It all depends on the type of mortgage you have and the term. If you have a short term yes the interest rate you pay can change. Look at the terms, like is it 5 years or 10 years or just 1 year and are you locked in with a fixed rate or do you have a variable rate. the broker is the one that should be answering all your questions before you sign. Find out what your signing.
I am a mortgage broker from Edmonton, Alberta. If you have signed the commitment and have a possesion date depending on what mortgage you have the rates may change.for example:5yr closed rate 5.09% ( Your rate is locked in for 5yrs)5yr variable prime - 0.9% (Floating rate dependant on the prime rate - 0.9% locked in for 5yrs usually fixed payments)Amount of money designated to principle and interest varies depending on if the rates go up or down.5yr adjustable rate - 0.9% ( Floating rate dependant on the prime rate - 0.9% locked in for 5yrs usually floating payments)Mortgage payments fluctuate depending on if the rates go up or down. Guaranteed payment of princilpe over term, unpredictable mortgage payments.Sub prime market completely different in Canada to USA. It's more regulated and no as aggressive.If you have any questions, please feel free to contact me at my website Save $1000s with my FREE Canadian Mortgage Newsletter_http://www.albertamortgageguy.com/