Long-term fixed-rate mortgages

A long-term fixed-rate mortgage is designed for borrowers who want greater certainty over their monthly payments. Instead of fixing for a shorter period (such as 2 or 5 years), you lock into a fixed interest rate for longer—often 10 years, and sometimes beyond.

This guide explains what “long-term” can mean in practice, the potential advantages and drawbacks, and the key points to compare when choosing a fixed term.

What counts as a long-term fixed-rate mortgage?

In the UK, “long-term” is commonly used to describe fixed-rate periods of 10 years or more.

You may also see longer options such as 15-year, 20-year, or 30-year fixed-rate deals. While these can provide extended payment certainty, they can be more complex to compare—particularly when you factor in early repayment charges and the overall cost of the product.

Why longer fixes may be harder to find

Mortgage product availability can change. Longer fixed terms are often offered by fewer lenders than shorter fixes, and deals may be withdrawn or altered when market conditions move.

That’s one reason it’s important to compare options based on what’s available for the exact fixed period you’re considering, rather than relying on last year’s pricing.

How a long-term fixed-rate mortgage works

With a fixed-rate mortgage, the interest rate you pay is set for the length of the fixed period. Your monthly payment will generally remain stable (subject to any changes to fees or other charges you pay separately).

At the end of the fixed term, your mortgage will typically move onto one of the following:

the lender’s standard variable rate
a new fixed rate you choose at that time
another deal type available then

What happens next depends on your circumstances and what products are available when your fixed period ends.

Benefits of fixing for longer

Long-term fixed rates can suit borrowers who prioritise stability and want to reduce uncertainty.

Common advantages include:

Payment certainty for longer: If rates rise after you take the deal, your mortgage payment won’t automatically increase during the fixed period.
More time to plan: A longer fix can help with longer-term budgeting, especially if you’re expecting life changes.
Fewer “deal decisions” to make: With a longer fixed term, you may not need to remortgage as often to secure a new rate.
Potential protection from changing lender criteria: If lenders tighten affordability criteria, it may be harder to switch later. A longer fixed term can reduce how often you need to re-apply.

Risks and trade-offs to consider

Long-term fixed-rate mortgages are not automatically better—there are trade-offs that can matter depending on your plans.

1) If rates fall, you may not benefit

Because your rate is fixed, you won’t automatically take advantage of lower interest rates during the fixed period. If the market moves in your favour, you may end up paying more than you would have on a shorter fix.

2) Early repayment charges (ERCs) can be significant

Many long-term fixed-rate mortgages come with early repayment charges. These may apply if you:

sell the property and repay the mortgage
refinance or switch deals before the fixed term ends
repay a larger-than-allowed lump sum during the fixed period

ERCs are often higher for longer fixed terms. It’s important to understand how they work for the specific product you’re considering, including what counts as an “early” repayment and whether any partial repayment allowances apply.

3) You could pay more overall

Longer fixes often carry a higher interest rate than shorter deals. Even if the monthly payment is manageable, the total cost over time may be higher—particularly if interest rates drop meaningfully after you take the mortgage.

4) Remortgaging flexibility may be reduced

If your home value increases or your circumstances change, you might want to remortgage to a better rate. With a long-term fixed rate, that flexibility can be limited by ERCs.

Is a long-term fixed-rate mortgage a good idea right now?

There isn’t a single answer that fits everyone. A long-term fixed rate can be a good match when you value certainty and want to reduce the risk of future payment increases.

It may be less suitable if you expect to:

move house within the fixed period
repay a substantial portion of the mortgage early
benefit from a likely reduction in interest rates

A useful way to think about it is to compare what you gain (stability) against what you give up (reduced flexibility and the possibility of missing out if rates fall).

How to compare long-term fixed-rate mortgages

When comparing fixed-rate deals, it’s easy to focus on the headline interest rate. For long-term fixes, you’ll usually get a more accurate picture by looking at the full set of product features.

Consider:

Fixed term length: 10 years versus 15, 20, or longer can change both pricing and risk.
Overall cost over the period you expect to keep the mortgage: The “best” deal depends on your likely timeline.
Early repayment charges (ERCs): Check how they apply if you sell, switch, or repay extra.
Fees and product charges: Some deals include arrangement fees or other costs that affect the total cost.
What happens at the end of the fixed term: Understand the likely options and how you would choose a new deal later.

Because product availability changes, it’s also sensible to compare what’s currently on offer for your chosen fixed period.

Lenders and fixed-term availability

Longer fixed-rate options are typically offered by a smaller number of lenders than shorter fixes. Availability can vary depending on factors such as:

loan size and loan-to-value (LTV)
property type
borrower circumstances
the exact fixed term length

This is why it’s often important to check the market for the specific long-term period you want, rather than assuming the same range of deals exists for every borrower.

Existing customers: what to watch for

If you already have a mortgage, your current lender may offer an “existing customer” rate. However, that doesn’t always mean it’s the most competitive option for your circumstances.

When comparing, it’s worth considering:

whether the existing customer option includes the same fixed term length you want
how ERCs compare across deals
whether switching to another product could reduce overall cost (taking charges into account)