Estimate whether an overpayment or switch could trigger a charge.
Check your remaining overpayment allowance, chargeable repayment amount, estimated early repayment charge, and net amount after fees.
Useful before overpaying
Many fixed-rate mortgage deals allow a limited annual overpayment before an early repayment charge applies.
Estimated total charge
£575
Based on £16,000 above the remaining allowance.
Inputs
Charge details
Estimate
Results
Estimated early repayment charge
£575
Effective cost: 1.64%.
Remaining allowance
£19,000
Chargeable amount
£16,000
ERC only
£480
Net amount applied
£34,425
The admin fee is only included when part of the planned repayment exceeds the remaining allowance.
What to check
Before making the payment
Confirm whether the allowance resets by calendar year, mortgage anniversary, or product year.
Check whether the charge applies to overpayments, full redemption, porting, or switching product.
Ask whether fees are paid upfront, deducted from the payment, or added to the mortgage.
Important disclaimer
This calculator provides estimates only and does not constitute financial advice. Early repayment charge rules vary by lender, product, date, allowance period, and repayment type. Check your mortgage offer or ask your lender before making a real payment or switching deal.