Apple

I’m in Canada where I think things are different then other countries for phone plans. I have a super cheap plan right now for $50 a month which is no longer available if I upgrade my device through any provider. I’ve never done it before but I was wondering if I buy my phone outright can I simply put my old SIM card in the new phone and still only pay $50 for my plan??

It may be a super stupid question or not, I’m not sure. But I’ve never heard of any of my friends doing this but that being said I can’t see why it wouldn’t work?

Thanks for the advice!