Retirement Interest Only Mortgages (RIO) Explained UK 2026

Retirement interest only (RIO) mortgages are designed for older borrowers who want to keep monthly costs low without letting the debt balloon. Here is how they work in 2026 and how they compare to equity release.

What a RIO mortgage is

With a RIO you pay only the interest each month, and the original loan amount stays the same. The capital is repaid in full when a defined event happens, usually when you:

• Die
• Move into long-term care
• Sell the property

Because you pay the interest monthly, the balance does not grow, unlike a rolled-up lifetime mortgage.

How it differs from equity release

People often confuse RIO mortgages with equity release, but they behave differently.

• RIO mortgage: you pay interest monthly, the debt stays level, and you must prove you can afford the payments from retirement income.
• Lifetime mortgage (a form of equity release): you can let the interest roll up, so the debt grows over time and erodes more of the home's value.

A RIO can therefore preserve more inheritance, provided you keep up the monthly interest, but it requires ongoing affordability.

Who can apply

RIO mortgages are aimed at older borrowers, often from around age 55. The key test is affordability based on your pension and other retirement income, not just the value of the property. Lenders will check that you can sustain the interest payments for the long term, including after a partner has died if income would drop.

Worked example

Suppose you have a GBP 120,000 RIO mortgage at an illustrative 5% interest rate.

• Annual interest: 5% x GBP 120,000 = GBP 6,000
• Monthly interest: GBP 6,000 / 12 = GBP 500

You pay GBP 500 a month and the GBP 120,000 balance never changes. When the home is eventually sold, that GBP 120,000 is repaid and the rest of the value goes to your estate. The actual rate you are offered will vary, so always work from your own quote.

Pros and cons to weigh

• Lower monthly cost than a repayment mortgage, since you only pay interest
• Debt stays level so more equity can be preserved for inheritance
• Affordability tested on retirement income, which not everyone will pass
• The home is at risk if you cannot keep up interest payments
• Interest is paid for life, which over many years can total a large sum

Alternatives to consider

• Downsizing to a smaller home to release cash without a new loan
• A standard repayment mortgage if you have enough income and term
• A lifetime mortgage if you cannot meet monthly affordability, accepting that the debt will grow

Getting it right

RIO mortgages can suit borrowers who want predictable low payments and a level debt, but the affordability test and lifelong interest mean they are not for everyone. Independent later-life mortgage advice is strongly recommended.

To estimate the monthly interest on a given balance and rate, use the CalcHub mortgage calculator, and read the official guidance on later-life borrowing and equity release at gov.uk and the Money Helper service.