Do biweekly or extra principal payments really pay off my mortgage faster?

Yes – any payment above what's required goes straight to principal and shortens the loan. With biweekly payments you make half your payment every two weeks, which works out to 26 half-payments, or 13 full payments a year instead of 12. That one extra payment annually can knock roughly four to six years off a 30-year mortgage and save tens of thousands in interest. You can replicate this for free by adding one-twelfth of your payment to principal each month – no special program needed. Tell your servicer to apply extra amounts to principal, not next month's payment. Before accelerating, make sure you've funded your emergency reserve and captured any employer 401(k) match, since those usually beat a mortgage rate.