Millions of Britons urged to submit meter readings before energy price cap rises on Wednesday

Estimated 5.3m households on standard tariffs without smart meters risk being overcharged for some of June usage

Millions of Britons could pay higher energy bills than they need to if they do not submit a meter reading before the price cap rises on Wednesday.

The estimated 5.3 million households on standard tariffs who do not have a smart meter have been urged to take action before the new unit rates for gas and electricity take effect.

The price cap, set by the regulator, Ofgem, is set to increase by 13% on Wednesday and households who do not submit up-to-date meter readings risk having some of their June usage charged at the new, more expensive rates.

The cap sets the maximum energy rates paid by homes on standard tariffs. Households who pay via direct debit will see electricity charges rise from the current rate of 24.67p a kilowatt hour to 26.11p, while gas charges will rise from 5.74p a kWh to 7.33p.

Based on the new rates, the average gas and electricity bill will increase by £221 to £1,862 a year. The step up reflects the spike in global energy market prices caused by the war on Iran.

Ben Gallizzi, an energy expert at the price comparison website Uswitch, said “Customers who don’t have a smart meter should submit their readings before or on Wednesday 1 July, so their supplier has an accurate view of their account.”

He said people on standard tariffs should also look for a cheaper deal.

Although the price cap is going up, “your bills don’t have to,” Gallizzi said. “There are currently 27 fixed deals available that are cheaper than July’s price cap.”

For those looking to fix their unit prices, at the time of writing, Uswitch’s best buy table was topped by Outfox Energy at £1,577 a year for the average household, 15% below the July price cap.

The good news, of sorts, is that the higher rate is kicking in during warmer, brighter months when households are not using their heating.

Another bill rise had been predicted when the cap resets again in October, but that looks less certain after the recent interim peace agreement signed by the US and Iran led to declines in wholesale gas prices .