Money Saving Expert founder Martin Lewis has warned customers who pay their energy bills via direct debit about steps they can take to mitigate the rise in costs.
From October 1 people who pay their bills via direct debit will be charged up to 10p per kilowatt hour of gas that they use and 34p per kilowatt hour of electricity.
This is a rise of 3p for gas and 6p for electricity from the previous totals of 7p and 28p for electricity, the Liverpool ECHO reports.
Mr Lewis put the warning out on social media that people can mitigate their costs by submitting a meter reading to ensure that they are not charged on the new tariff for usage they did before the new tariffs.
The founder of Money Saving Expert issued the message on his twitter page, writing: "WARNING: It's #MeterReadingWeek. On Sat most energy bills rise 27%".
He also posted a clip that clarifies what customers should do as the price rise comes into effect.
In the video, Mr Lewis said: "If you pay by direct debit, firms estimate your use and they also estimate when it's used, so you don't want them to assign more of your units to the more expensive period.
"How do you stop that? You submit a meter reading. Take a picture, too, so you have evidence.
"That way, there's no estimate and there's no discrepancy.
"Those with working smart or pre-pay meters, you don't need to bother, but you [still] might want to take a picture of where you're at on the day."
However, Mr Lewis also shared a tip that could benefit some on pre-pay meters.
"If you've got cash now, and I know many people don't have cash, but if you do... topping up in September, you could then keep that rate into October and beyond, when the prices rise".
He said you'll keep that rate until you top up again, though it doesn't work with gas, or if you're on a smart meter.
Mr Lewis added: "If you're on a pre-pay meter with E.ON or Scottish Power they have told me it won't work. But all the rest of the big firms, they've said it is likely".
