Apple iPhones are great smartphones, but there are times when you might face issues. In fact, many iPhone users reported that their iPhone displays “No Sim Card Installed” or “ SIM Not Valid” messages. This means you cannot make or receive calls and enable cellular networks.

There are several reasons for the iPhone No Sim Card error. It could be that your iPhone fails to recognize the Sim Card, or there is a problem with your phone’s software. Whatever the cause and the type of error, we have all the possible fixes for you in the section below.
Method 1: Make sure your Sim Card is Active
Before going any further, you need to ensure that your Sim Card is still active. In fact, the carrier may deactivate your Sim Card if it has been inactive for a few months. To check your iPhone’s Sim Card, go to Settings > Cellular > Cellular Plans. Also, you can contact your carrier and ask for their support.
Method 2: Disable Airplane Mode
If the problem persists, ensure you have disabled Airplane mode on your iPhone. Enabling the Airplane mode will shut down all the wireless networks, including Bluetooth, cellular services, Wi-Fi, and more. Open the Control Center on your iPhone and check if the Airplane mode is now turned on.
Method 3: Remove the Sim Card
The problem may be with the Sim Card itself. In this case, try removing the Sim Card and plugging it back in. Make sure the Sim Card is fully seated and keep your iPhone turned off. Wait for a few seconds and turn your iPhone back on. The No Sim Card Installed error message should disappear, and you should see the carrier name at the top of your device’s screen.
If the problem remains, try removing your Sim Card and check if the Sim slot is dirty. You can use a soft cloth or simply blow into the slot to remove any dirt. Once you are done, insert the Sim card and check if everything works correctly.
Method 4: Restart your iPhone
This is the easiest way to get the cellular network working again on your iPhone. A restart should fix any software-related issues on your device. The steps to restart an iPhone slightly changes depending on which model you now use.
Once your iPhone finishes booting up, check if the problem has been dealt with. If it does not, make sure you read on.
Method 5: Update your iPhone
The No Sim Card issue can be caused by outdated software. In this case, try updating your iPhone to the latest firmware update to see if the problem has been fixed. To update an iPhone, Go to Settings > General > Software Update > Update.
You can turn on Automatic Updates, so your iPhone automatically performs an update if one is available.
Method 6: Reset Network Settings
Since this is a cellular network issue, resetting your network settings might help fix this. You will not lose any data. Instead, your current saved networks, Bluetooth devices, and Wi-Fi passwords will be lost. To do it, go to Settings > General > Transfer Or Reset iPhone > Reset Network Settings > Tap Reset Network Settings.
Method 7: Factory Reset
If none of the above solutions works, the last resort is to perform a factory reset, which will erase everything on your device. Before you proceed with this method, make sure you have a backup of your device. To do it, go to Settings > General > Reset iPhone.
Method 8: Try a Different Sim Card
Try using a different Sim Card to see if your iPhone has a hardware issue. Remove the old Sim Card from your iPhone and try inserting another Sim Card. If it displays the message, your iPhone might have some kind of hardware issue. In this case, contact Apple.