SSE and Innogy SE - the owners of Npower - have confirmed they've reached an agreement to merge their energy supply businesses.
The merger would see two of the big six energy suppliers come together to create a new independent energy company.
The two suppliers say they hope to complete the merger and establish the new combined supplier by the end of 2018 or beginning of 2019.
If you're with either supplier, there's no need to panic - the deal stills needs competition and regulatory agreement. Plus if it does go ahead, there'll be no interruption to your energy supply. Yet if you're a typical user on a standard tariff with SSE or Npower, switching supplier now could save you between £280/yr and £335/yr.
Get Our Free Money Tips Email!
What would the new supplier look like?
It would be a completely new supplier, independent of either SSE and Npower, though it would combine both suppliers' household gas and electricity supply businesses, and Npower's commercial supply business.
SSE currently has a 11% share of the UK domestic gas supply market, ahead of Npower with 8%, according to Ofgem. For electricity, SSE has a 14% share and Npower 10%.
In comparison, Britain's largest supplier - British Gas - has a 33% share of the gas market and 22% share of electricity.
The combined SSE and Npower company would easily be the second-largest supplier in Britain - providing energy to around 11.5 million customers - and would even overtake British Gas for electricity supply.
When is it likely to happen?
Though the merger has been agreed and accepted by both suppliers, it still needs competition and regulatory approval before going ahead. It also needs the approval of SSE's shareholders and Innogy's supervisory board.
However, both firms currently expect the merger and the creation of the new company to happen by the final quarter of 2018 or in early 2019.
'Competitive landscape and uncertain political environment'
Peter Terium, CEO of Innogy SE, said it has made "great progress" in restructuring Npower in recent years, but the "competitive landscape and the uncertain political environment for energy retailers" makes it clear that it would be "better placed to offer value to our customers" through the merger with SSE.
Alistair Phillips-Davies, chief executive of SSE, said that it is "very proud of what we've delivered" but that the scale of changes in the energy market means that the merger with Npower will "ultimately better serve customers, employees and other stakeholders".