Thinking of leaving your fixed-rate mortgage early? Enter your current deal and a new rate to see whether the interest savings outweigh the Early Repayment Charge — with a clear break-even verdict.
When mortgage rates fall, borrowers still locked into a higher fixed deal face a tempting question: is it worth paying the Early Repayment Charge to jump onto a cheaper rate now? The answer hinges on three numbers — how much lower the new rate is, how long is left on your current fix, and the total cost of switching (the ERC plus valuation and legal fees).
This calculator settles it by finding your break-even point. It amortises both your current mortgage and the new deal — adding the switching costs onto the new balance, as most lenders do — while keeping your monthly payment the same. Each month it tallies the interest you'd save on the cheaper rate. The month that running total overtakes your switching cost is the moment the switch has paid for itself.
Reading the verdict
If you break even comfortably before your current fix ends, switching is usually worth serious consideration — and because you keep paying the same amount, the lower rate also shortens your term. If break-even lands after the ERC period, or the numbers never recover the cost, the calculator flags it clearly. Either way, treat this as a starting point and confirm the details with an FCA-regulated mortgage adviser before acting.
Frequently Asked Questions
An ERC is a fee your lender charges if you leave a fixed-rate deal before it ends. It's usually a percentage of your outstanding balance — often 1–5%, typically stepping down each year. On a £200,000 balance a 2% ERC is £4,000.
It depends on how much lower the new rate is, how much time is left on your fix, and total switching cost. This calculator finds your break-even point — where cumulative interest savings exceed the switching cost. Break even well before your fix ends and it's usually worth considering.
The tool amortises both your current mortgage and the new deal (with switching costs added) using your existing monthly payment, comparing the interest paid each month. When the running total of interest saved exceeds the total switching cost, you've broken even.
Yes. This calculator is indicative only and uses generalised amortisation rules. Your exact ERC, product fees and eligibility depend on your lender. Always speak to a qualified, FCA-regulated mortgage adviser before deciding.
Disclaimer: This calculator is indicative only and based on generalised amortisation rules. It does not constitute financial or mortgage advice. Your actual ERC, fees and eligibility depend on your lender and circumstances. Always consult a qualified, FCA-regulated mortgage adviser before making any decision about your mortgage.