Ofgem is concerned that some customers may have been overcharged when their bill covers a period before and after the introduction of a higher tariff. The regulator is worried that firms may sometimes have applied their increased charges to too much of a customer's gas or electricity usage. News of the enquiry comes on the day that British Gas puts up its prices. Its average gas tariff is rising by 18% and its electricity prices by 16%. As a result its dual-fuel customers will be charged about £190 more a year.

Ensuring accuracy
The problem of bills being calculated on consumption before and after a tariff increase was highlighted earlier this week. One of the big-six energy suppliers, EDF, admitted it had overcharged 100,000 customers between October 2003 and May 2010. When they had rung in with correct meter readings after receiving estimated bills, EDF's automated system had charged all .....Read more on this story HERE