A mortgage is likely the largest financial commitment you'll ever make. Over a 25 or 30-year term, the interest alone can often equal nearly half the original amount borrowed. However, there is a powerful tool at your disposal that many homeowners overlook: the overpayment.

How Overpayments Work

When you make your regular monthly mortgage payment, part of it goes toward the interest charged for that month, and the rest pays down the "principal" (the amount you actually borrowed). In the early years of a mortgage, the interest portion is much larger.

By making an overpayment, you are paying off the principal directly. This reduces the balance on which interest is calculated for every single month for the rest of your mortgage term. It creates a compounding effect in your favour.

The "10% Rule"

Most lenders allow you to overpay by up to 10% of your outstanding balance each year without penalty. If you exceed this, you may be charged an Early Repayment Charge (ERC). Always check your specific mortgage terms before making large lump-sum payments.

Case Study: The £100 Strategy

Imagine a £250,000 mortgage at a 5% interest rate with 25 years remaining. By overpaying just £100 per month, you would:

• Save over £25,000 in interest.
• Reduce your mortgage term by over 3 years.

Is it better than saving?

This is the most common question. Mathematically, if your mortgage interest rate is higher than the interest rate you can earn in a savings account (after tax), you are better off overpaying your mortgage. It provides a "guaranteed return" equal to your mortgage rate.