Last updated: 10 May 2026
By Stiv · Design, technology and personal finance
I've been using Sprive with my Nationwide mortgage since October 2021, making £100 monthly overpayments through the app. This post is based on over four years of real use and real numbers.
Most people know they should overpay their mortgage. Almost nobody knows by how much, or what it actually saves them. So we built a free mortgage overpayment calculator to find out. Then we ran our own numbers through it. The mortgage overpayment savings genuinely surprised us. We've since added a compare-to-savings toggle so you can see whether overpaying or saving the same money comes out ahead at your specific rates.
This article is for informational purposes only and does not constitute financial or mortgage advice. Mortgage products, rates, and overpayment terms vary by lender. Always check your lender's overpayment policy before making extra payments. Your home may be repossessed if you do not keep up repayments. CoolCuration is not authorised by the Financial Conduct Authority.
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