Most UK mortgages fix the interest rate for two or five years. A small number of lenders offer fixes lasting decades — locking the rate for the whole term of the loan, as is common in the US, Denmark and parts of Europe.

This article explains how long-term fixes work and the trade-offs involved.

Your home may be repossessed if you do not keep up repayments on your mortgage.

Two different things: term length vs. fix length

These are often confused, and the distinction matters.

Mortgage term is how long you take to repay the loan. Stretching a repayment mortgage from 25 to 40 or 50 years lowers the monthly payment but increases total interest substantially.

Fix length is how long your interest rate stays locked. A long fix removes the risk of your payment rising, and removes the need to remortgage every few years.

A long-term fixed rate mortgage generally combines both — a long term and a rate fixed for most or all of it.

What happened to the 50-year mortgage?

In August 2022, a new lender called Perenna received a restricted UK banking licence, with plans to offer fixed rates lasting up to 50 years. The coverage at the time focused on that headline figure. Perenna's model was unusual: rather than funding mortgages from customer deposits like a high-street bank, it issues covered bonds to pension funds and insurers, which allows it to lend at a rate fixed for decades.

Perenna received full authorisation in September 2023 and began lending that October. But the 50-year product never launched. As of 2026, Perenna offers fixed rates of 5 to 10 years — long by UK standards, where two and five-year fixes dominate, but far from the original ambition.

It wasn't alone in retreating. Several lenders entered the long-fix market around 2021:

• Habito launched Habito One in March 2021, with fixes from 10 to 40 years and no early repayment charges on part of the range. It withdrew its mortgage products during the market disruption following the September 2022 mini-budget. Habito was acquired by Monzo in December 2025.

• Kensington Mortgages launched Flexi Fixed for Term in November 2021, offering fixes from 11 to 40 years, funded by the pensions insurer Rothesay. Kensington was acquired by Barclays in 2023.

• Molo Finance offered FlexLife, a 15 to 40-year fix, before pausing lending in 2022.

The common factor was timing. These products launched when rates were near historic lows and were designed to appeal to borrowers worried about rises. When rates then rose sharply through 2022 and 2023, the economics changed for both lenders and borrowers — long fixes at higher rates were less attractive to buyers, and harder for lenders to fund.

The UK market has largely returned to shorter fixes. Availability in this part of the market changes, so it's worth checking directly with a broker which long-term products, if any, are currently open to new applications.

How much does a longer term reduce payments?

The effect is significant on the monthly payment and substantial on the total cost.

On a £478,000 loan (90% of a £531,000 property) at 5.35%:

The monthly saving is around £600. The additional interest over the full term is around £506,000 — more than the original loan.

That trade-off is the central question with any long-term mortgage: a lower payment now, at a considerably higher lifetime cost.

Arguments in favour (of a longer fixed mortgage)

Lower monthly payments. Spreading repayment over a longer period reduces what's due each month, which can make a purchase possible that otherwise wouldn't be.

Payment certainty. With the rate fixed for the term, the payment doesn't change. There's no remortgaging every few years, no product fees each time, and no exposure to rate rises.

Inflation erodes the payment in real terms. A fixed payment becomes a smaller share of income over decades, assuming wages rise.

You own the property at the end. Unlike an interest-only mortgage, a long-term repayment mortgage clears the debt, leaving the borrower owning the home outright.

Arguments against

Much higher total cost. As the table shows, the additional interest over a 50-year term can exceed the original loan.

Repaying into retirement. A mortgage taken at 30 on a 50-year term runs to age 80. Whether that's affordable depends on pension income.

Slower equity building. More of each early payment goes on interest, so equity accumulates more slowly — which matters for moving, remortgaging, or if prices fall.

What happens on death. If one borrower on a joint mortgage dies, the survivor may struggle with the payments alone. Where a property is inherited, the debt goes with it.

Possible effect on prices. Some argue that increasing what buyers can borrow pushes prices up rather than making housing more affordable, leaving buyers with larger loans against the same properties.

Early repayment charges. Long fixes often carry ERC periods. An early repayment charge (ERC) is a fee a lender charges if you pay off some or all of your mortgage before the end of the deal period. The ERC period is the window during which that charge applies.

Overpayments

Many long-term mortgages allow overpayments, sometimes without charge. Overpaying shortens the term and reduces total interest, which can substantially soften the main drawback. The overpayment allowance is worth checking before committing.