German energy group E.ON has signed an agreement to acquire UK residential energy supplier OVO Energy for an undisclosed sum, a transaction that will position the combined entity as Britain's largest energy supplier by customer accounts, with approximately 9.7 million customers and a combined market share of around 28 per cent. The deal surpasses Octopus Energy's current market share of 25 per cent and is subject to approval from the Competition and Markets Authority, with closing anticipated in the second half of 2026.

The Guardian reported that E.ON currently serves approximately 5.6 million UK customers under its E.ON Next brand, while OVO held an 11.7 per cent share of the electricity market and 9.8 per cent of the gas market as of April 2026, making it the fourth-largest UK supplier ahead of the acquisition.

Chris Norbury, CEO of E.ON UK, said the deal is about customers being in control and new energy that works for everyone, and that E.ON chose OVO because it is a modern, digitally native business with great people and a shared belief that innovation is what can make energy affordable and sustainable for everyone.

OVO said the UK energy market has undergone significant change in recent years, particularly regarding financial resilience expectations and increasing regulatory oversight, and that these changes have altered the economics of the sector, particularly for standalone energy retail businesses, with the evolving market favouring greater scale and access to long-term capital.

OVO had made a loss in 2024 and had faced difficulties meeting Ofgem's financial resilience rules, which require suppliers to hold minimum capital buffers to manage market shocks.

Read more on E.ON's acquisition of OVO Energy.