£400 energy support vouchers going unclaimed
Many customers with prepayment meters have not yet redeemed vouchers to help with energy bills, the BBC has learned.
From 1 October, households should have begun to receive the first £400 instalment of the government's Energy Bill Support Scheme.
Post Office, the UK's biggest voucher processor, said only 60% of those eligible had redeemed the credits so far, which are valid for 90 days.
government urged consumers to use the credit as soon as possible.
It is hard to pinpoint why people have not claimed, although many people on money saving websites have complained of delays in receiving the vouchers. 
mild weather may also have played a role, with customers holding on until it gets colder to redeem them. 
Emma Bingham from West Lothian is one of those who hasn't been able to use the voucher. She said she hadn't received it yet.
"My provider said they sent the vouchers on 7 October and blamed the postal system for me not having received them yet. They said I should take it up with the postal company.
"Well, my energy contract is with my energy provider, not the postal company," adds Emma.
"I'm currently in between jobs and so I'm struggling to pay my bills and so it would have been a real help. I'm just a little bit frustrated that my energy company has taken the money from the government but not passed it through to me."
Energy Bill Support Scheme was first announced by government in May and applies across England, Scotland and Wales.  
Under the scheme, everyone's energy bill will be cut by £400. This will be applied over six months, with a reduction of £66 in October and November, and £67 every month between December and March 2023.  
For customers who have a traditional prepayment meter, which requires topping up via a key or card in a local newsagent or Post Office, the help with energy bills comes in the form of a voucher.
Post Office urged those that had forgotten to claim their October discount to bring the voucher with them when claiming November's discount.
"We encourage anyone who receives an email or letter telling them to claim their voucher at a Post Office to do so as soon as they can," wrote Post Office chief executive Nick Read.
Payment company PayPoint, which also processes the vouchers, told BBC News it has so far only redeemed half of the credit it expected to in October.
firm and fuel poverty charities are urging any prepayment customers to go through their post in case they have missed the delivery.
Its boss Steve O'Neill told BBC 5 Live's Wake Up To Money: "Obviously, there may be a number of reasons why they haven't redeemed vouchers including the mild weather. 
"What we just want to make sure is that for people who have received the vouchers that they are aware of where they can redeem it, and obviously when they need to redeem it by, to get the support they need." 
uchers, which suppliers are sending out by post, email or text, can also be redeemed with the Post Office and at PayPoint stores. 
More than four million people have a prepayment meter, and around half of those are the older, non-smart type of meter, according to the energy watchdog Ofgem.
"It's so important that everyone gets the support they're entitled to," said Gillian Cooper, head of energy policy at Citizens Advice (CA). 
CA said that by the end of September this year, it had seen more people unable to top up their prepayment meter than in the last three years combined.
Fixed monthly direct debit: Some providers will deduct £66 or £67 from each monthly bill, meaning you may pay slightly less or could adjust your payments to build up credit for the winter months. Others will refund the money back to your bank account after you've made your monthly payment. 
Monthly bills based on what you use: Some providers will knock £66 or £67 off your bill, effectively as a discount. Others are applying the £66 or £67 as credit, which will likewise reduce the total bill. 
Smart prepayment meter: Suppliers will add credit automatically to your meter. Most major suppliers told the BBC this is done in the first week of the month. 
raditional prepayment meter, topped-up at a shop: For these customers, vouchers will be sent in the post by all the main suppliers. The vouchers are redeemable at Post Office or PayPoint stores, where customers usually top up. For most suppliers, the voucher should arrive in the post by 17th of each month and is only valid for 90 days.
Ms Cooper called on customers to ensure their contact details were up to date and reach out to their suppliers if they had not heard anything on the assistance yet. 
Customers do not need to apply for the assistance, but how it is paid varies by supplier and payment method.
Research by comparison website Uswitch recently suggested that the energy crisis is pushing more people onto prepayment gas and electricity meters.
Suppliers may put customers on prepayment meters if they struggle to keep up with bills, because it helps them control how much and how often they pay for energy.
riffs on prepayment meters also tend to be more expensive, however, with Uswitch suggesting this leaves some customers more vulnerable and at risk of being disconnected.
In September, Citizens Advice also issued a warning that half a million more people could be forced onto prepayment meters due to debts to suppliers. 
"Before winter has even hit, we're seeing far too many people who can't afford to top up their prepayment meter. That means going without access to the very basics like a hot meal," Gillian Cooper at the charity added. 
"If you're in debt, your supplier has a duty to make sure you're only paying what's affordable. That includes reducing any debt repayments you're making," she advised.
A spokesperson for the Department for Business said that the "government has worked quickly to deliver the Energy Bills Support Scheme, helping a broad range of households struggling with energy bills this winter including £1,200 direct payments being made to vulnerable households."
ustomers to have their credit applied to their meter as soon as possible so that they can benefit from the scheme. 
Have you used your energy support voucher yet? Tell us about your situation by emailing haveyoursay@bbc.co.uk.
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