What does a new limited company have to file, and when?

If you've just set up a limited company for your marketing agency, here's what you need to file and when:

1. Company accounts - due 9 months after your year end
2. Company tax return - due 12 months after your year end
3. Corporation tax payment - due 9 months and 1 day after your year end (one day after your accounts are due)
4. Confirmation statement
5. Personal tax return

The first three are the deadlines for a normal year. A company's first year runs to different dates for accounts and Corporation Tax, which the second section below covers.

Don't know your year end?

Go onto Companies House, search your company name, and it'll tell you.

What are the deadlines in a normal year?

Gov.uk's table for private limited companies gives the same three: annual accounts filed with Companies House 9 months after the company's financial year ends, Corporation Tax paid 9 months and 1 day after the accounting period for Corporation Tax ends, and the Company Tax Return filed 12 months after that accounting period ends.

The accounting period is the time covered by the tax return, and gov.uk says it is normally the same 12 months as the financial year in the accounts. The 9 months and 1 day applies to taxable profits of up to £1.5 million. Above that, Corporation Tax is paid in instalments.

What is different in a company's first year?

Gov.uk gives a separate deadline for first accounts: 21 months after the date you registered with Companies House.

The reason is that first accounts usually cover more than 12 months. They start on the day the company was incorporated and end on the accounting reference date Companies House sets. In gov.uk's example, a company set up on 11 May gets an accounting reference date of 31 May the following year, so its first accounts cover 12 months and 3 weeks.

A Corporation Tax accounting period cannot be longer than 12 months, so gov.uk says you may have to file 2 tax returns to cover the period of your first accounts, with 2 payment deadlines. In its example, a company set up on 11 May 2024 with first accounts to 31 May 2025 has payment deadlines of 11 February 2026 and 1 March 2026. The dates also depend on whether the company started trading on the day it was set up or later. If you are still deciding whether a company is the right structure, see sole trader or limited company.

When is the confirmation statement due?

Confirms whether anything's changed over the year, such as your registered address, shareholders, or shareholding amounts. Even with no changes, you still need to file it.

Companies House guidance says the review period for a first confirmation statement ends 12 months after the date the company incorporated, and you can file up to 14 days after the review period has ended. After that you must file at least one every 12 months. It costs £50 online or £110 on paper, and all directors must verify their identity before the statement is filed.

Do you need a personal tax return too?

Due 31 January following the end of the tax year. For the 25/26 tax year, that's 31 January 2027.

That is the deadline for an online return. Whether you need to send one depends on your own income. Gov.uk says you may need to if you have untaxed income such as dividends, and that dividends above both your unused Personal Allowance and the £500 dividend allowance need to be reported to HMRC.

What happens if you miss a deadline?

Miss any of these and you're looking at fines, penalties, and interest.

For late accounts, Companies House penalties for a private limited company run from £150 for up to 1 month late to £1,500 for more than 6 months, and the penalty is doubled if accounts are late 2 years in a row. A late Company Tax Return is £200 at 1 day and another £200 at 3 months. HMRC may charge interest on Corporation Tax paid late. For the confirmation statement, you can be fined up to £5,000 and the company may be struck off.

Companies House can confirm your exact dates and let you subscribe for reminders when things are due.

The email reminder service is free and covers accounts and confirmation statements, with up to 4 people able to receive the reminder. For the bookkeeping behind these filings, see clean books.

Filing deadlines, fees and penalties change, and a first year depends on your incorporation and trading dates, so this is general information rather than advice on your company. If you want your dates mapped out, see how we work or talk to us.