Authentication codes: all you need to know

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Your company authentication code is a 6 character alphanumeric code provided by Companies House when your company is formed.  It is used to verify your authority to send information on behalf of the company and was introduced by Companies House as an additional security measure to ensure that only authorised persons could submit changes to company information.  As it is an electronic equivalent of the handwritten signature you cannot file online documents without your company authentication code.


How will I receive my company authentication code?

Companies House automatically allocate a web authentication code to every UK company when it is formed. They send a letter to the company registered office address displaying the authentication code as illustrated:


authentication code letter

However, if you have used Inform Direct to form your company then your authentication code will be available as soon as your company is incorporated. Once you have logged into our free company records management software you will find the authentication code has been retrieved electronically from Companies House and is displayed in the “Filing Details” section on the “Company” tab.  You will be able to get on with the process of submitting any company changes straightaway.


filing details

What should I do if I have lost my company authentication code?

Don’t worry.  If you have lost your company authentication code and would like to register to use Inform Direct, we can request the code for you.  Simply select the ‘Send me my code’ link when you register and we will request that Companies House send a reminder letter to your company registered office address.  You will usually receive it within three working days.


Can I change my company authentication code?

Yes, you can apply in writing to Companies House to change your company authentication code.  The letter of application should be written on company letter-headed paper and should include the following:

  • Your company name and registered office address.
  • Your company number.
  • The existing authentication code.
  • The new authentication code that you would like allocated to your company
  • The full name and email address of an authorised officer of the company.  This is an officer that is able to authorise the use of the specified authentication code.

Until you have received notification that your new authentication code has been accepted you should continue to use your original code.

If you are using our FREE company records management system then don’t forget to update your company details for your new authentication code.  Just click on the “Company” tab and select “Edit Filing Details”.  You can enter your new company authentication code and press “Save changes” to confirm.


Why might I change my company authentication code?

There are several reasons why you might find it beneficial to change your company authentication code:

  • You may wish to change it to something more memorable.
  • You may wish to use the same authentication code for all companies within the same group.
  • If you administer a number of limited companies then you may find it easier to change all their authentication codes to one standard code.
  • For security reasons (if you feel your authentication code is no longer secure).


Why has Companies House changed my company authentication code?

Companies House may change your authentication code if correspondence that they have sent to your company registered office address is repeatedly returned. This may occur if you have changed your registered office address and not notified Companies House.  You should notify Companies House of a change of registered office address using Form AD01 or if you have registered for free with Inform Direct, you can submit the change online using our company records management software.  Once Companies House has accepted your new registered office address you can request an authentication code reminder.


Why is my company authentication code not unique?

Companies are automatically allocated an authentication code when they are incorporated, but this code may be changed to something more memorable or to be the same as that of other group companies.  The ability to tailor the authentication code means that it is possible that other companies, unknown to you, may have an identical code.

However, this doesn’t usually represent a problem or a breach in security.  Only registered presenters can submit electronic forms to Companies House, and it is the registered presenters ID, used in conjunction with your unique company number and the authentication code which together give authority for changes to be made.


Getting started

If you have your company number and authentication code then you can register with Inform Direct to use our FREE company secretarial software now.  Inform Direct is the easiest way to manage your company records and to submit changes to Companies House instantly and securely.  If you would like to register to use Inform Direct but you do not have access to your authentication code, then simply select the ‘Send me my code’ link when you register and we will complete the process for you and ensure that a reminder is sent to your company’s registered office address.


2016 UK
Company Formation

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