Savers can lock their money away for anything from a few months to five years, but choosing the longest term does not necessarily produce a meaningfully better return.

Afin Bank’s leading five-year bond currently pays 4.96 per cent, compared with 4.91 per cent from the top one-year account at OakNorth Bank.

On £10,000 saved, that difference is worth just £5 gross in the first year in earned interest.

In exchange for that modest advantage, savers must give up access to their money for an extra four years. So how long can you genuinely afford to lock your cash away?

Why does five years pay so little more?

Rachel Springall, finance expert at Moneyfactscompare.co.uk, explained: “In a traditional savings market, providers would offer much higher longer-term fixed rates than their short-term counterparts, as a reward for fixing for longer.

“However, due to recent years of short-term unrest it has led to one-year fixed bonds paying some of the highest rates and very little margin against these versus the top five-year fixed options - it can be difficult for providers to price their longer-term deals in uncertain times.”

The Bank of England’s base rate has remained at 3.75 per cent since December, yet fixed savings rates have risen during 2026.

Anna Bowes, personal finance expert at The Private Office, noted: “The top 1-year bond is currently 4.91 per cent, compared with 4.45 per cent at the start of the year.”

Start with when you will need the money

Money needed for emergencies or known spending should remain accessible. Cash that may be required within two years won’t belong in a five-year bond, even if it pays slightly more.

“It’s important to know that in the majority of cases, once you have deposited funds into a fixed term bond, there is no access allowed until maturity,” Bowes says.

Choosing a one-year fix leaves savers free to reassess next summer. They could then move the money into another one or two-year account, potentially spreading interest across different tax years.

However, this depends on the rates available when the bond matures. The Bank of England’s June survey of market participants showed a median expectation that Bank Rate would remain at 3.75 per cent into early 2027, before falling to 3.25 per cent by the end of that year.

Could a savings ladder offer a compromise?

Savers who want some protection against falling rates without locking away their entire pot can divide it between bonds with different maturity dates.

Someone with £10,000 for example could put £2,000 into each of a one, two, three, four and five-year bond. One portion would then mature every year.

Bowes says: “By the end of the fifth year, all your cash could be earning five-year interest rates, but a fifth of it will be maturing each year, should you need it.”

Most of the money would still be inaccessible at any one time, while future rates are unknown.

Don’t overlook the tax bill

Basic-rate taxpayers can normally earn £1,000 of savings interest tax-free each year, while higher-rate taxpayers receive a £500 allowance and additional-rate taxpayers receive none.

At 4.96 per cent, £10,000 would generate £496 in a year, almost using a higher-rate taxpayer’s full allowance. A lower-paying cash ISA could therefore leave them better off after tax.

Savers should also check when interest becomes taxable. If it cannot be accessed until maturity, several years of returns may fall into one tax year, generating a tax bill to be paid.

Where annual interest can be accessed, it may instead be taxable each year, depending on the account terms.

When should cash become an investment?

Anyone considering a five-year bond should also ask whether all the money needs to remain in cash.

Cash offers certainty, making it suitable for emergencies, planned spending and people unwilling to accept potential investment losses.

Someone with no plans to use the money for at least five years may have time to consider investing part of it, as over the long term, investing tends to produce better returns than saving cash alone.

The Financial Conduct Authority says investing over at least five years gives money more opportunity to recover from short-term market falls, though returns are never guaranteed.

Cash also faces inflation risk. Consumer Prices Index inflation stood at 2.6 per cent in June, meaning today’s leading bonds currently provide a return above inflation before tax. Nobody knows whether that will remain the case throughout a five-year term, but inflation is expected to rise across the rest of 2026 at least.

So how long should you fix for?

For many savers, five years will be too long to surrender access when one-year accounts pay almost as much. A shorter fix may suit those whose plans could change, while a savings ladder avoids having an entire pot inaccessible at once.

A five-year bond is easier to justify when the money will definitely not be needed, preserving the capital matters more than pursuing investment growth and the saver wants protection against future rate cuts.

The right term is the longest period a saver can comfortably commit to, rather than the longest bond available.

An extra £5 on £10,000 is unlikely to compensate for four additional years without access unless the certainty of today’s rate is the real prize, even after tax.

When investing, your capital is at risk and you may get back less than invested. Past performance doesn’t guarantee future results.