When you attempt to call using a SIM card that is not registered to its designated carrier service provider, you will get the error message “Not registered on network.” This blocks you from making any calls since the service provider cannot recognize the SIM.
Usually, the service provider disables a SIM card when it is reported stolen or is not in use for a long time. But issues like a missing IMEI number and incorrect network type selection could also cause the error.
Dust and debris stuck in the area where the SIM comes in contact with the phone could restrict communication between the two components. To ensure that it is not the case, try cleaning the SIM and the SIM card slot.
Check if Your Device Shows IMEI Number
The mobile service provider uses your phone’s IMEI (International Mobile Equipment Identity) number to identify your device on the network and cannot make a call without it.
The IMEI number is stored in the phone’s EFS (Encrypting File System) partition. And if this partition is corrupted, the phone might not have an IMEI number. Complications during a jailbreak, root, or when installing a custom OS could cause problems with the EFS partition. Another reason the IMEI number is missing could be due to the phone’s firmware corruption.
To check your device’s IMEI number, press*#06#on the call dialer. If it shows Null or Invalid, it means your device cannot access the IMEI number saved in the phone’s ROM.
If you have not performed any jailbreak/root on your phone, we recommend that you check the phone’s warranty. If the warranty is not void, the manufacturing company might be able to install new firmware on your phone for free.
You cannot claim a warranty if you have performed a jailbreak or rooted your device. In such a case, you need to visit a local repair shop.
Change Preferred Network Type
The SIM may run into issues even when it has good connectivity in a selected Network type. The phone automatically selects between 2G, 3G, 4G, and5G networksdepending on connectivity.
If the selected network does not work, you need to change Preferred Network Type.
Disable Automatic Network Selection
By default, your phone will automatically select its designated network. If it fails to do this, it cannot register your call to carrier service, and you will get an error message. To fix this, you need to select the network manually.
Check for System Update
