Guidance

Company authentication codes for online filing

How to request and manage the authentication code you'll need for filing company information online with Companies House.

The authentication code is a 6 digit alphanumeric code issued by us to each company. The code is used to authorise information filed online and is the equivalent of a company officer’s signature.

You’ll need a code to file using our online services or third-party software.

Don’t wait until you’re due to file to request your code and risk it being too late. Delivery could take longer than usual, due to the high volumes of post during the holiday period.

How to get your code

Request your code now - it’s sent by post to the company’s registered office and can take up to 5 days to arrive.

Watch a video to see how easy it is to register and order your code.

If you’re new to the service, you’ll need to:

  1. Register your email address and password.

  2. Select ‘Request an authentication code’.

  3. Enter your company registration number.

  4. Select ‘Request code’.

Screenshot of web filing screen

Your code will be sent by post to your company’s registered office - if your company already has a code, a reminder will be sent.

For security reasons the code can’t be sent by email or provided over the phone.

Using your code

The same authentication code can be used for your company whether you’re using our online filing services or third-party software.

To use our online filing services you’ll also need to register your email address and password.

To file using third-party software you’ll need to set up an online filing account to get a presenter ID and presenter authentication code.

You can’t use your Government Gateway account to file information online with Companies House.

Changing or cancelling your code

To change or cancel your code use the ‘Company authentication’ section of our online filing service.

You can change your code to something more memorable, but don’t make it easy to guess.

Tell anyone else who files online on behalf of your company (such as an accountant) that you're changing your code, or they won't be able to file.

Looking after your code

You should treat your company’s authentication code with the same care you would your bank card PIN number. Anyone who knows your code has the ability to change your company’s details online.

Here’s some tips for looking after your authentication code:

  • mix letters and numbers so your code isn’t easy to guess
  • only share your code with someone you trust to file information for your company
  • if your code becomes known by someone not trusted then change it
  • change your code if it’s known by someone no longer authorised to file information for your company (such as staff who’ve left your company or your previous accountant)

We’ll never ask you what your authentication code is over the phone.

If you’re contacted by someone asking for your code and claiming to be from Companies House, you should report it to us immediately.

Published 18 May 2015
Last updated 6 December 2017 + show all updates
  1. Guidance added for the Christmas holiday period.
  2. Screenshot added.
  3. Welsh translation added.
  4. First published.