SSE last increased electricity prices in August 2008 and gas prices in December 2010.
The changes will affect around 5.2 million household electricity customers and around 3.6 million household gas customers in Great Britain.
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The firm told customers there were three reasons why they put up prices.
"First, the cost of using the energy networks to distribute electricity and gas to customers' homes, which is determined by Ofgem, is 14% higher than it was a year ago.
"Second, the cost of the mandatory environmental and social schemes that suppliers are required to fund, like the Carbon Emissions Reduction Target (CERT) and the Warm Home Discount, is 11% higher than it was a year ago.
"Third, the wholesale cost of electricity and gas has gone up by around 23% and around 40% respectively since SSE last announced a price increase for household gas," a spokesperson said.
(GK)
