UK households have just days left to act, or risk finding themselves £400 out of pocket.

Millions of homes across England, Scotland and Wales, received an automatic £400 discount on their energy bills through the Energy Bill Support Scheme (EBSS) over winter.

However, customers who pay for their energy through traditional prepayment meters were sent vouchers instead.

These vouchers can be taken to their local top-up points and redeemed in order to save money on their bills.

But at the start of the month, thousands of households had still not redeemed their vouchers, with more than £130 million worth of vouchers going unclaimed.

Vouchers must be used by June 30.

Which? warned: “Make sure you claim your Energy Bill Support Scheme (EBSS) vouchers soon! If you haven’t redeemed any vouchers so far, you’ll be out of pocket by £400.

“All vouchers must be used by June 30.

“If you haven’t redeemed an expired EBSS vouchers, or didn’t receive it, ask your energy supplier to re-issue it.”

Which? energy editor, Emily Seymour said: "Any lost, missing or expired vouchers can be reissued, as long as they are redeemed by June 30, 2023.

Daily Echo: Vouchers worth up to £400 as part of the Energy Bill Support Scheme must be redeemed by June 30 Vouchers worth up to £400 as part of the Energy Bill Support Scheme must be redeemed by June 30 (Image: Rui Vieira/PA Wire)

"If you are on a traditional prepayment meter and haven’t received your vouchers, are unsure of how to redeem them, or need a voucher to be reissued, you should get in touch with your supplier for more information."

The Government are also pushing for anyone with unclaimed vouchers to act before the June 30 deadline.

Amanda Solloway, minister for energy consumers and affordability, said: “We are redoubling our efforts to reach anyone who still hasn’t claimed this help, and it's fantastic to see so many join our final push to spread the word.

"Tell friends and family or anyone on a traditional prepayment meter to use their vouchers for up to £400 off bills before June 30 – there is still £130 million out there to claim."