Savers have been warned not to be blinded by loyalty, as it could cost them hundreds of pounds.
Rates scrutineer Moneyfacts said those who let their nest egg languish in old accounts could be losing out on hundreds of pounds per year, as banks reduce the interest rates and hope customers won't notice.
An average closed easy-access savings account, meaning one that is no longer available to new customers, pays only 2.39 per cent, which is below the rate of inflation.
Inflation is currently sitting at 2.8 per cent, so any account paying less than that in interest will see your money lose value in real terms.
Someone with £20,000 in savings would lose £322 a year, compared to an account paying 4 per cent, Moneyfacts said.
Watch out: The report by Moneyfacts urged savers not to be blinded by loyalty as it could cost them hundreds of pounds
Even among accounts that are still live, four in five easy access savings accounts pay less than 3.75 per cent, the current Bank of England interest rate.
The best savings rates are usually around the level of the base rate or above.
The average savings rate is now around 3.57 per cent, its highest point since May 2025, although some accounts pay far better rates.
You can use This is Money's best-buy savings rate tables to find the best account for you across easy-access, Isas and fixed-rate deals.
Topping the table is the Cahoot Sunny Day Saver, which pays 5 per cent interest. The catch is that customers can only pay in up to £3,000 per year, so those with larger savings pots would need to split their money up.
They can get the rate for up to 12 months, although it is variable so Cahoot can change it at any time.
The Tembo Home Saver pays 4.55 per cent on balances up to £25,000. However, this includes a 'bonus rate' of 1.55 per cent, meaning the rate will drop to 3 per cent after a year. It's designed for people saving for a home, but this isn't a requirement.
Elsewhere, Hampshire Trust Bank's easy access account pays 4.24 per cent with no bonus or restrictions.
Those looking to protect their savings from tax may also want to consider an Isa. This is the last year to use up the full £20,000 cash Isa allowance before it is reduced to £12,000 in April 2027, apart from for over-65s.
You can get a 4.51 per cent rate from Trading 212 on a cash Isa, though this will drop to 3.60 per cent after a year.
You can also get a 4.4 per cent rate from the Moneybox Cash Isa on balances of £500-plus, dropping to 3.45 per cent after 12 months.
Some eight million British workers don't have any emergency savings, it was revealed this week.
Rachel Springall, finance expert at Moneyfactscompare.co.uk, said: 'Savers blinded by loyalty or failing to check their easy access accounts regularly could be earning a paltry rate.
'Even if savers have a small amount saved, a pot out of sight means it is out of mind. Convenience comes at a cost, so savers who keep their pots with a high street bank, or even in a current account, are not making their money work as hard as it could.
'You can’t blame savers for feeling apathetic, but it’s important to review rates every six months or so at the bare minimum.
'Savers can automate the habit by using apps which are designed to move disposable cash out of a bank account, which can be a satisfying way to grow a savings pot gradually. However, those with lump sums could be better off opening a fixed rate bond or Isa, to lock into a guaranteed rate for peace of mind.'
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