Your company's first year: accounts, tax and filing dates

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A new limited company's first set of deadlines is the one most often missed, because the dates don't follow the pattern of later years. Here's how each one is set.

Checked against GOV.UK guidance on 16 October 2026. General information, not advice.

Your first accounting reference date

Companies House sets it automatically: the last day of the month in which the first anniversary of incorporation falls. GOV.UK's example is a company incorporated on 6 April 2025, which gets a reference date of 30 April 2026 and 30 April every year after. You can change it with form AA01.

Your first accounts deadline

First accounts covering more than 12 months

Due 21 months after the date of incorporation, or 3 months after the accounting reference date if that's later.

Later years

Due 9 months after the accounting reference date.

Late filing

£150 up to a month late, rising to £1,500 at over 6 months. See penalties.

Corporation tax works on a different clock

Telling HMRC

Tell HMRC the company is active within 3 months of starting to do business. That's not the incorporation date.

Accounting periods can't exceed 12 months

If the first accounts cover, say, 13 months, HMRC sees two corporation tax periods: the first 12 months, and the month left over. Each has its own return and payment date.

The dates

For each period, payment is due 9 months and 1 day after it ends, and the CT600 12 months after it ends. See corporation tax.

Your first confirmation statement

The first review period ends on the anniversary of incorporation, and the statement is due within 14 days of that. It's often the first filing a new company owes.

Check your own dates

Our company deadlines checker reads your accounts and confirmation statement dates straight from Companies House.

Sources

GOV.UK: Life of a company: accounts, Corporation Tax.

Get the first year right

We prepare first-year accounts and both CT600s together, so they tie out. See statutory accounts.