A “No SIM” or “SIM not detected” message means the phone cannot reliably read the physical card. This is different from “No Service”: a readable SIM can still fail to register because of coverage, an account block or a network problem.
Before removing the SIM
- Record the exact message.
- Restart the phone once.
- Install pending software and provider-settings updates.
- Check whether the issue began after impact, liquid exposure, a tray swap or a software update.
Inspect and reseat the card
- Power the phone off if the manufacturer recommends it.
- Use the correct eject tool in the SIM-tray hole, not a nearby microphone opening.
- Check that the card matches the tray size and sits flat.
- Look for cracks, warping, corrosion or badly cut edges.
- Wipe dry dust gently with a clean lint-free cloth; do not use liquid or abrasives.
- Reinsert the original tray without force, then restart.
Test whether the fault follows the card
If privacy and account security allow, try the SIM in another compatible unlocked phone. You can also try a known-working SIM in the affected handset. Interpret the result carefully:
- If the SIM fails in more than one phone, request a replacement from the network.
- If several working SIMs fail in one phone, the tray, reader or modem may need repair.
- If the SIM is detected but shows no service, move to network-registration troubleshooting.
After a phone has been dropped or wet
Do not keep reinserting the card or applying pressure to the tray. Liquid or impact damage can affect the reader even when the SIM appears normal. Power the phone down if it is unsafe to use and seek an authorised inspection.
Dual-SIM and hybrid trays
Confirm that each card occupies the correct position and that a microSD card is not interfering with a hybrid slot. A tray from another phone model may look similar but have different tolerances.
When to contact the network
Ask for a replacement SIM when the card is damaged, no longer recognised by compatible phones, or has been deactivated during a SIM swap. The provider may require identity checks before moving the number.
A real-world check that prevents the common mistake
Prove whether the fault follows the card or the phone without forcing the tray. After a safe inspection, test the SIM in another compatible unlocked phone or test a known-working SIM in the original phone, if both tests are authorised and low risk. Stop immediately if there is water damage, a bent tray or heat.
- Record the exact message before moving the card.
- Keep account details available for a replacement SIM.
- Do not clean contacts with liquid or abrasive material.
Official information checked
Information checked on 25 July 2026. Tray design and safe removal instructions vary by device model.
