Information on the number of households assisted by energy suppliers with social and discounted tariffs is available in the reports published by Ofgem on suppliers' social spending. These reports are available via the following link.
The definition of a social tariff changed during 2007-08 and 2010-11. Therefore the following figures reference the number of households assisted with both social and discounted tariffs, in line with Ofgem's method of reporting. The information published by Ofgem shows that in 2007-08 around 800,000 customer accounts were benefiting from social and discounted tariffs and from 2008-09 to 2010-11 around 1 million customer accounts benefited each year from social and discounted tariffs.
Under the new Warm Home Discount scheme which began in 2011-12 energy suppliers are required to report on their spending under the Warm Home Discount scheme to Ofgem at the end each scheme year. Once this information has been verified and audited, Ofgem will produce a report which will detail the number of customers assisted with social and discounted tariffs under the legacy spending element of the Warm Home Discount scheme.