For households, the immediate message is that nothing changes. Existing tariffs will remain in place, customer service arrangements will continue as normal, and both companies have promised advance notice of any future changes. The takeover nevertheless raises questions about competition, consumer choice and the growing concentration of Britain’s energy supply market.
What the E.ON and OVO Takeover Means for Customers
The acquisition brings together E.ON Next, which supplies approximately 5.6 million UK customers, and OVO Energy, which serves around 4 million. The combined business becomes Great Britain’s second-largest household energy supplier, behind Octopus Energy. E.ON has confirmed that customers of both companies will experience no immediate changes following completion of the transaction. All existing tariffs will be honoured in full, while established customer service channels will remain available.
The companies have also committed to giving customers sufficient notice before introducing any changes that might affect their accounts or services. The transaction was initially announced in May, with E.ON Next outlining plans to strengthen its residential energy business through the addition of OVO’s technology, capabilities and customer base.
Chris Norbury, chief executive of E.ON UK, said the company’s immediate priority remained supporting customers across both businesses. “We are pleased to have completed this acquisition but our first priority is unchanged: looking after our customers, in both E.ON Next and in OVO,” he said.
Norbury also described the market as “fiercely competitive”, arguing that greater scale and flexibility would help the company serve customers while adapting to changes in the energy system.
Three Energy Suppliers Now Control 74% of the Market
The takeover significantly changes the structure of Britain’s domestic energy sector, placing E.ON Next alongside Octopus Energy and British Gas as its three largest suppliers.
According to The Guardian, E.ON Next now accounts for approximately 25% of the household energy market, representing 13.45 million gas and electricity accounts. Octopus Energy leads with 26%, or 14.3 million accounts, while British Gas holds around 23%, equivalent to 12.5 million accounts.
Together, these companies control 74% of the market. Including EDF Energy and Scottish Power, five suppliers now account for approximately 90% of household energy supply across Great Britain.
The concentration marks a shift from the former “Big Six” structure, which dominated around 85% of the market in 2016. That year, a CMA investigation estimated that weak competition was costing customers between £1.4 billion and £1.7 billion annually.
According to Cornwall Insight’s energy supply lead, Tom Goswell, the consolidation brings both stability and potential concerns for households. “The big six have become the big three,” he said, noting questions about consumer choice and market competition.
Goswell acknowledged that larger suppliers could provide stability following the collapse of approximately 30 energy firms during the energy crisis. Yet he warned that fewer competitors could reduce incentives to lower prices or offer different products.
