Npower will raise standard tariff electricity prices by 15% from 16 March 2017, and gas prices by 4.8% meaning a typical dual fuel annual bill will rise by over £100 a year.
The price rise comes after three other suppliers – British Gas, Eon and SSE said they would wait until end of March 2017 before making a decision on prices.
In response to customer questions Npower states on their website
“This is the first time our energy prices have gone up since 2013. But over the past few years, the cost of supplying energy to your home has increased, as well as the amount we need to pay towards government schemes, such as fitting Smart meters,”
1.4 million Npower customers on existing standard tariffs are to be offered a four-year fixed-price tariff with a 4.8% discount, while prepayment customers will not be affected by the increase.
Around 80,000 people who receive a warm home discount will in effect pay no increase until May 2017.