Start with the amount reaching completion
The headline facility may include retained interest or financed fees. Subtract deductions and any existing-loan redemption to establish the net cash available. The deposit needed can therefore be larger than a simple loan-to-value calculation suggests.
List the cost categories
Interest, arrangement fees, broker fees, valuation, lender legal costs, your legal costs and any exit fee should be shown separately. Check whether VAT applies to any professional charge and whether a minimum interest period applies.
Read the interest method
Serviced interest is paid during the term. Retained or rolled-up interest changes cash available or the balance repaid. The agreement determines whether and how unused interest is returned after early repayment. Do not assume all monthly rate quotations work alike.
Stress the exit date
Ask what happens if sale or refinance is late. Extension, default interest and legal enforcement costs can be substantial. The exit should include the balance, all interest and charges, not just the day-one amount.
Compare an illustrative facility
If a £200,000 gross facility has £12,000 retained interest and £4,000 deducted fees, net funds before other costs are £184,000. This is a hypothetical arithmetic example, not a product quote. Actual terms may calculate interest differently.
Further reading: MoneyHelper: mortgages and homebuying. Content reviewed 9 September 2026. General information; availability depends on the individual case.