Interest-Only Mortgages
An interest-only mortgage keeps your monthly payments considerably lower by covering just the interest – but the full amount you originally borrowed remains outstanding, in full, until the day the mortgage ends. Understanding exactly what lenders need to see before agreeing to this structure matters more than the appeal of a lower monthly payment.
How Interest-Only Actually Works
Each monthly payment covers only the interest charged on your loan, meaning the capital balance stays exactly the same throughout the entire term. At the end of the mortgage, the full amount originally borrowed is still owed, and needs to be repaid in one lump sum – there’s no gradual reduction happening in the background the way there would be with a standard repayment mortgage.
Why You Need a “Repayment Vehicle”
Before agreeing to an interest-only residential mortgage, lenders require credible evidence of exactly how you plan to repay the capital at the end of the term – this is called a repayment vehicle, and it’s a genuine requirement, not a formality. Simply hoping something will come up, such as an inheritance or a future windfall, generally isn’t accepted as a credible plan.
What Lenders Actually Accept as a Repayment Vehicle
Common, genuinely accepted repayment vehicles include the sale of a second property, such as a buy-to-let or holiday home, stocks, shares, and other investments, a pension lump sum, and in some cases the sale of your main residence itself, though this specific option often comes with its own minimum equity requirements and isn’t always accepted in combination with other strategies.
Investments and Stocks
If you’re relying on stocks, shares, or a broader investment portfolio, lenders typically apply a discount to the current value – commonly assessing it at somewhere between 50% and 90% of today’s value, to account for genuine market uncertainty over the years ahead.
Pension Lump Sums
Under current UK pension rules, you can typically take up to 25% of a defined contribution pension pot as a tax-free lump sum from age 55, rising to 57 from 2028. Many lenders will accept this as part of a repayment vehicle, provided the projected value genuinely covers what you’ll owe.
Cash Savings and ISAs
Some lenders no longer accept cash savings or ISAs as a sole repayment vehicle, though they can still form part of a broader combined strategy alongside other options.
Why Endowment Policies Fell Out of Favour
Endowment policies were once the standard repayment vehicle for interest-only mortgages, but many underperformed their original projections in the 1990s and 2000s, leaving a genuine number of borrowers with a real shortfall at term end. This history is exactly why lenders now scrutinise repayment vehicles so much more rigorously than they once did, and why very few still accept endowment policies at all.
Selling the Property Itself
Using the sale of your main residence as your repayment vehicle is accepted by some lenders, though typically with a genuine minimum equity requirement, commonly in the region of £200,000-£300,000, and it’s often the only strategy that can’t be combined with other repayment vehicles.
Loan-to-Value and Deposit
Interest-only residential mortgages are typically capped at a lower loan-to-value than standard repayment mortgages, commonly around 75%, meaning you’ll generally need a deposit of at least 25%. Some lenders apply minimum income requirements specifically for interest-only applications, on top of the standard affordability assessment.
Buy-to-Let Is Genuinely Different
Most buy-to-let mortgages are arranged on an interest-only basis by default, and the assessment is genuinely different to a residential interest-only mortgage – the repayment vehicle is simply the eventual sale or refinance of the rental property itself, with affordability assessed against rental income rather than the rigorous personal repayment vehicle scrutiny that applies to residential borrowing. Our Buy-to-Let Mortgages page covers this in more detail.
Part and Part: A Middle-Ground Option
Some lenders offer a part and part structure, where a portion of your monthly payment covers capital as well as interest, and the remainder stays interest-only. This reduces the eventual lump sum owed at term end compared with a fully interest-only mortgage, while keeping monthly payments lower than a full repayment mortgage would require.
Reviewing Your Repayment Vehicle Over Time
It’s worth reviewing your repayment vehicle at least annually, since investment performance and personal circumstances genuinely change over the life of a mortgage. Most lenders will proactively contact you to check your plan remains on track, but it’s worth doing this yourself too, since catching a genuine shortfall early gives you considerably more options than discovering it close to term end.
If Your Repayment Vehicle Falls Short
If your chosen strategy isn’t tracking toward covering the full balance, options generally include increasing your contributions, extending the mortgage term, switching to a part and part or full repayment structure, or in some cases downsizing. It’s worth speaking with your broker as soon as you have genuine concerns, rather than waiting until the mortgage is close to maturing. Our Interest-Only Mortgage Term Ending page covers this specific situation in more detail if your term is genuinely approaching its end.
Later Life Interest-Only: A Different Product Entirely
If you’re specifically looking at interest-only borrowing later in life, with no fixed end date and repayment tied to death, moving into care, or sale of the property, our Retirement and Later Life Mortgages page covers Retirement Interest-Only products, a genuinely different structure to a standard term-limited interest-only mortgage.
Frequently Asked Questions
What happens if I can’t repay the capital at the end of an interest-only mortgage?
You risk needing to sell the property, or your lender may consider extending the term, switching you to a repayment basis, or another solution, depending on your circumstances.
Can I use my savings as a repayment vehicle?
Some lenders no longer accept cash savings or ISAs alone, though they can often form part of a combined strategy alongside other repayment vehicles.
What deposit do I need for an interest-only mortgage?
Typically at least 25%, since interest-only lending is commonly capped around 75% loan-to-value.
Is buy-to-let interest-only assessed the same way as residential?
No – buy-to-let interest-only is typically assessed on rental income and the eventual sale of the property, rather than the personal repayment vehicle scrutiny applied to residential borrowing.
Can I switch from interest-only to a repayment mortgage later?
Often yes, though this increases your monthly payment, and you generally can’t switch back to interest-only again afterward with the same lender.
Get in touch with details of your circumstances and repayment plans, and we’ll help you understand whether an interest-only mortgage genuinely suits your situation.
