Millions of customers are missing out on huge energy bill savings each year by failing to take simple steps to save money, a watchdog and energy industry body say.
As part of Big Energy Week, Consumer Focus and Energy UK are urging customers to reduce their bill by better insulating their homes and checking that they are on the best tariff or payment method.
New Government figures show that 9.6 million homes do not have adequate loft insulation, and 7.8 million do not have enough cavity wall insulation - which amounts to one in four homes.
Many energy suppliers offer free or discounted loft and cavity wall insulation, which can save consumers an average of £120 on their bill every year. Switching their payment plan to direct debit can save people around a further £100 each year.
Despite free or cut-price deals for insulation being offered, not enough people are taking advantage. Currently just 100,000 households are taking up these deals each month when 200,000 homes could be taking advantage of them.
Mike O'Connor, chief executive of Consumer Focus, said: "Millions of consumers are finding it hard to afford higher energy bills and every penny that can be saved counts.
"Yet many people are paying more than they need to because their home is leaking heat and they aren't on the cheapest deal. Yet with one simple call to their energy firm many customers could make big savings on their bill.
"Changing to a cheaper tariff or payment type can cut your costs. Many people also don't realise that energy companies offer free or discounted insulation - and it's a waste not to take advantage of these offers which could shave well over £100 off your bill every year."
© 2012 Press Association