Last updated: 9 June 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 took us by surprise. 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. This article contains affiliate or referral links. If you click through and sign up I may earn a commission or referral bonus at no extra cost to you. It does not affect my editorial view. Your home may be repossessed if you do not keep up repayments on your mortgage. CoolCuration is not authorised by the Financial Conduct Authority.
See your own overpayment savings
Our free calculator shows what your overpayments could save, and whether saving the cash instead would beat them.
Open the overpayment calculator
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