How to file dormant company accounts with Companies House

By DormantFile · Updated 27 May 2026

Every UK limited company must file annual accounts with Companies House, even if the company is dormant and has done nothing all year. For dormant companies, this means filing a simplified set of dormant accounts.

What are dormant company accounts?

Dormant company accounts confirm your company had no significant accounting transactions during the period. Under section 1169 of the Companies Act 2006, a company is dormant if it has had no "significant accounting transactions" — the only exceptions being shares taken by subscribers on formation and fees paid to Companies House.

What you need

Before you file, make sure you have:

• Company registration number — your 8-digit Companies House number.
• Companies House authentication code — a 6-character alphanumeric code sent to your registered office address. If you do not have one, you can request it from Companies House.
• Accounting period dates — the start and end date of the period you are filing for. Your accounting reference date determines these.

Note: these credentials are separate from your HMRC Government Gateway login, which you need for CT600 filing.

When is the deadline?

For private limited companies, annual accounts must be filed within 9 months of the end of the accounting reference period.

For example, if your accounting period ends on 31 March 2026, accounts are due by 31 December 2026.

For first-year accounts, the deadline is the later of 9 months after the end of the accounting period or 21 months from the date of incorporation.

We cover all the deadlines in our guide on dormant company filing deadlines.

What happens if you file late?

Companies House imposes automatic late filing penalties:

These penalties are non-negotiable and apply even if the company is dormant with nothing to report. If you file late in two consecutive years, the penalty doubles. We cover the full picture in our guide on late filing penalties.

How to file

You have three options:

1. File online via Companies House WebFiling

Go to the Companies House WebFiling service, log in with your authentication code, and follow the screens to file dormant accounts. It is free but takes 15--30 minutes if you have not done it before.

2. Use DormantFile

We submit your dormant accounts directly to Companies House via their official software filing API. Add your company, enter your authentication code, and file. Takes under 2 minutes. See how it works.

DormantFile handles dormant company filings only — if your company has traded or has transactions to report, you need accounting software or a professional.

3. Hire an accountant

An accountant can prepare and file your accounts on your behalf. This typically costs £80--£150 per company — appropriate if you need advice, but overkill if your company is genuinely dormant.

Do you also need to file a CT600?

Not necessarily. If your company is registered for Corporation Tax with HMRC, you also need to file a nil CT600 return. If it is not registered, you only need annual accounts. We explain how to check in our guide on whether you need a CT600.

DormantFile handles both filings from one dashboard, starting at £19/year.

Key points

• Every UK limited company must file annual accounts, even if dormant.
• Dormant accounts confirm no significant transactions occurred.
• Deadline: 9 months after your accounting reference date (21 months from incorporation for first accounts).
• Late penalties start at £150 and go up to £1,500. They double if late two consecutive years.
• You need your Companies House authentication code to file online. If you don't have one or it's lost, see our complete guide to the authentication code for how to request a replacement.