Breaking a mortgage means paying it off early, changing terms, or ending the contract, often incurring penalties. Open mortgages have no fees, but closed fixed-rate mortgages require paying three months' interest or the interest rate differential, whichever is higher. Variable-rate mortgages usually incur a three-month interest penalty. Additional fees may apply. Strategies to reduce penalties include making maximum prepayments, porting the mortgage, blending and extending rates, or having the buyer assume the mortgage. Careful calculation is essential before deciding.