Some energy adverts promising large discounts and free energy are leaving consumers duped at best but often out of pocket, according to an investigation.
Which? found that one ad for Southern Electric (SSE) claiming to make customers up to £100 richer could have ended up actually costing people £133. Another ad for E.ON offering two months' worth of free energy saved people just £4.
The watchdog monitored and analysed energy company ads for more than a year, concluding that seven of them could be misleading. While it found that most of the claims made in the seven ads were "strictly speaking" correct, they could be making the deals and offers sound more tempting than they actually are.
The SSE ad promised that consumers would be up to £100 richer if they switched to its capped tariff. A survey by Which? found 80% of people agreed that this implied they would be £100 better off and 53% believed this appeared to be a good deal.
But Which? said: "This is a capped tariff. Prices can't go up for two years but can go down. Assuming prices don't change, an average user would pay £233 more a year than the cheapest deal. Even with £100 off, they'd be £133 poorer."
The British Gas Fix and Fall tariff, widely advertised when the company announced price rises earlier this year, promises that people will benefit from any fall in prices, despite fixing their deal.
Which? warned: "The ad came out the day after British Gas revealed 6% price rises. The tariff was £1,309 a year for dual fuel. SSE's two-year Capped Price Plan 2 was £35 cheaper. The cheapest fixed tariff for a similar period (up to March 2014) was £222 cheaper. In addition, for it to be a good deal and better than the cheapest fixed tariff, prices must fall at least 17% by March 2014 - not very likely. You'll be £100 richer ... sorry, that's £100 poorer."
Customers taking up a promise in an E.ON ad of two months of free energy were automatically excluded from the normal discounts of 8% for taking dual fuel and paying by direct debit, leaving an actual saving of just 0.33% or a £3.80 saving on the average annual bill. E.ON said: "We're sorry this ad was confusing. Following feedback we withdrew this tariff and now have a far clearer, simpler range with no more than five tariffs to choose from."
SSE told the consumer group: "SSE has fair prices and simple products. Our capped tariff ensures prices won't go up for two years and customers get £100 credit. We will take your findings on board."
British Gas said: "We disagree with Which?. We received no complaints relating to your allegations. We test our ads with customers so they deliver our messages as clearly as possible."