Symptoms
- Error explicitly says 'SIM failure' or 'invalid SIM'
- Error appears right after inserting a SIM
- SIM was working and then this error appeared suddenly
- Error persists across restarts
Likely causes
- CommonSIM not seated correctly in the trayAn improperly inserted SIM breaks the electrical contact needed for detection.
- CommonDamaged or worn SIM cardPhysical wear or a manufacturing defect can trigger this specific error.
- PossibleDirty contacts on the SIM or the phone's SIM readerBuildup can interfere with a proper connection.
- Less commonPhone's SIM tray or reader hardware faultAfter a drop or liquid exposure, the reader itself can fail.
What to do
- Power off the phone, remove the SIM tray, and inspect the SIM for visible damage or dirt.
- Clean the SIM's gold contacts gently with a dry cloth and reseat it firmly in the tray.
- Try the SIM in a different phone to see if the error follows the SIM.
- Try a different known-working SIM in your phone to see if the error follows the phone instead.
- Restart the phone after reseating the SIM.
- Request a replacement SIM from your carrier if the SIM itself appears to be the issue.
Tools and parts
- SIM ejector tool
- Soft dry cloth
Replacement SIM cardSearch: “replacement SIM card [your carrier name]”
When to call a pro
If a known-good SIM still triggers 'SIM failure' in your phone, the SIM tray or reader hardware likely needs professional repair.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.