Ministers have urged households using prepayment meters to redeem vouchers offering support for their energy bills, as the government said £160m remained unclaimed.
Households with traditional analogue prepayment meters are entitled to claim discounts of up to £400 on their energy costs under the energy bills support scheme, which is open until 30 June.
But new figures show more than a fifth of the vouchers, 2.4 million, remain unclaimed. The government said £780m in vouchers had been sent to consumers, with £620m claimed.
The vouchers were sent by post or email and need to be taken to a post office or PayPoint vendor to be credited to the meter. For households on direct debit and those with a smart prepay meter, the payments were automatically passed to consumers by their energy supplier.
Research showed that for the fifth month in a row, London had the lowest redemption rate, with a third of vouchers still unused at the end of February. About 26% of vouchers in Scotland and the south-east of England are also yet to be used.
The voucher scheme is part of a wider government effort to bring down the cost of gas and electricity for consumers because of the energy crisis fuelled by the war in Ukraine.
After months of warnings from campaigners and business leaders, the government intervened last autumn to cut household energy bills. Last month, the chancellor, Jeremy Hunt, U-turned on a plan to make its subsidy scheme less generous.
Data has shown consistently that between a fifth and a quarter of the prepay vouchers have remained unredeemed since the scheme’s launch.
Amanda Solloway, the minister for energy consumers and affordability, said: “Even as the warmer weather sets in I urge anyone on a traditional prepayment meter to act now if they haven’t redeemed their voucher.”
Nick Read, the chief executive of the Post Office, said: “Claiming your voucher at a post office is really simple: just bring your voucher, your energy prepayment key or card and the ID specified in your voucher letter and we will redeem the voucher for you at the counter.”
Read said the vouchers were valid for three months but those with expired documents should contact their electricity supplier and ask for replacements.
The figures come amid wider concerns over households on prepayment meters after Citizens Advice said 3.2 million people were left with cold and dark homes last year after running out of prepay credit.
The Guardian revealed last week that energy firms have agreed not to forcibly fit the meters in the homes of people over 85 or with certain medical conditions when an industry-wide ban is lifted, after evidence that companies were ignoring customers’ vulnerabilities.
Separately, the government said consumers without a domestic electricity supply – such as residents of caravan parks – can apply for £400 in support until the end of May. Those using alternative fuels, such as heating oil, have until 31 May to apply for £200 of support.
