You can make an extra mortgage payment every year by paying half the monthly bill every other week. Some lenders allow this practice. When a lender does not accommodate, simply put aside half the total payment every two weeks, and pay the excess of the set amount when available.
Another way to make an extra mortgage payment is to include an additional monthly sum. Any dollar amount supplementary to the set monthly mortgage payment immediately decreases the principal on the mortgage.
Lenders calculate the interest on a mortgage from the principal balance. Lower principal nets less interest. Chipping away at the principal, especially early in the mortgage contract when interest is highest, saves money.