Which? has revealed whether it is always worth overpaying your mortgage - or if your spare cash could be put to better use elsewhere. You could potentially save thousands of pounds in interest and knock years off your mortgage by making overpayments - but it isn't always the right choice for everyone. Which? has crunched the numbers to see how overpaying, saving and investing compare. The content from Which? is for informational purposes only and is not financial or investment advice. Which?