phone feels warm and drains the battery faster because the mobile network modem works harder to maintain a connection.
  • Performance glitches: You experience random restarts or delayed text messages.

How to test your physical SIM card

Follow these chronological steps to verify if your physical SIM card is causing the issue:

  1. Power off your phone and remove the physical SIM card.
  2. Power on your phone and use it without the SIM card inserted.
  3. Check if the overheating, rapid battery drain, or random restarts stop.
  4. Insert a different physical SIM card (newer than two years) into your phone to confirm if your network connection returns.

Testing your old physical SIM card inside a different phone is not a reliable test, as SIM card slot designs vary between phone models.

What to do next

If your testing shows that your original physical SIM card is faulty, contact your mobile network provider to request a replacement SIM card or eSIM.

Still need help?

First try our self-service portal and then reach out to our customer support team. You can also open a support request directly through the My Fairphone app pre-installed on your device.