This problem often occurs when you turn your smartphone off and on again, insert a new SIM card, or, in some cases, while using your phone, when your SIM card is suddenly undetected.

If your phone suddenly won't recognize your SIM card, don't panic. There are a few things you can do to try and resolve the problem. Here's what to do.

A SIM card is a small chip you insert into your phone to connect to a cellular network. Provisioning simply means activating or configuring the SIM so it can access the network’s services.

Fortunately, it’s usually a quick and straightforward problem to solve – we’ll guide you through each step individually so you can easily get your phone working again in no time!

If you have a traditional single SIM phones, try something simple like pulling your SIM card and blowing on it, wiping it down a little, and plug it back in. See if that will re-establish connection.

If it were a loose connection causing the problem, this step can solve it. Test the card with other phones and see if it works. If it does, then there isn’t a problem with it, it’s the phone.

If you have switched SIM cards in recent days, it is possible one of them has been lost or damaged while being removed from the slot in your phone's battery door. How to fix the problem?

These 5 possible methods will help you to solve your Android phone's Connection problem or invalid MMI Code issue in a jiffy.