A homeowner is on course to save £18,000 in mortgage interest and pay off his loan more than two years early. His approach uses everyday spending to help tackle the debt as borrowing costs rise.Ben Byrne, 24, from Redditch, bought his second property for £292,000 in September 2025, taking out a £248,200 mortgage.A year later, he discovered Sprive, a free cashback app that helps homeowners make mortgage overpayments.Cashback earned through his fo…