Deal details and new market shares
E.ON Next completed its acquisition of OVO Energy on 8 October 2026 after clearance from the Competition and Markets Authority. The enlarged supplier now serves 9.6 million households, or roughly 25% of the Great Britain market. Octopus Energy holds the top spot at 26%, British Gas sits at 23%, and the three together supply nearly 75% of households.
Competition concerns raised
Tom Goswell of Cornwall Insight noted that the former Big Six have effectively become a Big Three. The CMA's 2016 investigation had already warned that weak competition could leave customers overpaying by around £1.7 billion a year. Chris Norbury, CEO of E.ON UK, pushed back, saying the market remains "fiercely competitive" and that the company's scale and flexibility would enable it to operate in customers' interests.
What households should watch
Fewer suppliers can mean less pressure on prices and fewer tariff choices, so it is worth checking your deal against the current price cap. Our energy comparison tool lets you see what is available in your area without leaving the site. Ofgem continues to monitor billing and customer service standards while the CMA keeps an eye on any further consolidation.
How the change affects switching
The concentration does not stop you switching, but it does make it more important to compare regularly. Smaller suppliers still exist, and some focus on renewables or fixed pricing that the larger groups may not match. Keeping an eye on your usage data and renewal dates remains the simplest way to avoid paying more than necessary.
