Your company authentication code: what is it and why you do need to keep it secure?

June 5, 2018 | Posted by Sonal Agarwal | Accounting, Business Advice, Taxation, Whitepapers,

What is an authentication code?

If your company was incorporated through an agent, you may be unaware of your company authentication code.

When you form a new company, Companies House issue a 6 digit alphanumeric code. This is known as your company authentication code, and it allows an authorised person to file forms with Companies House. In a way, it acts as the company’s digital signature.  

Companies House encourages new companies to form via their online process. This is because it is cheaper and faster:

  • On paper, it will cost £40 and almost a week to form a new company
  • Online, it takes just 24 hours and costs £12.
  • All subsequent filings are cheaper and faster.

Therefore, most agents register the company for a web filing service (known as Protected Online Filing- PROOF scheme) upon incorporation. To log in to a company’s web filing account, you need the authentication code.

What happens if you’re not aware of the code?

 If you’re a director or shareholder and you’re unaware of the code and what it means, it could cause complications for you in the future.

We encountered this problem with a new client recently:

  • The agent registered the company on behalf of two individuals. They were equal shareholders and also directors in the new company.
  • The company was registered at the agent’s office address and even the residential addresses of the directors were the same.
  • When the directors had a disagreement with the agent, he simply stopped taking their calls or replying to their emails.
  • With no contact with the agent, the directors couldn’t obtain the authentication code and change any company details.
  • Because you cannot deregister a company for web filing without the authentication code, Companies House passed the matter to their anti-fraud team.
  • It took a long time to convince them of the situation and obtain a new authentication code. 

Changing your code 

You can change an authorisation code through the web filing services. To prevent fraud, Companies House will not change your authentication code over phone.

If you have lost it, you can request for a new code to be sent to the company’s registered office address.

If your registered address has changed but hasn’t been officially updated, you can request that the code is sent to a director’s residential address, as held in official records. 

Looking after your code

 You should treat your company authentication code with the same care you would your bank PIN number. Anyone who knows your code has the ability to change your company’s details online, so it’s important that you keep it safe.

Some points to consider:
  • Is your code easy to guess? 
  • Have you only shared your code with person you trust to file information for your company?
  • Does someone you don’t trust know your code?
  • When someone leaves your company (that knows the code), or you change accountants, do you change the code? 
  • Do you ensure the code isn’t changed without your permission?


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