When you try 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.
Clean the SIM Card
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.
- Power off your cell phone.
- Locate the SIM tray. Look for a small hole on one of the sides of the phone.
- Take a small pin, like a paper clip, and press it into the tiny hole. The SIM tray should pop out.
- Now, gently take the SIM Tray out.
- Clean the gold-colored area on the SIM card using Isopropyl alcohol and a cotton swab.
- Now, try cleaning the SIM tray slot. If you are unsure about cleaning the SIM slot yourself, we recommend going to a cell phone repair center.
- Once the SIM is dry and free from dust, reinsert it back into the SIM tray and insert the SIM tray into your phone.
- Power on your cell phone.
- Try making a call and check if it still gives the error message.
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, and 5G networks depending on connectivity.
If the selected network does not work, you need to change Preferred Network Type.
- Open your phone’s settings.
- Select SIM cards and mobile networks.
- Select the SIM Card. You might have multiple SIM cards listed if your phone supports them.
- Select Preferred Network Type.
- Tap on the network type below the selected one.
- Try calling to see if the error persists. If that does not work, scroll through all network types in the Preferred Network Type list.
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.
- Open Settings and go to SIM cards and mobile networks.
- Select your SIM card.
- Select Mobile networks.
- Disable Automatic Network Selection or enable Manual Network Selection.
- Wait a few moments and select any one network from your carrier service provider.
- Check if you can make a call now.
Check for System Update
Updating your phone to the latest version improves performance, upgrades security, and fixes bugs in the system. If the issue is in the phone’s firmware, updating it should fix the network registration problem.
- Open your phone settings.
- Search for settings like Check for updates. Depending on the phone, these settings will be located in different locations.
- Update your system.
- Check if you can make a call once the update completes.
Contact Service Provider
If none of the solutions work, there is a chance that the problem is with the carrier service provider. There are several reasons a service provider disables a SIM card. They block SIM card that is not in use for a long time, reported stolen, plan is expired or has an outstanding balance.
Either way, you will need to call the service provider’s customer support to unblock your SIM card. In case of a stolen SIM card, only the original owner of the SIM can unblock it.