I got a message "NO SIM" not working my sim card.

Hi, there

First,  I’m not in Canada right now. but I didn’t roam or stop using the phone when I come back to Canada.

Also, I’m paying the bill as well.

When I Came to outside Canada I took sim out from my cell phone cause of roaming automatically.

Today, I need to get some my bank code number from text, so I put sim card into the cell phone.

But sim is not working “ NO SIM”      I don’t know what happen?

Could you tell me why sim card is die? Even not in canada now, I keep my cell phone number and paid the bill out all thing  in KOODO, 

Thanks

All The best, 

Dan