In its quarterly Domestic Energy Market Share Survey Cornwall Insights said Octopus now serves 12.9 million meters, around a quarter of the UK total. Octopus led the switching market in 2024, with nearly one million customers choosing to join from other suppliers.

British Gas has lost its crown as Britain’s largest household energy supplier after being overtaken by Octopus Energy.

Three suppliers have been crowned as Which? Recommended Providers - but some of the biggest energy firms, including British Gas, Scottish Power and Ovo Energy, came bottom of the rankings

Octopus Energy, Utility Warehouse and 100Green have been named as Which? Recommended Providers in the consumer champion's annual energy firm survey. On the other hand, some of the biggest firms, including British Gas,