Interest-Only vs Repayment Mortgages: What Happens at the End of the Term

The choice between interest-only and repayment mortgages fundamentally changes what happens at the end of your term - and interest-only mortgages, in particular, come with a specific obligation that’s easy to underestimate at the start. Here’s what each actually means.

The core difference

• Repayment mortgage: your monthly payment covers both interest and a portion of the capital borrowed, so the loan is gradually paid down and reaches zero at the end of the agreed term. This is now the standard, default type for most residential mortgages, including those arranged through guarantor or family deposit schemes.
• Interest-only mortgage: your monthly payment covers only the interest - the capital you originally borrowed remains completely unchanged throughout the term, and you must repay the full original loan amount as a lump sum at the end.

Why interest-only payments look deceptively low

Because you’re only paying interest, monthly payments on an interest-only mortgage are meaningfully lower than an equivalent repayment mortgage - but this doesn’t mean the mortgage is cheaper overall; it means the capital repayment is being deferred entirely to the end of the term, when the full original loan amount falls due in one go.

What you need at the end of an interest-only term

You need a credible repayment vehicle - a plan for how you’ll pay off the full capital when the term ends. Common approaches include an investment portfolio (such as a Stocks & Shares ISA) built up specifically for this purpose, selling the property itself (relying on it retaining or growing in value), or downsizing. Lenders are required to check you have a credible plan before approving an interest-only mortgage, and increasingly scrutinise this more carefully than in the past, following historical cases where borrowers reached the end of their term with no viable way to repay the capital.

Why interest-only mortgages have become harder to get

Following regulatory tightening after the 2008 financial crisis (when a significant number of interest-only mortgages had been sold without robust repayment plans), lenders are now considerably more cautious, generally requiring proof of a specific, credible repayment vehicle rather than simply hoping property values rise enough to cover the gap. This has made pure interest-only mortgages less common for standard residential purchases, though they remain more common in buy-to-let lending, where the rental income itself is treated differently in the affordability assessment.

Repayment mortgages: the default, and why

For most residential borrowers, a repayment mortgage is now the standard recommendation - you know with certainty that the mortgage will be fully paid off by the end of the term, without needing a separate repayment vehicle or plan. The Mortgage Guarantee Scheme (covering 95% deposit mortgages) explicitly only supports repayment mortgages, not interest-only, reflecting this general regulatory preference for residential lending.

A middle-ground option: part-and-part

Some lenders offer a part interest-only, part repayment structure, splitting your mortgage so a portion behaves like a repayment mortgage (gradually paying down) while the rest is interest-only (requiring a repayment vehicle at the end). This can suit borrowers who want lower monthly payments than full repayment but a smaller, more manageable capital sum due at the end than a fully interest-only mortgage would leave.

If you already have an interest-only mortgage nearing its end

• Review your repayment vehicle’s actual value now, well before the term ends, rather than assuming it will be sufficient without checking.
• Speak to your lender early if there’s a shortfall - options may include extending the term, switching part of the mortgage to repayment for the remaining years, or other restructuring, but these need time to arrange.
• Consider downsizing as a legitimate, planned repayment strategy if other options fall short, rather than as a last-minute forced decision.

The bottom line

A repayment mortgage guarantees the loan is paid off by the end of the term; an interest-only mortgage requires a credible, separately funded plan to repay the full capital at that point - and lenders now scrutinise this plan carefully before approving one. If you’re on interest-only, checking your repayment vehicle’s actual progress well ahead of the term ending is essential, not optional.