Your mortgage rate
The higher the mortgage rate, the stronger the case for overpaying can become because the interest saving is more noticeable.
If you have spare cash, the practical question is whether it does more for you reducing mortgage interest or staying available in savings.
Direct answer
Overpaying can make sense when your priority is reducing mortgage interest and becoming mortgage-free sooner. Saving may make more sense when flexibility, emergency access, or stronger savings rates matter more than reducing the balance straight away.
A simple decision often comes down to a few practical factors.
The higher the mortgage rate, the stronger the case for overpaying can become because the interest saving is more noticeable.
Money used for an overpayment is locked into the mortgage, while savings stay available if life changes unexpectedly.
Before overpaying, check the 10% rule and early repayment charges so the saving is not reduced by fees.
Test the outcome and compare it against your mortgage terms.
A simple rule of thumb still needs a real-world check.
This comparison gives a planning view rather than a personal recommendation. The better option depends on your own rate, cash buffer, and how much flexibility you want to keep.
Run the calculator to see what a realistic overpayment could save, then compare that outcome with the value of keeping the cash aside.