More than a million customers on its standard variable tariff will see their gas and electricity bills go up by £117 a year from 1 April.

The average bill will go from £1,136 to £1,254, according to Uswitch.

Prepayment meter customers will also pay an extra £106 a year.

Yesterday, E.ON said it was increasing bills for the 1.8 million customers on its standard variable tariff by £117 a year.

More suppliers are expected to announce price hikes in the coming weeks after the regulator, Ofgem, last week increased the energy price cap by £117 to £1,254 a year from 1 April.

The price cap, which came into force on 1 January, was meant to give customers on pricey standard variable tariffs a better deal.

But experts say households can save more by switching supplier.

Victoria Arrington, spokesperson at Energyhelpline, said: “The price cap still does offer some protection to consumers, but you can do so much more in order to potentially lower your bills. The best way to save money on your energy bill is to compare and switch suppliers regularly.”

She said switchers can save £300 a year on average.

She added: “Energy is the easiest big bill to switch as it takes only a few minutes and some basic information to calculate your potential savings. Consumers must vote with their feet and switch to show suppliers they expect a good deal for their custom.”

From April, EDF customers on a standard tariff will pay £286 more than the cheapest deal available today, according to Uswitch.

Rik Smith, energy expert at the comparison site, said: “Some households on standard tariffs will be hit harder than the average if their supplier prices up to the cap, which could push their bills to the edge of affordability.

“People who are already struggling with their bills are the ones who will suffer most if they are conned by the idea that the price cap represents a ‘fair’ deal.

“There are hundreds of pounds to be saved by switching to a good value fixed deal. In just a few minutes consumers can beat the price rises and avoid confusing price changes every six months.”

Top tips for switching energy supplier

If you’re looking to move provider, a good place to start is a price comparison site such as Uswitch, Energyhelpline or Comparethemarket. It’s worth getting quotes from a couple of sites to make sure you’re getting the best deal.

Alternatively, you could sign up to an auto-switching firm. These are relatively new websites that monitor the energy market for you, find you the best deal and move you across to a new supplier automatically. There are several to choose from including Flipper, Look After My Bills and Switchd. (See Which energy switching firm is best for you? for more).