Received an alert that says Invalid SIM or No SIM Card installed? If so, follow these steps:
Firstly, restart your device.
Check for a network provider settings update. Go to Settings > General > About. If an update is available, you'll see a prompt to select OK or Update.
Get in touch with your network provider to ensure your SIM has not been blocked.
Remove the SIM card from the SIM card tray and then put the SIM card back. Make sure the SIM tray closes completely and isn’t loose. If you use a SIM tray from a different model, it may not fit properly.
Try another SIM card to see if the issue is with the device or the SIM.
If you have completed the steps but are still experiencing an issue, please get in touch for further help.