Companies House blunder

by Aitch, posted in Corporate Governance & Regulation

A Companies House blunder has raised concerns after a flaw in the WebFiling service briefly exposed sensitive company data. The issue, identified on 13 March 2026, meant that a logged-in user could potentially access and amend limited details of another company by carrying out a specific sequence of actions.

Companies House has stated that this system vulnerability was not available to the general public. Only users with authorised access codes who were already logged into the system could have exploited it. Nevertheless, the nature of the flaw meant that certain private information, such as dates of birth, residential addresses and company email addresses may have been visible. There was also a risk that unauthorised filings, including accounts and changes to director details, could have been submitted on another company’s record.

After identifying this issue, Companies House shut down the WebFiling service at 13:30 on 13 March to investigate. Following independent testing, the system was restored at 09:00 on 16 March. Companies House has said that passwords and identity verification data were not compromised, and that existing filed documents, such as accounts or confirmation statements, could not be altered.

The issue is believed to have arisen from a WebFiling systems update in October 2025. It has been reported to both the Information Commissioner’s Office and the National Cyber Security Centre.

Companies are now being urged to review their registered details and filing history carefully. While no confirmed misuse has been reported so far, Companies House is continuing to investigate. If a company has a concern, it should raise a complaint via the Companies House complaints page at www.gov.uk/government/organisations/companies-house/about/complaints-procedure and include evidence to describe the issue.

Source:Companies House | 16-03-2026
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Aitch
I'm Aitch, the Founder and CEO of CIGMA Accounting Ltd. As a Chartered Management Accountant and as a CIMA member, I've spent more than 16 years helping businesses, entrepreneurs, landlords, and individuals with tax planning, accounting, and HMRC compliance. As a chartered accountant in London, I'm passionate about making complex tax matters easier to understand and helping clients make confident financial decisions. Over the years, I've advised start-ups, SMEs, established companies, and high-net-worth individuals across a wide range of tax and accounting matters. My expertise includes Corporation Tax, Self-Assessment, Capital Gains Tax, Inheritance Tax planning, R&D tax relief, capital allowances, international tax, and resolving complex HMRC compliance issues. Whether clients need a business accountant, tax accountant, or strategic tax advisor, my focus is always on delivering practical advice that creates long-term value. One of my specialist areas is Making Tax Digital (MTD). I've worked extensively with businesses preparing HMRC's digital reporting requirements, helping them move to cloud accounting, improve financial processes, and adopt technology that makes compliance more efficient. I regularly speak at Making Tax Digital roadshows, industry events, and educational sessions in collaboration with Zoho Books, sharing practical insights into digital accounting, tax legislation, and the future of the profession. Many business owners looking for the best accounting firm in London are not simply searching for an accountant they're looking for trusted advice, responsive support, and long-term value. That's the approach I've taken in building CIGMA Accounting. My team and I work closely with businesses across London and the UK, providing accounting services, tax advisory, bookkeeping, payroll, VAT, company accounts, and strategic tax planning tailored to each client's goals. Through this website, I share practical guidance on UK taxation, Making Tax Digital, HMRC updates, Corporation Tax, Self-Assessment, and business finance. My aim is to provide reliable, straightforward information that helps business owners understand changing regulations, reduce compliance risks, and make informed financial decisions with confidence.
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