The energy giant pledged not to raise prices in 2012, but is raising them only 18 days into 2013.

From the 18th January, E.ON’s household tariffs will be increased by 8.7% on both electricity and gas, it was announced.

The German-owned energy supplier made a ‘price promise’ to not raise prices in 2012, but is raising them only weeks after all of the other suppliers imposed similar price hikes.

This winter we have already reported on price increases of between 6% and 10.8% by Scottish & Southern, British Gas, Npower, EDF Energy and ScottishPower The table below summarised the price chances they are making.

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We can expect (as in recent years) all of the suppliers to make token reductions in the new year. See our summary of the annual ‘energy price shuffle’ from last winter here.

We’ll be reporting on any price reductions in the new year, so make sure you follow us on Twitter or Facebook, and sign up to Utilities Insider – our bimonthly energy newsletter.