How to Order Your Companies House Authentication Code

For a limited company director, an authentication code can feel like a small detail until you need to file accounts, submit a confirmation statement or appoint an accountant. Knowing how to order your Companies House authentication code online means you can get the process moving quickly, but there is one point that catches many directors out: the code itself is normally sent by post to your company’s registered office.

It is not an HMRC login, a Government Gateway code or a personal identity verification code. It is a separate security code used to confirm that the person filing information for the company has authority to do so. Treat it like a signature for your company’s online filings.

What is a Companies House authentication code?

A Companies House authentication code is a six-character security code for your limited company. It is used when filing certain company information online, either by you as director or by an authorised agent acting for the company.

You may need it to file statutory accounts, a confirmation statement, changes to directors or registered office details, and other documents through Companies House online services. Your accountant may also ask for it when taking over responsibility for company filings.

The code belongs to the company, not to an individual director. That distinction matters. If there are two directors, both may need access for legitimate company administration, but it should not be shared casually with staff, former business partners or anyone whose authority you cannot verify.

How to order your Companies House authentication code online

To request the code, use the official Companies House online service for requesting an authentication code. You will need your company number. This is the eight-digit number, or the relevant combination of letters and numbers, assigned when the company was incorporated. It is not your UTR for Corporation Tax and it is not your VAT number.

Search for your company using the company number or company name, select the correct business and follow the on-screen request process. Check the registered office address shown carefully before you submit the request.

Companies House will usually send the code by post to the company’s registered office. For most straightforward requests, it should arrive within a few working days, although post delays can happen. You cannot normally choose to have a new code sent by email simply because you need to file urgently.

This postal process is deliberate. It helps protect companies from unauthorised online changes. If someone could request the code to any address or inbox, it would be far easier for a third party to take control of a company’s filing access.

Before you request it, check the registered office

The biggest practical issue is an out-of-date registered office address. Perhaps the company was formed at an old home address, a previous accountant’s office, a formation agent’s address or a serviced office that you no longer use. If the address on the public register is wrong, the authentication code will go there.

Do not assume Companies House will redirect it because you have updated your address with HMRC. HMRC and Companies House are separate bodies, and changing one record does not automatically update the other.

If the registered office is still controlled by a former accountant or formation agent, contact them promptly and ask whether they hold your company post. A professional firm should have a process for dealing with correspondence, but you should not rely on that arrangement indefinitely. It is usually better for a trading business to keep its registered office details current and ensure directors can access the post sent there.

If the address is wrong

You may be able to change the registered office address through Companies House, but in many cases you will need the existing authentication code to make the change online. That can create a frustrating loop if the code is being posted to the wrong place.

Your options depend on the company’s circumstances. If you can still access the old address, recover the post first. If you cannot, you may need to use the appropriate Companies House process to correct the registered office details and provide evidence or supporting information where required. This is one of those situations where getting advice early can save time, particularly if accounts or a confirmation statement are close to their deadline.

Do not ignore a filing deadline while waiting for the problem to resolve itself. Late filing penalties for company accounts can apply automatically, even where the delay started with an admin issue.

What to do when the code arrives

When the letter arrives, keep the code in a secure place that the directors can access. A password manager or a controlled company records folder is generally better than leaving it in a van, on a desk or buried in someone’s personal email inbox.

If your accountant handles your statutory filings, provide the code through a secure agreed method. Avoid putting it in an open social media message or sending it to an address you have not checked. A genuine accountant should be clear about why they need the code and how they will use it.

It is sensible to record who has been given access. This is particularly useful for family companies, construction businesses with several working directors, or firms where admin is shared between the office and an external bookkeeper. Clear responsibility prevents the common last-minute question: “Who has the Companies House code?”

Lost code, changed accountant or suspected misuse

If you have lost the authentication code, request a replacement online. The new code will again be sent to the registered office. You should also consider requesting a replacement if a director leaves, you change accountants, or you think the code may have been disclosed to somebody who should no longer have it.

Changing accountants does not automatically mean the old firm can no longer access company information. You should deal with the practical handover: collect company records, confirm filing responsibilities, remove or change access where appropriate, and make sure the new adviser has what they need before the next deadline.

If you suspect fraud or an unauthorised change to your company, act quickly. Review the company record, secure access to your registered office post and seek professional guidance. Depending on what has happened, you may also need to contact Companies House directly and consider whether wider fraud reporting is required.

Do not confuse it with identity verification

Companies House identity verification requirements are being introduced as part of wider company law reforms. These requirements concern verifying the identity of directors and other relevant individuals. They are separate from the company authentication code used for filing.

You may therefore need more than one type of access or reference number as a director. Your personal verification details confirm who you are. The authentication code helps confirm authority to file for the company. Keeping these records organised is becoming part of good company housekeeping, not just an annual task when accounts are due.

A practical note for busy directors

For owner-managed companies, the code is often only noticed when something needs filing urgently. That is understandable if you are running jobs, managing staff, driving, quoting for work or dealing with customers. But it is worth checking now that your registered office is correct and that the people responsible for compliance can access the code.

If you are unsure what needs filing, when it is due or whether your accountant has the right authority to act, Short And Sons Accountants can help bring the paperwork into order. A few minutes spent checking your company records now can prevent a late filing penalty or a far more stressful chase when deadlines are close.

Keep the authentication code secure, keep the registered office address up to date, and make sure responsibility for company filings is clear. Those simple habits give you more time to concentrate on the work that actually earns the money.