Martin Lewis has warned of a hidden energy price hike that will hit tens of thousands of households in January.
Despite the government bringing in a freeze which lasts until April bills will still go up for many on the other side of Christmas.
The price cap is set to rise by 20% in January to £4,279 a year for a typical household, up from £3,549.
Massive government spending means billpayers are insulated from that increase, with the typical total held at £2,500 until April.
However, the adjustment means there will be some ‘tweaks’ to people’s bills as the underlying wholesale rates companies use to calculate how much they charge are changed.
The MoneySavingExpert.com founder says the move will be ‘trivial’ for most people but others will see a noticeable rise.
Appearing on ITV’s Goood Morning Britain, Mr Lewis said the impact will vary around the country but will be 1% on average.
People on pre-pay meters and those who choose not to set up a direct debit will notice the change more than any, paying out around an extra £100 a year.
He warned that people on those contracts ‘tend to be some of the poorest in the country’ and will bear the brunt.
Writing on his website, he said: ‘The energy price guarantee was meant to guarantee prices until the end of March (when we know the cost people pay will increase by 20%). So it will come as a surprise to many to see prices change in January.
‘For most people the change will be trivial, but it is disappointing to see more substantial increases, with some on prepay meters seeing rises of 1%, which include most of the poorest in society.’
Energy minister Grants Shapps responded to Mr Lewis’ warnings live on air, saying for most the change will be ‘marginal’ and that ‘government support is kept under review at all times’.
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