UK limited companies have three core deadlines: nine months for annual accounts at Companies House, twelve months for the Corporation Tax return at HMRC, and fourteen days for the confirmation statement at Companies House. First accounts after incorporation are different — they are due 21 months from the incorporation date. Late filing penalties scale from £150 up to £1,500, and they double if you file late in two consecutive years.
This guide gives you every key 2026 deadline in one place, with the rules, the penalty bands, and how to extend a deadline before it slips.
Annual accounts deadlines
Annual accounts must be delivered to Companies House by:
- Nine months from your accounting reference date (ARD) for a private limited company
- Six months from your ARD for a public limited company (PLC)
Your ARD is the last day of your financial year. Companies House sets it automatically at the end of the month of incorporation, so a company incorporated on 14 March 2024 has an ARD of 31 March each year. You can change your ARD using Form AA01, with constraints — you cannot extend it past 18 months, and you cannot extend more than once every five years (with exceptions).
First accounts: special rule
The deadline for first accounts is 21 months from the incorporation date, not nine months from the ARD. The first accounting period itself is typically longer than 12 months because it runs from incorporation to the ARD. For example, a company incorporated on 14 March 2024 with a 31 March ARD has first accounts running from 14 March 2024 to 31 March 2025, due by 14 December 2025.
Subsequent accounting periods are 12 months and the nine-month rule applies.
Corporation Tax (CT600) deadlines
The Corporation Tax return is filed with HMRC, not Companies House:
- CT600 filing deadline: 12 months after the end of the accounting period
- Corporation Tax payment deadline: nine months and one day after the end of the accounting period
So payment is earlier than filing. For a 31 March year-end, Corporation Tax is payable by 1 January, but the CT600 return is due by 31 March of the following year.
Larger companies with profits above £1.5 million pay Corporation Tax in quarterly instalments under different rules (the Quarterly Instalment Payments regime).
Confirmation statement deadline
A confirmation statement is filed at least every 12 months, within 14 days of the end of your review period. The review period runs from the date of incorporation or from the date of your last confirmation statement, whichever is later.
The 2026 fee is £50 for digital filing and £110 for paper, effective 1 February 2026. Once you pay the annual fee, additional confirmation statements within the same payment period are free.
For more on the differences between confirmation statements and the old annual return regime, see our guide on annual return vs confirmation statement.
Other deadlines: PAYE, VAT, and personal
If you employ staff, take a director’s salary, or are VAT-registered, you also have these recurring deadlines:
| Deadline | Rule |
|---|---|
| VAT return + payment | One month and seven days after end of VAT quarter |
| PAYE/NI payment (electronic) | 22nd of the month following the tax month |
| PAYE/NI payment (postal) | 19th of the month following the tax month |
| P60 to employees | By 31 May after end of tax year |
| P11D to HMRC | By 6 July after end of tax year |
| Class 1A NI on benefits | By 22 July (electronic) |
| Self Assessment online | By 31 January after end of tax year |
| Self Assessment paper | By 31 October after end of tax year |
| Self Assessment payment on account | 31 January and 31 July |
Directors of close companies often have Self Assessment obligations even when paid through PAYE, particularly where dividends are taken.
Late filing penalties
The penalty for late accounts at Companies House for a private company:
| How late | Penalty |
|---|---|
| Up to 1 month | £150 |
| 1–3 months | £375 |
| 3–6 months | £750 |
| Over 6 months | £1,500 |
Penalties double automatically if accounts are filed late in two consecutive years. PLC penalties are higher across all bands.
HMRC penalties for late CT600:
| How late | Penalty |
|---|---|
| 1 day | £100 |
| 3 months | A further £100 |
| 6 months | 10% of the unpaid Corporation Tax |
| 12 months | A further 10% |
Confirmation statement non-filing is a criminal offence rather than carrying a fixed penalty, but Companies House typically issues warnings and can move to strike off the company.
How to extend a deadline
Companies House allows extensions for accounts filing only in limited circumstances, by application before the deadline expires. Reasons must be exceptional, such as an unforeseen event outside your control. Routine reasons (busy, accountant unavailable) are not accepted.
Apply via the Extend Your Filing Deadline service on GOV.UK. Allow time for processing, as last-minute applications are not always granted.
HMRC does not formally extend the CT600 filing deadline, though it can apply reasonable excuse to penalties on appeal.
For step-by-step help on actually filing, see how to file accounts with Companies House.
Key takeaways
- Private limited company annual accounts: 9 months from ARD
- PLC annual accounts: 6 months from ARD
- First accounts after incorporation: 21 months from incorporation date
- Confirmation statement: 14 days after end of review period
- CT600: 12 months after end of accounting period; tax payable 9 months and 1 day after period end
- Companies House late accounts penalties: £150 to £1,500, doubled for consecutive years
Frequently asked questions
When are my first accounts due? Twenty-one months from the date of incorporation. The first accounting period is typically longer than 12 months because it runs from incorporation to your ARD.
What happens if I miss the accounts filing deadline? A late filing penalty applies automatically: £150 for up to one month late, £375 for one to three months, £750 for three to six months, and £1,500 for more than six months. Penalties double if you file late in two consecutive years.
Can I extend my Companies House filing deadline? Yes, but only in exceptional circumstances and only if you apply before the existing deadline expires. Routine reasons such as a busy schedule or an unavailable accountant are not accepted.
When is Corporation Tax due? The CT600 return is due 12 months after the end of the accounting period. The tax itself is payable nine months and one day after the end of the accounting period.
Do confirmation statement deadlines differ from accounts deadlines? Yes. The confirmation statement deadline is 14 days after the end of your review period (which runs from incorporation or last filing). It is independent of your accounts ARD.
Useful resources
Companies House — Late filing penalties https://www.gov.uk/government/publications/late-filing-penalties
Companies House — Extend your filing deadline https://find-and-update.company-information.service.gov.uk/extensions
GOV.UK — Corporation Tax deadlines https://www.gov.uk/corporation-tax