Companies House issues update on WebFiling security issue
Companies House has announced that it has resolved a security issue affecting its WebFiling service, discovered on 13 March 2026, which potentially allowed logged-in users to access and modify elements of other companies' details without consent. The service was closed at 1:30 pm on 13 March 2026 and restored at 9 am on 16 March 2026 following an investigation and independent testing. The investigation revealed that the issue, introduced caused during an October 2025 system update, may have exposed non-public company data, including dates of birth, residential addresses and email addresses. However, Companies House confirmed that passwords and identity verification data remained secure. The incident has been reported to the Information Commissioner's Office and the National Cyber Security Centre. Companies House has also asked companies to review their registered details and filing history to ensure they are correct, and stated that it will email each company's registered address with guidance on verification procedures.