If you run a limited company, the recent Companies House WebFiling security issue deserves close attention. It is also a reminder that keeping your Companies House record accurate and monitored is part of protecting your business, not just meeting an admin requirement.
This was not a minor glitch. It was a genuine security flaw that meant certain private information could potentially be seen by other logged-in users. For business owners and directors, that raises understandable concerns about privacy, fraud, and the reliability of company records.
The good news is that the issue has now been fixed. Just as importantly, some of the most sensitive information, including passwords and identity verification documents, remained secure. Even so, this is the kind of incident that shows why Companies House details should be reviewed regularly and managed properly, especially when a business wants to reduce risk rather than react to problems after the fact.
What Happened
According to Companies House, the flaw was introduced during a WebFiling system update in October 2025 and was fixed on 16 March 2026 after the service was temporarily taken offline. The issue came to wider attention after it was highlighted by Tax Policy Associates and later covered in more technical detail by The Register.
How the flaw worked
In simple terms, a logged-in user could attempt to file for another company, fail the security check, and then use their browser’s back button to access that company’s private dashboard.
That should never have been possible.
Companies House has said the flaw was not available to the general public, and that access was limited to logged-in WebFiling users viewing records one company at a time. Even so, the weakness created a clear risk and justified the swift shutdown of the service while it was patched.
What information was exposed
The data that may have been visible included:
full dates of birth
residential addresses
company email addresses
Importantly, Companies House has confirmed that the following were not affected:
passwords
passport information or other identity verification data
existing filed documents such as accounts or confirmation statements
The Risks to You
For directors and business owners, the main concern is not just privacy. It is what someone could do with the information they saw. This is why proper oversight of your Companies House details matters. Keeping records accurate, checking filing activity, and spotting anything unusual early are practical safeguards, not box-ticking exercises.
Privacy and identity risk
Residential addresses and full dates of birth are exactly the sort of details criminals can use for impersonation, phishing, and social engineering. On their own, they may not open every door, but they can make fraud attempts look far more convincing.
Risk of unauthorised filings
Companies House has also confirmed that unauthorised filings may have been possible, including changes to directors or accounts. That is where this moves from being embarrassing for Companies House to potentially serious for businesses.
A fraudulent filing could create confusion, reputational damage, and a significant administrative headache. In the worst case, it could be part of an attempt to hijack control of a company record.
Next Steps
This is the part that matters most. If you are a director or responsible for company filings, take a few minutes now to review your record.
Check your company details immediately
Log in to Companies House and review:
your filing history
director details
registered office information
company email addresses
anything else that looks unfamiliar or out of place
If something does not look right, raise it with Companies House straight away.
Sign up for the Follow service
If you have not already done so, use the Companies House Follow service. It is a simple way to receive alerts when changes are made to a company record. In situations like this, early warning is far better than finding out weeks later.
Keep a close eye on suspicious activity
Be cautious with unexpected emails, identity requests, or messages that appear to reference company details that are not normally public. A little scepticism here is healthy.
As your accountants, we are already monitoring the records of our managed clients and keeping a close eye on unusual activity. Reviewing Companies House details, checking filing history, and helping clients keep official company details accurate is part of good financial housekeeping and good business protection.
Even so, vigilance still matters. A quick check now could save a lot of hassle later.
If you are unsure whether your company record is up to date, or you want a second pair of eyes on what has been filed, get in touch. We can help you review key details, check for anything unexpected, and make sure your Companies House record reflects the true position of your business.
To speak to Volarti, call 01908 893610, email michelle@volarti.co.uk, or use the contact form.
Volarti can help
If you are unsure whether your company record is up to date, or you want a second pair of eyes on what has been filed, get in touch. We can help you review key details, check for anything unexpected, and make sure your Companies House record reflects the true position of your business.
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