Most UK lenders allow you to overpay up to 10% of your outstanding mortgage balance per year without incurring early repayment charges (ERCs). This means if you owe £200,000, you could typically overpay up to £20,000 annually penalty-free.
However, some lenders offer higher allowances, whilst others may have stricter limits. Fixed-rate mortgages often have more restrictive overpayment terms than variable rates. Always check your mortgage terms or contact your lender to confirm your specific allowances.

This depends on several factors, including your mortgage interest rate, potential investment returns, risk tolerance, and overall financial situation. Generally, if your mortgage rate is higher than the guaranteed returns you can get from savings accounts, overpaying makes financial sense. However, consider maintaining an emergency fund of 3-6 months' expenses first. If you can achieve higher returns through investments (accounting for risk), and you're comfortable with that risk, investing might be more beneficial. Our calculator helps you see the guaranteed savings from overpaying to inform your decision.

Our unique interactive slider lets you explore different overpayment scenarios in real-time without recalculating each time. Simply drag the slider or use the +/-£50 buttons to instantly see how small changes affect your interest savings, time reduction, and monthly payments. The tool compares everything against your original overpayment amount, showing you exactly how much extra you'd save or lose with each adjustment. This makes it easy to find your optimal overpayment level and see whether increasing by just £50 monthly makes a meaningful difference to your mortgage journey.

There are several situations where overpaying might not be the best strategy: if you have high-interest debt (credit cards, personal loans) that costs more than your mortgage rate, it may be better to pay those off first.
If you don't have an emergency fund, prioritise building 3-6 months of expenses in accessible savings.
Also consider if you're planning major life changes (job change, family expansion) that might affect your income or require cash flexibility.

The amount you can save varies significantly based on your mortgage balance, interest rate, remaining term, and overpayment amount. As a general guide, every extra £50 per month typically saves between £3,000-£5,000 in interest over the life of your mortgage. For example, on a £200,000 mortgage at 4.5% with 18 years remaining, overpaying £300 monthly could save around £25,000 in interest and reduce your term by approximately 5 years.
Our interactive calculator shows your specific savings instantly.