First of all, if your SIM card is not working well with your phone, then the first thing you can do is restart your phone. Or reboot your phone.
When you restart your phone, it will refresh your operating system and might fix your problem related to the SIM card not being provisioned.
I am using an AT&T sim card that is not provisioned. How could I fix this error?
Here in this section, we give you a few methods that might fix your problem. And even though your situation does not get fixed, you are good to contact your SIM card company.
Ensure the SIM card is not dirty or wet
While inserting the SIM card into your device, make sure that your SIM card does not have dust on its surface or is not wet either. Dusty and wet SIM cards can even cause trouble recognizing your SIM card in the device. So, dry it before you insert it.
Re-insert the SIM card
Sometimes your SIM card is not provisioned because it may place loosely in your phone. If this is the case, then your phone will constantly throw messages of AT&T SIM cards not provisioned. Remove your SIM card from the device and re-insert it into your phone to fix this issue.
Check whether the SIM card is activated or not
To enjoy the calling and internet service, first of all, check whether the SIM card is activated or not. If you want to enjoy the services, your SIM card must be activated. And if it is not activated yet, contact your carrier and get your SIM card started. Then you could enjoy the services without any interruption.
Try another SIM card slot
Sometimes the errors are visible due to the issues in the slots. If you have a dual smartphone, just try to insert the SIM card into another slot. This may fix your issues.