Making additional mortgage payments reduces your interest costs by shortening the time it takes to pay off your mortgage and lowering your balance along the way.
Paying off your mortgage early can save you tens of thousands of dollars, if not more. Some mortgage lenders will charge penalties for making principal payments early, but those fees are never as high as paying interest on your loan. Making mortgage payments early helps your credit score and builds trust between you and your lender, too.
Just make sure that when you make these payments, they're ear-marked "principal only" or your bank will apply the amount you pay early to the next month's bill, which just gives them their interest payments early instead of eliminating future interest charges. Your regular mortgage payment will be due as usual next month when you make extra principal-only payments.