Interest-only mortgage ending soon: calculate the capital repayment gap

An interest-only mortgage can reach the end of its term with the original capital still outstanding, even when every monthly interest payment has been made. The immediate question is whether the resources intended to repay it will be sufficient and available on time.

Obtain the lender's current balance and term-end date, then compare them with realistic net proceeds from the repayment plan. If a gap appears, discuss it with the lender early rather than relying on a future extension being available.

Separate the monthly payment from the final debt

MoneyHelper explains that interest-only payments cover interest while a separate plan is needed for the capital. Regular payment history does not mean the original borrowing has gradually reduced.

Ask whether any part of your mortgage is on a repayment basis and whether capital overpayments have changed the balance. Obtain a statement of what will fall due, including any fees relevant to the planned repayment date.

Keep the end of the mortgage term separate from the end of a fixed-rate deal. A rate change may occur before the capital repayment date, creating a different cashflow issue.

Value the repayment resources realistically

For each proposed source, record its current value, expected net proceeds, access date and uncertainty. An investment projection is not a guaranteed redemption amount, and a property valuation is not money already in the bank.

Pension resources need particular care. Confirm access eligibility, the payment route, any tax and the income left for retirement. The whole pension balance should not be entered as tax-free cash available to clear a mortgage.

Do not assign the same savings to both mortgage repayment and essential retirement spending. A plan can appear balanced twice on paper while relying on one pot of money.

Calculate an illustrative shortfall

Assume £120,000 of mortgage capital falls due in four years. Suppose £42,000 is already in cash specifically allocated to repayment and an investment is currently worth £38,000. On today's values, there is £80,000 available before any relevant costs or tax, leaving a £40,000 gap.

Ignoring returns, charges and inflation, saving £40,000 over 48 months requires approximately £833.33 a month, with a small final adjustment for rounding. This gives a starting affordability test, not a promise that the plan will succeed.

If the £38,000 investment instead falls by 20%, it becomes £30,400 and the gap increases to £47,600. This is a stress example, not a forecast. It shows why a repayment plan needs more than an assumed positive growth rate.

Discuss options with the lender before committing

Ask about permitted capital overpayments, conversion to repayment or part repayment, and any possible term change. Availability depends on the lender and your circumstances; none should be assumed from a general guide.

Request written figures showing the new monthly payment, fees, total term and remaining capital. A lower payment achieved by extending the term can also mean paying interest for longer.

If another lender is being considered, a mortgage adviser can explain the market and relevant affordability assessment. An investment adviser may help assess the assets intended to repay the debt. Confirm which part of the problem each professional is addressing.

Make a property-sale plan concrete

If selling or downsizing is the repayment strategy, estimate the proceeds after the mortgage, selling costs and the cost of the next home. Include moving expenses and any applicable property taxes.

For an invented example, a £400,000 sale less £120,000 mortgage redemption and £12,000 selling and moving costs leaves £268,000 before buying somewhere else. If the replacement home and purchase costs require £275,000, the plan still has a £7,000 gap.

Use realistic prices and timing, with a contingency if the sale takes longer. Equity on a valuation statement is not proof that a suitable replacement home can be bought within the remaining amount.

Review investment risk as the date approaches

A repayment date creates a specific cash requirement. Ask how the plan would respond to a market fall shortly before funds must be realised, and whether transaction or settlement timings create another delay.

This does not mean every investment should be sold immediately. Changing holdings can have costs and tax consequences. It means that the investment strategy and the mortgage deadline must be considered together rather than reviewed independently.

Keep updated values and lender correspondence in one file. A plan based on an old endowment projection or outdated mortgage balance can conceal a growing mismatch.

Seek help promptly if the plan is not affordable

If payments or final repayment are becoming unmanageable, contact the lender and a free debt-advice service. Avoid ignoring the issue while waiting for markets, house prices or an uncertain inheritance to solve it.

Related guides explain financial advisers versus mortgage brokers, planning before retirement and advice after selling property. A useful next conversation starts with the amount due, the date and the evidenced repayment resources.