Companies House – WebFiling Security Issue

Companies House has confirmed that it recently identified a security vulnerability affecting its WebFiling service. The service was suspended as a precaution but has since been secured and restored.

The issue identified on 13 March 2026 meant that logged-in users may have been able to access or amend limited information relating to other companies without their consent. Amendable data included directors’ dates of birth, residential addresses and company email addresses. It may also have been possible for unauthorised filings – such as accounts or changes of director – to have been made on another company’s record.

The vulnerability arose from an update to the WebFiling service in October 2025 as part of the wider reforms introduced under the Economic Crime and Corporate Transparency Act 2023. For more on these reforms, see our blog post here.