A postcode lottery in energy prices means that consumers in some parts of the UK pay almost 30 per cent more than those in others, research showed today.

People in Yorkshire and Humberside pay 28 per cent more for gas and electricity than consumers in the south-east of England, according to price comparison website Fairinvestment.co.uk.

The discrepancies can lead to some consumers paying £300 extra a year.

The average monthly spend on energy bills is as high as £1,416 per couple in Yorkshire and Humberside, but as low as £1,104 in the south-east.

John Corboy of Fairinvestment said: “It seems unfair that the same product should cost more or less depending on your postcode, especially when prices are already shooting up."

“It is surprising that the regional difference in gas and electricity prices is as high as 28 per cent, despite the fact that most energy companies use regional pricing methods,” he added.

The research also found that the average couple pays £1,248 on energy per year. The average national monthly spend on gas and electricity is £52 per person per month, or £104 per couple.

In the past year, energy prices have gone up 40 per cent, according to price comparison site Confused.com.

However, there are ways you can save money. Up to 13m households, or about half of all energy customers, have never switched suppliers and could save an average £200 – and in some cases as much as £500.

The energy giants penalise loyal customers who pay by cheque or cash, have separate suppliers for gas and energy and do not manage their accounts online, so you can make big savings by switching to dual fuel, taking out an online tariff and signing up to pay by direct debit.

There are also simple cost-saving measures you can take to reduce household energy consumption:

* A three-bedroom detached home could save £40 a year by switching to energy-saving light bulbs, according to the Energy Saving Trust.

* Turning the thermostat on your central heating down by one degree would save £70 a year.

* Turning an appliance off instead of leaving it on standby would save another £30.

* Washing your laundry at 30 degrees, instead of 40, could cut costs by £10 per year.

* Only boiling as much water as you need could take another £10 per year off energy costs.

* Turning off the lights could cut costs by about £10.