If you're thinking of switching energy provider, be aware that energy prices haven't dropped this year – even though firms are now listing lower annual costs on websites.

Gas and electricity suppliers publish the average annual, or monthly, cost of tariffs on their websites to indicate how much bills cost a typical household (join our free Cheap Energy Club to find the best deal for you).

At the start of this month, these advertised costs seemingly fell. That was because energy regulator Ofgem changed its guidelines on how much energy a typical home uses in a year.

Homes now use less energy, so annual prices have dropped compared with last year.

Comparison sites and switching services, including MoneySavingExpert.com's Cheap Energy Club, also use these average consumption figures if you ask for prices to be guestimated based on typical usage.

  • Ofgem's new guidelines – which it reviews every two years – say a typical household on a single rate meter consuming a 'medium' amount of energy uses 13,500kWh of gas and 3,200kWh of electricity over a year. Last year, these figures were 16,500kWh of gas and 3,300kWh of electricity.

  • Meanwhile a typical household consuming a 'low' amount of energy now uses 9,000kWh of gas and 2,000kWh of electricity over a year, compared to 11,000kWh of gas and 2,100kWh of electricity last year.

  • And a typical household consuming a 'high' amount of energy now uses 19,000kWh of gas and 4,900kWh of electricity over a year, compared to 23,000kWh of gas and 5,100kWh of electricity last year.

One of our top picks – EDF's Blue+ Price Freeeeze, which is fixed until 31 March 2017, for example, is now listed at £1,202/year for a typical dual fuel user using a medium amount of energy, compared to £1,340/year before 1 January.

Despite the change to the way these figures are presented, bills haven't dropped in real terms – in fact, they've risen.

All the big six suppliers – Scottish and Southern Energy, British Gas, Npower, Scottish Power, EDF and E.on – have hiked prices by 4%-10% on average this winter (see our Cheap Gas and Electricity guide for more information).

If you haven't already checked if you can save by switching energy tariff, you should do it now. Join our free Cheap Energy Club to find the best deal for you. It'll also monitor your tariff to ensure it's always your cheapest, and tell you when to switch again.