Energy regulator Ofgem has written to all energy companies asking them to check whether they have correctly billed gas customers, after an error at a big six company has come to light.
Providers have to report back to the regulator by the end of this week.
The move comes after E.on revealed it has wrongly billed some gas customers.
- Use our Energy comparison tool to see if you can switch and save.
While all new domestic gas meters – metric meters – measure gas in cubic meters, some older imperial meters are still in use, which measure energy in cubic feet.
E.on says some of its gas customers with a metric meter have been registered as having an imperial meter and vice versa. It says this means about 350 current users have been overcharged, while about 250 current customers have been undercharged.
It will contact affected customers to arrange a refund where they’ve overpaid, although it won’t ask for money back where users have underpaid.
E.on is also undertaking “urgent work” to establish whether any former customers have been affected. It says these customers will be treated in the same way as current customers, and adds that attempts to contact any affected former customers will be made as soon as the work is completed.
Ofgem says its letter to providers advises energy companies to refund customers where households have overpaid, but not to collect any underpayments.
It expects the issue will only affect a very small number of customers. It says E.on’s error only affects 0.03% of its customers.
A spokesperson for Ofgem says: "Ofgem is working with suppliers to ensure consumers don’t lose out. This includes suppliers setting out plans to redress their affected customers, and to reach a quick resolution.
“Customers do not need to do anything. The very few affected will be contacted by their supplier.”
Ensure your bills are correct
Ensure you submit regular meter readings so that your provider can correctly bill you for your energy, rather than making estimations.
With a metric meter, the part units of gas are highlighted in red and those digits are often separated by a decimal point. With an imperial meter, the part units are often displayed in the form of a dial.
See gov.uk for more information on this.