Fixed-price deals are not affected by the energy price cap, which changes every three months and can go up or down.

They offer certainty for a set period – often a year, or longer – but if energy prices drop when you are on the deal, you could be stuck at a higher price. You may also have to pay a penalty to leave a fixed deal early.

Ofgem, the energy regulator, says customers who want the security of knowing what their bill will be should consider moving to a fixed deal before April. However, it says they should make sure they understand all the costs.

Martin Lewis, founder of Money Saving Expert, told the BBC that the level of fixed deals currently on offer means that switching is a “no-brainer”.

He recommends checking whole-of-market energy price comparison sites to help find the best deal. They should also consider waiting a little while as some “good tariffs are being launched”, Mr Lewis said.

However, analysts at consultancy Cornwall Insight who monitor the energy market have predicted that the cap could fall back again in July, to close to the current level.

Ofgem says around four million customers have moved to a fixed tariff since the last price cap announcement, in November 2024.