Where to find your Companies House company authentication code
On letters and returns
- Look for the letter from Companies House sent to the company's registered office address.
- If you can't get to that address, you can ask for the code to be sent to a home address instead.
From Companies House
- Sign in to Companies House WebFiling, or create an account.
- Follow the steps to request the code. If the company already has one, you're sent a reminder.
- Overseas companies request it through Find and update company information.
From your accountant
- If an accountant files for the company, they may hold the code. Ask them before requesting a new letter.
What it looks like
A letter from Companies House to the registered office showing the company name and number and a six-character code of letters and numbers.
If you've lost it
- Ask anyone who files for the company, such as your accountant, whether they hold it.
- Request it through WebFiling. It's posted to the registered office and can take up to 10 working days, longer at busy times, so don't wait until your accounts are due.
- Companies House won't email the code or give it over the phone.
Where you use it
You need the code to file through WebFiling, Find and update company information, or commercial software. Software also needs a presenter ID and presenter authentication code. A Government Gateway account can't be used to file at Companies House.
Authentication code and identity verification
Identity verification became a legal requirement at Companies House on 18 November 2025, part of the reforms brought in by the Economic Crime and Corporate Transparency Act. Directors and people with significant control (PSCs) usually verify only once, through GOV.UK One Login or an Authorised Corporate Service Provider such as an accountant, and receive an 11-character personal code.
The personal code belongs to the person, not the company, and Companies House treats it as separate from the company authentication code. Existing directors give their personal code in the company's next confirmation statement, and the company can't file that statement until every director is verified. The company code is still what authorises the filing itself.
Companies House says identity verification for people who file on a company's behalf will be introduced at a later date, and that you may then need your personal code to file. It hasn't set a date.
Keep it secure
Anyone with the code can change the company's details, so treat it like a bank card PIN. Share it only with people you trust. Change it in WebFiling if someone who shouldn't have it knows it, and tell everyone who files for the company, because the old code stops working.
Companies House asks you to report any request for the code that claims to come from Companies House.
Related
What else will you need?
- CS01CS01 confirmation statementThe CS01 confirmation statement tells Companies House that the information it holds about your company is up to date.
- ChecklistLimited company year-end checklistAt a limited company's year end, reconcile every bank and loan account, list unpaid invoices and bills, count stock, record asset purchases, review the director's loan account and check dividends were minuted.
- Where to find itFind your company UTRA company's Unique Taxpayer Reference (UTR) is a 10-digit number HMRC gives a limited company for Corporation Tax once it's set up.
- ChecklistIncorporation checklistTo incorporate a limited company you need an available name, a registered office address, at least one director and one shareholder, details of people with significant control, articles of association and a SIC code.PDF
Rather we did it?
Countify can handle this for you, for a fixed fee agreed upfront.
Questions
Frequently asked questions.
How long does a new authentication code take?
It's posted to the registered office and can take up to 10 working days, longer during busy periods.
Is the authentication code the same as my personal code?
No. The six-character authentication code belongs to the company and authorises filings. The 11-character personal code belongs to you once you've verified your identity.
Can I change the code to something easier to remember?
Yes, in WebFiling. Make it hard to guess, mixing letters and numbers, and tell anyone else who files for the company.
Can Companies House email me the code?
No. It's only sent by post, to the registered office or, if you can't get to that address, a home address.
Checked against GOV.UK on · Reviewed by Kamran Ishaq FCCA, Founder & CEO, on .
Sources: Company authentication codes for online filing (opens in a new tab) (Companies House); Verifying your identity for Companies House (opens in a new tab) (Companies House); When you need to verify your identity for Companies House (opens in a new tab) (Companies House); Companies House personal codes for identity verification (opens in a new tab) (Companies House); Notice served on bogus directors as Companies House changes come into force (opens in a new tab) (Companies House).
Countify is an independent accountancy practice. We aren't part of, or endorsed by, HMRC, Companies House or Revenue Scotland. Always file using the official form or service.
Contains public sector information licensed under the Open Government Licence v3.0 (opens in a new tab).