Quick answer
If your phone doesn't detect the SIM card, first check that it's inserted correctly and the contacts are clean. Then restart the phone, test the card in another device, and reset network settings. If the problem persists, contact service or your carrier.
How to recognize the problem
- Message "No SIM card" or "SIM card not detected"
- Signal icon is off or shows an X
- Cannot make calls or send SMS
- Mobile data not working even though data is enabled
- Phone intermittently loses network
Most common causes
Loose SIM card
The card may not be seated properly in the slot or the slot may be damaged.
Dirty or damaged contacts
Dust, grease, or scratches on the gold contacts can break the connection.
Faulty SIM card
The card is old, physically damaged, or there's an error with the carrier.
Software issue
Network settings or a software glitch can prevent the card from being recognized.
Faulty SIM card reader
A fault in the slot or motherboard requires service.
Step-by-step fix
- 1
Check that the SIM card is inserted correctly
Turn off the phone, remove the SIM card tray, and check that the card is oriented correctly. Make sure it sits flush with the tray and doesn't protrude. Carefully reinsert the tray until it clicks.
- 2
Clean the SIM card contacts
Remove the card and wipe the gold contacts with a soft, dry cloth. Do not use water, alcohol, or abrasive cleaners. If there is visible dirt on the contacts, gently remove it with a dry brush.
- 3
Restart the phone
Sometimes a simple restart is enough. Hold the power button and select
Restart. Wait for the phone to boot up again and check if the network is available. - 4
Test the SIM card in another phone
If you have another phone, insert the card into it. If there's no network there either, the card is likely faulty or there's an issue with the carrier. If it works in the other phone, the problem is with your device.
- 5
Check network settings
Go to
Settings>Network & internet>Mobile networkand make sureMobile datais turned on. Also check in theCarrierssection that the correct carrier is selected. If needed, enable automatic network selection. - 6
Reset network settings
In
Settings>System>Reset options>Reset Wi-Fi, mobile & Bluetooth, confirm the reset. This will erase saved Wi-Fi networks, Bluetooth pairings, and access point (APN) settings, but not personal data. If mobile data doesn't work after the reset, APN settings usually restore automatically or you can request them from your carrier. - 7
Update software
Check if a system update is available:
Settings>System>System update>Check for updates. Install available updates and restart the phone. - 8
Replace the SIM card
If none of the above helps, contact your carrier to replace the SIM card. A new card will likely solve the problem if the old one is damaged.
If nothing helps
If you've tried all the steps and the phone still doesn't detect the SIM card, the card reader may be faulty. In that case, contact an authorized service center. Before going to service, back up your data. Also, check if the phone is carrier-locked (SIM lock), which you can verify with your carrier. If the phone is under warranty, do not attempt to open it yourself.
How to prevent it
- Handle the SIM card carefully when removing and inserting it, and do not use cut cards or improvised adapters.
- Regularly update your phone's software.
- Use a protective case that does not block the SIM card slot.
- Avoid exposing the phone to moisture and dust.
When to call a professional
If you suspect a hardware fault in the SIM card reader or the phone doesn't respond to any software step, contact IT support or an authorized service center.
IT infrastructure maintenance · Servers, networks, backup, security and helpdeskFAQ
Why doesn't the phone detect the SIM card after a system update?
An update can sometimes disrupt network settings. Reset network settings or restart the phone. If the problem persists, check if the card works in another device.
Is it safe to remove the SIM card while the phone is on?
Most modern phones support hot-swap, but it's recommended to turn off the phone before removing the card to avoid damage or data loss.
How do I know if the problem is with the carrier?
If the card doesn't work in another phone either, the problem is likely with the carrier or the card itself. Call your carrier's customer service to check the card's status.