Companies House Data Breach: What It Means for Small Business Owners

A Complete Guide by Direct Assist – Chartered Certified Accountants

Published: 25 March 2026

Recent reports have highlighted a serious security vulnerability within Companies House, which may have exposed sensitive data of up to 5 million UK company directors.

While there is currently no confirmed evidence of widespread misuse, the scale of the issue has understandably caused concern among small business owners and limited company directors.

Although the issue has now been resolved, this incident is an important reminder that digital security should never be overlooked, even when dealing with official government systems.

1. What Happened?

The issue stemmed from a vulnerability within the Companies House WebFiling system.

It allowed logged-in users to:

• Access data belonging to other companies
• View sensitive director information
• Potentially edit company records

This included personal data such as:

• Director names
• Dates of birth
• Residential addresses
• Email addresses

The vulnerability was discovered when a user attempted to file for another company and, by navigating back through the system, gained access to a different company’s dashboard.

Importantly, this was not a sophisticated cyberattack, but rather a flaw in the system that had been introduced during an update in October 2025.

2. What Was the Risk?

Because of this vulnerability, unauthorised users could have:

• Viewed confidential company and director information
• Made changes to company records
• Submitted or deleted filings
• Altered director details

Even though there is no confirmed malicious activity, the potential for misuse has raised concerns about data protection and system security.

3. What Action Did Companies House Take?

Once the issue was identified, Companies House acted quickly:

• The WebFiling service was temporarily shut down
• An investigation was launched immediately
• The vulnerability was fixed within a few days
• The system was safely restored

Companies House confirmed:

• There is no evidence of data misuse
• Passwords were not compromised
• The issue has now been fully resolved

They also issued a formal apology and reassurance to affected users.

4. What Should You Do Now?

Even though the issue has been fixed, it’s important to take a proactive approach to protecting your business information.

1. Review Your Company Records

Log into your Companies House account and check that:

• Your director details are correct
• No unauthorised changes have been made

2. Check Your Filing History

Look through your filing history carefully and watch for:

• Unexpected submissions
• Unknown changes to records

3. Stay Alert for Suspicious Activity

Be cautious of:

• Unusual emails or correspondence
• Unexpected calls requesting information
• Any unfamiliar activity linked to your business

4. Seek Professional Support

Working with an accountant ensures your records are:

• Accurate
• Up to date
• Fully compliant with HMRC and Companies House

At Direct Assist Accountants, we can help review your company records and identify any potential issues before they become serious problems.

5. How Direct Assist Accountants Can Help

Moving away from spreadsheets is one of the best decisions you can make for your business, but having the right support makes all the difference.

At Direct Assist Accountants, we help small businesses and self-employed professionals transition smoothly to cloud accounting software.

Our services include:

• Setting up and managing FreeAgent or Xero

• Helping you stay compliant with Making Tax Digital

• Providing real-time financial insights and tax planning

• Ongoing support from a dedicated accountant

We don’t just help with compliance—we help you understand your numbers and make better business decisions.

6. Why This Matters for Small Business Owners

This incident highlights an important reality: even official platforms are not immune to errors or vulnerabilities.

For small business owners, this reinforces the importance of:

• Regularly checking your company records
• Keeping your financial and legal data organised
• Having professional oversight of your accounts

Taking these steps helps protect your business from unnecessary risks and gives you peace of mind.

7. Ready to Make the Switch?

If you’re still relying on spreadsheets and want a more efficient way to manage your finances, now is the time to move to cloud accounting.

Get in touch with Direct Assist Accountants today to learn how we can help you transition smoothly and take control of your business finances.