Last updated: 14 October 2026
When are company accounts due, and what are the late filing penalties?
A private limited company must file its annual accounts with Companies House within 9 months of its accounting year end. First accounts are due 21 months after the date of incorporation. If you file late, Companies House charges an automatic penalty of £150 to £1,500, which doubles if you were also late the previous year. Separately, the company tax return (CT600) is due with HMRC 12 months after the end of the accounting period, and corporation tax is usually payable 9 months and 1 day after the year end.
Key deadlines
| Filing | Deadline |
| Companies House accounts (private company) | 9 months after year end |
| First accounts after incorporation | 21 months after incorporation |
| Public company accounts | 6 months after year end |
| Corporation tax payment (most companies) | 9 months and 1 day after year end |
| Company tax return (CT600) | 12 months after year end |
| Confirmation statement | At least once every 12 months, within 14 days of the review date |
Companies House late filing penalties
| How late | Private company | Late two years running |
| Up to 1 month | £150 | £300 |
| 1 to 3 months | £375 | £750 |
| 3 to 6 months | £750 | £1,500 |
| More than 6 months | £1,500 | £3,000 |
HMRC penalties for a late CT600
- 1 day late: £100
- 3 months late: another £100
- 6 months late: HMRC estimates the tax and adds 10% of the unpaid tax
- 12 months late: another 10% of the unpaid tax
- Late three times in a row: the £100 penalties become £500 each
Example
Halton Joinery Ltd has a year end of 31 March 2026. Its accounts are due at Companies House by 31 December 2026, corporation tax is due by 1 January 2027, and the CT600 by 31 March 2027. If it files its accounts on 15 February 2027, it gets a £375 penalty, as it’s more than a month but less than 3 months late.
Filing changes
The joint online service for filing accounts and the company tax return together closed on 31 March 2026. Companies now file accounts using Companies House software or commercial software, and file CT600s with HMRC separately. Companies House is also moving towards software-only filing for all accounts.
Can you appeal?
Companies House only accepts appeals in exceptional circumstances, such as serious illness or a fire. Pressure of work, an accountant’s mistake or not knowing the deadline are not accepted.
Extensions
You can apply for an extension before the deadline if something outside your control, such as illness or a natural disaster, prevents filing on time.
Changing your year end
Shortening your accounting period changes your filing deadline. If the new deadline has already passed, a penalty applies automatically.
Practical tips
Set up reminders for each deadline as soon as your year end is fixed. Send your records to your accountant soon after the year end, so the accounts and tax return can be prepared in good time and you know your corporation tax bill well before it is due.
Frequently asked questions
Do dormant companies need to file?
Yes, dormant accounts are still required.
Can directors be prosecuted?
Yes, failure to file is a criminal offence.
Will the company be struck off?
Companies House can begin strike-off if accounts aren’t filed.
Is the penalty tax-deductible?
No.
Related: dormant companies, closing your company and late payment interest on corporation tax.
Talk to Accotax
Want this handled for you? Our team at Accotax can help with company accounts and filing. See our small business accountants service, or contact us for a free, no-obligation quote.
This page is general guidance based on HMRC rules for the 2026/27 tax year, checked against gov.uk on 14 October 2026. It is not personal advice, so speak to an accountant about your own situation.
