What about stepped ERCs?

Many deals charge a higher % in year 1 and less later. Enter the % that applies now, or run the estimator once per step. Always check offer wording.

Enter the amount you plan to repay early. The estimate scales the ERC to that portion for simple %-of-balance and interest methods.

Do product transfers charge an ERC?

Often not, because you are not fully redeeming. Confirm it on the retention offer.

Can I avoid the ERC by waiting?

Usually it falls away on the deal end date. Waiting can still mean a higher SVR.

Is this what my lender will bill?

No. Ask for a redemption statement.

Early repayment charge calculator (UK mortgage ERC)

Last checked 2 November 2026UK · illustrative onlyNot a lender or brokerAbout Disclaimer

Published by Rodway Labs — not a mortgage adviser

Work out how much an early repayment charge (ERC) could cost if you leave your mortgage deal early, using a percentage of the balance or N months’ interest. Always check your offer wording — lenders use different (and sometimes stepped) methods. Starters match the site EXAMPLE (2% of £185,000 = £3,700).

Equations and method

Assumptions

Supports % of balance and months-of-interest methods. EXAMPLE default: 2% of £185,000 = £3,700.
Does not cover all stepped schedules, deed quirks, or cashback clawback.
Interest method uses your entered current rate on the full balance before scaling.
Check offer wording — this is an estimate only.

Your inputs

Starter figures are UK EXAMPLE values you can edit. Scenario rates, not a market quote. 4.19%, 4.39%, 4.14% and 7.49% SVR on this site are labelled EXAMPLE figures, last checked 2 November 2026. Results update as you type.

Outstanding balanceEXAMPLE £185,000

ERC method

PercentageCheck offer wording

Amount redeeming earlyLeave 0 for full balance

Always check your mortgage offer wording — lenders use different (and sometimes stepped) ERC methods.

Results

Method

2% of redeemed balance

Amount assessed

£185,000.00

Estimated ERC

Check offer wording

£3,700.00

Effective % of full balance

2.00%

Check your offer wording for the exact ERC formula, stepped rates, and any overpayment allowance before redeeming or remortgaging.

Method: 2% of redeemed balance. % method uses redeemed amount × percent; interest method uses (rate÷12) × balance × months (scaled for partials). Check offer wording before relying on this estimate.

Illustrative only — not personalised advice, not a credit or mortgage offer, and not an FCA-regulated recommendation. Your offer and ESIS set the real ERC, fees and terms. Full calculator disclaimer.

What to do next

How to use this calculator

Enter the outstanding balance from your latest statement or redemption figure.
Pick the ERC method your offer uses: a percentage of the amount repaid, or a number of months' interest.
Enter the percentage or number of months, and your current annual rate if the method is months of interest.
Enter the amount you would repay early. Leave it at the full balance for a remortgage, or lower it for a partial overpayment.
Check the estimated ERC against your lender's redemption statement, which is the figure that actually applies.

Methodology and equations

% method: ERC = redeemed amount × (percent ÷ 100). Interest method: ERC ≈ (annual rate ÷ 12) × full balance × months, scaled by redeemed ÷ balance for partials.

The assumptions are listed in the box near the top of this page.

How this calculator works

Use this to turn the ERC clause in your offer into a sterling figure before you compare rates. The clause wins over this estimate.

How this is calculated

Percentage method: amount repaid × the percentage in your offer. If you leave the “amount repaid” box at 0, the whole balance is used.
Months-of-interest method: (current rate ÷ 12) × balance × number of months, scaled down by the share of the balance repaid.
Effective percentage = the ERC ÷ the full balance, so a partial repayment can be compared with a full one.

This matches the code behind the tool. The full formulae are on the calculator methodology page.

Worked example

Scenario rates, not a market quote

EXAMPLE: £185,000 at 2% of balance is £3,700. That is the figure used across this site when the EXAMPLE ERC is still live.

Months-of-interest on the same balance at EXAMPLE 4.19% for 3 months is about £1,938. Your offer may use a different rate. Last checked 2 November 2026.

Partial repayment on the same EXAMPLE: repaying £50,000 at 2% gives £1,000, which is 0.54% of the full £185,000 balance. Whether a partial repayment is charged at all depends on your overpayment allowance.

Limitations: what this ignores

Overpayment allowances, unless you reduce the balance first.
Redemption admin fees.
Cashback clawback.
The exact balance date in the offer.

Sources

Guides that go with this tool

Questions

Is an ERC the same as an exit fee?: No. You can owe both.
Do product transfers charge an ERC?: Often not, because you are not fully redeeming. Confirm it on the retention offer.
Can I avoid the ERC by waiting?: Usually it falls away on the deal end date. Waiting can still mean a higher SVR.
Which method should I pick?: The one written in your offer.
Is this what my lender will bill?: No. Ask for a redemption statement.

Notes & FAQs

What about stepped ERCs?: Many deals charge a higher % in year 1 and less later. Enter the % that applies now, or run the estimator once per step. Always check offer wording.
Partial redemptions: Enter the amount you plan to repay early. The estimate scales the ERC to that portion for simple %-of-balance and interest methods.