Mortgage Fee Comparison Calculator
Compare two mortgage deals over one chosen period. Interest plus fees and remaining debt help distinguish a cheaper deal from merely a smaller payment.
Rule year: 2026/27 · GBP · Sources checked
Deal A interest and fee cost in comparison period
Two fixed-rate repayment deals with constant entered rates over a common period within the loan term. One arrangement fee each, supplied treatment and monthly amortisation. No valuation/legal fees, ERC, cashback, follow-on rate forecast, lender eligibility or discounted value of upfront cash. Costs outside the period are excluded.
Repayments, fees and debt at the comparison date
Interest plus fees compares financing cost, including interest on financed fees. Principal repayments are not a cost. Remaining balance prevents a lower payment from hiding extra debt.
| Deal | Paid repayments | Upfront fee | Ending debt | Interest plus fee |
|---|---|---|---|---|
| A | £32,015.95 | £999.00 | £229,122.26 | £22,137.21 |
| B | £32,673.33 | £0.00 | £229,417.79 | £22,091.12 |
For informational purposes only. This estimate is not financial advice, a tax return, a payroll calculation or a lender decision. See the supported circumstances and exclusions below.
How this calculator works
A low-rate mortgage with a large arrangement fee can cost more over a short deal period than a higher-rate fee-free offer. This comparison uses the same underlying principal, repayment term and comparison horizon for both offers. Financing a fee increases debt and adds interest; paying it upfront leaves principal unchanged. Interest plus fee measures financing cost in the period, while the table also shows repayments and remaining debt. Principal repayment is not counted as a cost, so a payment difference cannot hide a different ending balance.
Formula and rules
Deal period cost = interest accrued during common comparison period + arrangement fee. Financed principal = underlying loan + financed fee. Cost difference = Deal B period cost − Deal A period cost.
Assumptions and limitations
Two fixed-rate repayment deals with constant entered rates over a common period within the loan term. One arrangement fee each, supplied treatment and monthly amortisation. No valuation/legal fees, ERC, cashback, follow-on rate forecast, lender eligibility or discounted value of upfront cash. Costs outside the period are excluded.
Worked example
Two zero-rate offers on a £240,000 loan over 20 years have no period interest. Paying a £1,000 fee upfront makes Deal A cost £1,000 over two years; a fee-free Deal B costs £0. Financing the fee changes payment and ending debt.
- Deal A interest and fee cost in comparison period
- £1,000.00
- Deal B interest and fee cost in comparison period
- £0.00
- Deal B minus Deal A comparison-period cost
- -£1,000.00
- Deal A monthly repayment
- £1,000.00
Official sources and review
Reviewed against the sources below on 2026-10-06. Rates are held in versioned rule modules. Versioned rules, official source review and year-specific calculation tests.
- MoneyHelper: Mortgage fees and costs ↗
Arrangement fees may be financed; comparing repayments alone can miss upfront costs.
- MoneyHelper: mortgage overpayments ↗
Lenders set overpayment allowances and early repayment charges. Contract terms, not a universal 10%, govern.
Common questions
Why compare interest plus fees instead of repayments alone?
Repayments include principal that reduces debt. Interest plus fees measures financing cost, and the ending balance reveals remaining debt.
Does adding the fee to the mortgage change the result?
Yes. It raises principal and can add interest during the comparison period. The table shows the resulting payment and ending debt.
Can I compare deals with different fixed periods?
Use a common horizon during which both entered rates apply. Follow-on rates or future remortgage costs require separate scenarios.