A security issue has been found within the Companies House online filing system, potentially leaving confidential information for the entire Register at risk. While the situation has now been addressed, Companies House has advised companies to review their details.

What happened?

A technical flaw was discovered in the Companies House WebFiling system, used by companies and advisers to submit information and update records online.

The issue meant that someone logged into their own Companies House account could potentially view the private dashboard of another company by navigating the system in a particular way, without needing the Authentication Code for the company. In theory, this could have allowed them to see confidential details such as director information and company records and to submit filings or changes. 

The vulnerability did not require sophisticated hacking skills and was discovered by a third party, who reported it to Companies House. 

What did Companies House do?

Once Companies House were informed, they took the following steps:

• The WebFiling service was temporarily shut down on Friday 13 March 2026 while the problem was investigated.
• The system was secured, independently tested and brought back online on Monday 16 March 2026. 
• The incident has been reported to the Information Commissioner’s Office (ICO) and the National Cyber Security Centre (NCSC) as part of GDPR requirements. 
• Companies House is analysing system data to identify any anomalies or unauthorised activity. 

At the time of writing, there have been no confirmed reports that company details were altered, although the investigation is ongoing. 

Why companies are being asked to check their records

As a precaution, Companies House has advised businesses to review their company information and filing history to ensure everything appears correct.

This check will help confirm that:

• director details are accurate
• the registered office address is correct
• no unexpected filings or changes appear in the company’s history

What you should do now…

We recommend that company directors take a few minutes to review their company record on the Companies House website.

You can do this by:

1. Searching for your company on the Companies House register.
2. Reviewing the ‘Overview’ page for company details, in particular the Registered Office address.
3. Checking the officers section on the ‘People’ page, ensuring only the names you expect are listed.
4. Review the ‘Filing history’ to ensure there have been no unexpected filings.

This should only take a few minutes, and, if everything looks correct, no further action is needed.

If you notice anything unexpected or incorrect, you should contact Companies House immediately and follow their guidance.

Further updates from Companies House

Companies House has confirmed it will be emailing the registered email address for every company on the Register with further information about the incident and guidance on checking their records. 

If you receive a message from Companies House over the next few days, this is likely to be part of that communication process. 

Be aware though, this is likely to be a subject scammers pick up on, so there may well be some bogus variations of Companies House emails cropping up over the coming weeks. As always, be careful what links you follow and what sensitive information you’re asked to provide. We’ll keep you posted on any legitimate developments.

While issues like this are rare, it’s always worth keeping an eye on your company’s public record from time to time.

If you ever spot something that doesn’t look right, whether on Companies House or elsewhere, it’s best to investigate quickly.

If you have concerns…

If you do notice anything unusual when reviewing your company record or are unsure what the entries may mean, as ever, please get in touch and we’ll help if we can.