This blog will advise Directors and Persons of Significant Control on how to find their Companies House identity verification code.
If you did not apply for your Companies House identity verification code yourself, and you used an Authorised Corporate Service Provider (ACSP) to obtain your identity verification code, you will have received an email containing your personal code from noreply@companieshouse.gov.uk within 48 hours of the Authorised Corporate Service Provider making the application.
The Companies House website will state if you used an Authorised Corporate Service Provider to obtain your identity verification code under your director appointment.
For example

If you applied for your identity verification code yourself using Gov.uk One Login, please follow these instructions;
Log in to Gov.uk with the same email you used to register for your Companies House identity verification code- https://www.gov.uk/using-your-gov-uk-one-login

Click the grey sign-in box.
Enter your email and password (at least eight characters) on the screen, the text screen will then advise that a 6-digit verification code has been sent via text message to the phone number you provided. Enter the 6-digit verification code received via text message.
https://home.account.gov.uk/your-services

Once logged in you will see the Services screen – paste the below into your browser- https://identity.company-information.service.gov.uk/identity-verification/identity-verified-connected-to-account

You will then need to follow this link and log back in:
https://identity.company-information.service.gov.uk/user/account?lang=en
You will now be able to access your account, which includes your 11-digit IDV code.

In summary, we recommend that all directors and persons of significant control keep a note of their identity verification code, in the same way you would a national insurance number or self-assessment reference. The code is personal to you and can be used for multiple companies now and in the future. You should only have one identity verification code. You should share your identity verification code with anyone who makes filings on behalf of Companies that you are a director or person of significant control for, but no one else.