The security issue was identified on 13 March and Companies House WebFiling service was immediately shut down at 1.30pm last Friday.

The breach meant logged-in users of the WebFiling service could effectively access and change some entries on another company’s details without their consent after simply pressing back click from within their own company’s dashboard on Companies House.

Andy King, chief executive of Companies House, said: ‘This was not accessible to the general public. Only users with an authorised code and logged in to the service could have performed this action.’

He added investigators identified the security breach ‘issue was introduced when we updated our WebFiling systems in October 2025’ when the Government Gateway access protocol was replaced.

T