Will Morris, SSE retail managing director, said the firm was "sorry" to have to raise its prices:
We're sorry we have to do this.
We've done as much as we could to keep prices down, but the reality is that buying wholesale energy in global markets, delivering it to customers' homes, and government-imposed levies collected through bills - endorsed by all the major parties - all cost more than they did last year. Eighty five per cent of a typical energy bill is made up of costs outside our direct control and these costs have increased.
So far this year we have made a loss from supplying energy as a result of the higher costs we have been facing and continue to face. We understand and regret that this will add to the pressures on household budgets, but there's a lot we can do to help.
Rising unit prices do not have to mean rising bills and there remains huge potential for customers to save money by improving further their energy efficiency.
After SSE announces gas and electricity tariffs will prices will rise next month, other big energy firms refuse to rule out own price hikes.
Some tips on how to save money on your energy bills.