The Government has called on Good Energy, Utilita and Scottish Power to help their prepayment customers claim £400 in support vouchers after naming them as falling short on sending the help out.

Around 30% of vouchers have not yet been redeemed by prepayment customers, despite freezing temperatures in recent weeks, Government figures published on Monday show.

E Gas and Electricity is among the best at delivering the Energy Bills Support Scheme (EBSS) with an 85% redemption rate, while Bulb is second on 79%.

Those with the fewest redemptions include Good Energy, Utilita and Scottish Power, with the Government calling on them and others to make sure they are doing all they can to ensure customers with prepayment meters know what to look for and how to redeem the vouchers.

Some £5.7 billion has been provided to 99% of households in Great Britain through the scheme, with 71% of prepayment vouchers redeemed so far, according to the figures.

Customers receive the discount in the same way they pay their energy bills, such as by direct debit, credit, smart meters and prepayment meters.

Most people receive the support automatically, but those on prepayment meters are sent monthly vouchers by their supplier by text, email or post.

Suppliers are expected to tell customers where to redeem vouchers – at a Post Office branch or a PayPoint shop – and must make several attempts to contact customers who have not redeemed their vouchers.

Business and Energy Secretary Grant Shapps said: “The public have a right to know which suppliers are leading the charge with getting this help to them, and that’s why I’m holding energy companies to account to make sure they are doing everything they can to support their customers at this time.

“We’re ramping up efforts so consumers know exactly what they need to do to redeem these vouchers, but we need suppliers to do much more and I want to see these numbers rise.”

Which? director of policy and advocacy Rocio Concha said: “It is very concerning that around 30% of vouchers still haven’t been redeemed – even with freezing temperatures last month – and that suppliers including EDF, Scottish Power, Energy Plus Supply Limited, Good Energy and Utilita are falling short in making sure this support reaches their customers.

“As an urgent priority, the Government and energy suppliers must work together to share best practice and quickly improve the scheme to ensure that all customers on these prepayment meters – who are more likely to be vulnerable and on lower incomes – are able to access this vital support without further delay.

“Traditional prepayment meter customers should also be prioritised in smart meter rollouts where appropriate, so that financial support can be delivered automatically in future.

“If you are on a traditional prepayment meter and haven’t received your vouchers or are unsure of how to redeem them, you should get in touch with your supplier for more information and to make sure they have the correct contact details.”

Good Energy chief executive Nigel Pocklington said: “As a supplier with a relatively tiny proportion of prepayment customers, we have been able to go above and beyond in encouraging EBSS voucher redemption.

“We do not install traditional prepayment meters because they are not effective for supporting customers.

“For the around 350 legacy traditional prepayment customers we do have, we have sent multiple email and letter reminders as well as made individual calls.

“Our own up to date figures show our customers’ redemption rates are around 70% — in line with the Government’s average.

“We will continue doing everything we can to make sure customers don’t miss out on this vital support.

“We would like to see the Government doing the same, rather than lashing out at suppliers for the shortcomings of their own scheme.”

A Scottish Power spokeswoman said: “Our investigation of unclaimed credits identified vacant properties as one of the main reasons for money going unclaimed and we are updating our system to reflect these accounts. When this is factored into our reporting our redemption rate is 74%.”

Utilita said: “We have a small number of customers with traditional pay as you go (PAYG) meters. Some have yet to redeem their EBSS vouchers – we estimate the figure is less than 2% of the national total – despite our best endeavours.

“The real problem here is one of old-fashioned traditional PAYG compared to Smart PAYG+ of which we have 665,000 households – 95% of our PAYG customers – with 1.3 million smart gas electricity meters. Here, we have successfully applied EBSS payments directly on to the meter on more than 2.6 million occasions, with 99.999% success.”

Energy UK chief executive Emma Pinchbeck said: “Customers with traditional prepayment meters are advised to ensure their contact details are up to date and to check regularly for any communication from their supplier.

“Anyone worried about missing their vouchers or struggling to pay their bills should get in touch with their energy supplier.

“The Government knows from the billions of pounds of benefits that go unclaimed every year that it can unfortunately be hard to get assistance to those who need it most, but we remain fully committed to ensuring vouchers are delivered and redeemed and to make the support schemes work as successfully as possible.”

The figures follow Mr Shapps’ demand over the weekend that energy suppliers stop forcing financially stretched households to switch to prepayment meters.

He also vowed to “name and shame” the worst offenders.