Martin Lewis has issued a warning to all UK householders over changes to their gas and electricity bills due to be announced this week (February 5).
Higher wholesale costs mean households are likely to pay more for their energy in 2021, when compared to the past 12 months.
Speaking on The Martin Lewis Money Show, on ITV, Lewis revealed the energy price cap is set to go up later this year.
As a result, the big energy firms will likely start raising their bills - by up to £90 a year.
Energy regulator Ofgem sets the limit in a bid to cut the price a supplier can charge per unit of electricity and gas.
The new cap will start on April 1 and last for six months, and will apply to everyone on a standard tariff paying by direct debit.
But Money Saving Expert Lewis said: "They call it a price cap, in reality it isn't a price cap - it's a rate cap. There's no one price you shouldn't be paying more than.
"The current rate for someone on typical use in £1,042 a year, and most of the big firms follow it within an pound or two.
"And here's the prediction - it's due to rise between £70 and £90."
But Lewis added that until firms launch their new rates - in accordance with the new cap on April 1 - annual savings will be based on the current cap.
So it's a good idea to take a look at the market, and secure a good deal on gas and electricity bills now.
According to Lewis, this also applies for prepay and electric only.
He highlighted a number of suppliers currently offering deals that could save consumers up to £100 a year.
The default tariff price cap is expected to increase from £1,042 - it's current level - to over £1,100 on a typical dual fuel direct debit account.
