- Restart your device
This will help reset the phone back to its factory settings, refreshing the memory and helping it recognize the SIM. - Check and clean the SIM tray
Confirm that the SIM card is inserted properly and the tray is free of dust and debris. - Ensure that the SIM is activated
Contact your phone service provider to ensure that the SIM card is active. If the SIM is active, but the phone does not recognize it after being restarted, you may need to manually configure the phone's network settings. - Update network settings
If your phone provider was unable to activate the SIM card, take it to a phone store for proper configuration. - Confirm that the current device or SIM is compatible with the network
If the phone is coming from a different country than your provider, the device may not be able to access the network.
