There's more good news on the way for customers of big energy firms British Gas, Eon, EDF, Ovo, Octopus and more this year as Martin Lewis has given a date customers can expect an even bigger boost to their finances.

As you probably know, the Ofgem energy price cap is changing on Monday, April 1, meaning big firms also including the likes of Shell and Scottish Power will be handing out cash boosts to customers somewhere in the region of £238 to £288 depending on the tariff and the offer from each company, largely powered by a drop in the UK price cap.

Now money saving expert Martin Lewis, who founded MSE Money Saving Expert, says there's another boost set to come later this year from gas and electricity companies which will take the total boost to £440.

Read More: Eon issues message to customers with £288 boost from April

Martin told his BBC Radio 5 Live listeners that on July 1, the price cap from Ofgem is changing again and although the precise amount is not yet confirmed, current predictions from analysts Cornwall Insight have pegged the reduction at about 13% from July 1.

That's in addition to 12% already coming off average bills from Monday, April 1. It means that the total saving will be in the region of £440, but it could be even more once the tariffs are set by the likes of Octopus and E.On, both of which have promised to price below the price cap.

Martin said: "After the 1st of April, they'll go down to around £1,690 because the price cap is dropping 12%, that's locked in.

"The prediction is, on the 1st of July, rates will drop 13% from the April price cap.

"So that's another 13% on drop. Now that will take our person who started on £1,930 down to £1,490."

That's a tidy £440 boost thanks to a cut in the underlying gas and electricity unit rates for an average household's usage. But will it definitely happen?

Martin added: "So the next question is, how certain are we of that prediction?

"Well the July price cap is based on prices from mid-February to mid-May. And we're currently towards the end of March so we're not halfway through but we're close to halfway through.

"So for that to be hideously out of kilter we will need a seismic change in wholesale rates over the next six weeks or so."