OFGEM have set down a set of rules for the way energy suppliers must report their complaints. To give a fair balance, these figures are based on complaints per 100,000 customers for each supplier
Suppliers are required to publish domestic complaints data on their websites on a quarterly basis. They must also publish their top 5 reasons for complaints and the measures they are taking to improve how they handle customer complaints.
The six largest suppliers have published quarterly domestic complaints data since 1 October 2012, and most smaller suppliers have done so from 1 April 2013.