Filing your company accounts with Companies House

Every limited company files annual accounts with Companies House, even if it made no money. How much you have to file depends on your company’s size. Here’s what goes in, when it’s due, how to file it, and how it differs from the accounts you send HMRC.

Last checked against GOV.UK on 29 September 2026.

A4O Accounts files your accounts and CT600 from the same figures. Get started free, no card required.

Which accounts your company files

What you file depends on your company’s size. A company is in a size band if it meets at least 2 of the 3 conditions. For accounting periods that begin on or after 6 April 2025, the limits are:

A company over the medium limits is large. After your first year, you have to meet the conditions in that year and the year before to stay in a band.

What goes in them

Your statutory accounts are a balance sheet, a profit and loss account, notes to the accounts and, unless you’re a micro-entity, a directors’ report. Some companies also need an auditor’s report. The board approves the accounts, and a director signs the balance sheet and prints their name.

What you have to send Companies House can be less than that:

• Micro-entities can prepare simpler accounts and file only the balance sheet, with its footnotes. No profit and loss account and no directors’ report.
• Small companies don’t currently have to deliver the directors’ report or profit and loss account. Accounts filed this way are often called filleted accounts. A small company can also file abridged accounts, with a shorter balance sheet.
• Medium and large companies file everything, including the profit and loss account and directors’ report.
• Dormant companies don’t need a profit and loss account or directors’ report. See dormant company accounts.

If your company claims exemption from audit as a small company, the balance sheet must carry a statement saying so, under section 477 of the Companies Act 2006.

When they’re due

A private company has 9 months from its accounting reference date, the end of its financial year, to file.

First accounts work differently. The deadline is the later of 21 months from the date the company was incorporated, or 3 months from the accounting reference date. That’s the one new companies most often miss, so check it on your company’s Companies House record.

Your authentication code

The company authentication code is a 6-character code Companies House issues to each company. It stands in for a director’s signature when you file online or through software.

Companies House posts it to your registered office address, or your home address if you can’t get to that one. It can take up to 10 working days to arrive, and Companies House won’t give it out by email or phone. If you don’t have it, ask for it well before your deadline. There’s more in our help page on the Companies House authentication code.

Ways to file today

• Software. Accounting software files directly to Companies House, with the accounts tagged in iXBRL.
• Companies House’s online service. It accepts dormant accounts for companies that have never traded, micro-entity accounts, abridged accounts and small full accounts. You need a Companies House account and the authentication code.
• Paper. Still possible for now.

From April 2028, the online service and paper filing for accounts stop. Every company will need commercial software, abridged accounts end, and small and micro companies will have to file a profit and loss account, with an option not to publish it. Read software-only accounts filing from April 2028.

Late filing penalties

The penalty is automatic and doubles if your accounts are late two years in a row. Appeals rarely succeed on grounds like not knowing the deadline or your accountant’s mistake.

How this differs from the accounts you send HMRC

Your accounts also go to HMRC, as part of your Company Tax Return (CT600). The differences:

• What’s sent. HMRC gets your full statutory accounts, including the profit and loss account, even if Companies House gets a shorter version. The return also includes a tax computation, because taxable profit is different from the profit in your accounts.
• Deadline. The CT600 is due 12 months after the end of the accounting period, not 9. Corporation Tax itself is usually due 9 months and 1 day after. See Corporation Tax deadlines.
• How you file. HMRC’s free online service closed on 31 March 2026, so the CT600 already goes through software. See how to file a CT600.

The figures come from the same books, so it makes sense to prepare both together.

Doing it in software

A4O Accounts prepares your accounts and CT600 from the same books, and files the accounts with Companies House and the return with HMRC. It covers micro-entity, small, full FRS 102, audited and dormant accounts, filed as full, filleted or abridged. You enter the authentication code once and it’s stored encrypted, and you can send a test submission before the real one. Our help page on filing annual accounts with Companies House walks through it, and Companies House filing software shows what’s covered.