You can sell your property at anytime with a 5 year fixed mortgage. When you sell and buy another property you can port your mortgage from the previous home to the new one. This is a simple process and has no penalties in doing so.

If you sell your home and break the mortgage you will most likely going to pay a penalty which might be a percentage of the left amount of mortgage or 3 month mortgage payments. It is all depends on your mortgage condition and you can call the bank to verify what it is.

Penalties vary between different lenders but I think its 3 month of mortgage payments to break a mortgage in most cases. You should ask your bank how much is the penalty to break the mortgage sooner.