The energy cap limits the maximum price that can be charged for each unit of gas and electricity, rather than the total bill.
This means people in larger properties will tend to pay more overall owing to higher energy usage, and those in smaller properties tend to pay less.
The energy watchdog Ofgem’s price cap, external affects 29 million households in England, Wales and Scotland. Different rules apply in Northern Ireland.
Dr Craig Lowrey, principal consultant at Cornwall Insight, said that while bills will remain “largely unchanged” from October, the news that prices will not drop after rises were seen in the Autumn will still be “disappointing” for many.
“What we’ve been looking at were prices well above the historic norms,” he told the ‘s Today programme.
He added that there “doesn’t seem to be any sign of a return to pre-energy crisis levels,” referring to the spike in costs seen when conflict between Russia and Ukraine broke out.