Banks are in business to lend money and make a profit by charging interest.
Interest saved on your mortgage is a loss to the Bank. Anything you do to satisfy that rule, will minimize your interest costs. The longer you wait to make a payment towards the principal the larger the interest charge to you. There are a few ways to repay the principal faster but the best method is to pay more frequently and with a payment as large as possible. Weekly and biweekly payment mortgages were introduced in Canada in 1984.