The UK's leading price comparison, switching and advice service for energy users has urged business and domestic consumers to check their bills and meters after thousands of people were incorrectly charged by suppliers.
Energy regulator Ofgem has revealed that customers whose metric gas meters, measured in cubic meters, were read as imperials (in cubic feet) and had been charged too much. Ofgem has asked suppliers to investigate how many customers have been affected.
Julian Morgan, managing director of the Energy Advice Line, said the revelations proved how important it was for customers to always supply meter readings, to check the readings against bills and to query any anomalies.
"It could well be that the thousands of customers believed to have been affected by this error could have done nothing to prevent it," Mr Morgan said.
"But it proves that suppliers do indeed make mistakes and that customers need to be pro-active when it comes to energy.
"Faulty meters, incorrect readings and human error - unfortunately all these things do happen and can lead to significant overcharging. At the end of the day, consumers need to be vigilant."
The meter reading errors were identified by energy giant E.on earlier this year, prompting a wider prove into how many people have been over or undercharged. Ofgem has said it believes that 'a very small number' of gas customers had been affected - around 6,300 people - but that suppliers had been asked to investigate and report back.
The regulator said that customers did not need to do anything because suppliers would contact those affected. But Mr Morgan urged customers to check with suppliers themselves just to be sure.
"Given the track record of suppliers when it comes to being upfront about mistakes, we recommend that customers with a gas meter who feel they might have been overcharged to contact their suppliers and ask for their bills to be checked.
"It could well be that some affected customers have slipped through the net.
"Even with the national rollout of smart meters, which are designed to deliver real time meter readings from homes and businesses, consumers need to take care.
"Mistakes happen and technology can be faulty."
E.on has apologised and confirmed that around 350 residential and small and medium-sized enterprises (SMEs) would be refunded and compensated after the problem was discovered.
The Energy Advice Line is one of the UK's leading price comparison and switching services for business and domestic energy customers. It is also an advocate for energy market reform and has campaigned for a better deal for energy users, including calling for a ban on cold calling and changes to regulations to make it easier for all consumers to switch suppliers.
The service is completely independent and free. Consumers can quickly and simply search the market for the best available energy deals from an extensive panel of small and large energy suppliers. The service also offers a free advice line for business energy customers.
For further information visit energyadviceline.org.uk