will a fido sim card work in a koodo phone?

I'm getting a new phone. But the only way i can is if my old koodo phone will be put into use. My mom is with fido and I was wondering if she could replace my koodo sim card with her fido sim card? Is that possible? Will the phone work, or will i have to get it unlocked first?

Yes,it needs to get unlocked...what is your mother's mobile model?If it is a basic mobile model then you can get free unlock code from Unlocking4free.com or approach Simpleunlocking.com and get the required unlock code.Once unlocked you can swap networks....