In this article
Running a limited company means keeping track of deadlines from two organisations, Companies House and HMRC, plus your own personal tax return as a director. Each runs on a different clock, and most are set by your company's year end rather than the tax year.
This guide brings the key dates together. Your accountant should track them for you, but it's worth knowing what's coming.
Companies House deadlines
Annual accounts
A private limited company must file its accounts 9 months after its year end. A new company's first accounts are due 21 months after incorporation.
Late filing penalties are automatic. They increase the longer the accounts are late, and they double if the company was also late the year before.
Confirmation statement
At least once every 12 months, you must confirm that the information Companies House holds about your company is correct, including directors, shareholders, people with significant control and the registered office. You have 14 days after the end of each review period to file it.
Changes during the year
Changes such as a new director, a director leaving or a new registered office address must be reported within 14 days.
HMRC deadlines for the company
Corporation tax payment
For most small and medium-sized companies, corporation tax is due 9 months and 1 day after the end of the accounting period. Interest is charged on late payments. Larger companies pay in instalments during the year.
Company tax return (CT600)
The return is due 12 months after the end of the accounting period. Notice that the tax is due three months before the return. That catches out many directors.
Corporation tax rates
The main rate is 25% for profits over £250,000. Companies with profits of £50,000 or less pay the small profits rate of 19%, and marginal relief applies between the two. The limits are shared between associated companies.
A worked example
Here's how the main dates fall for a company with a 31 March 2026 year end:
| What | Who | Deadline |
|---|---|---|
| Annual accounts | Companies House | 31 December 2026 |
| Corporation tax payment | HMRC | 1 January 2027 |
| Company tax return (CT600) | HMRC | 31 March 2027 |
Payroll deadlines
If your company has employees, or pays its directors a salary through payroll:
- a Full Payment Submission goes to HMRC on or before each payday
- PAYE and National Insurance are paid by the 22nd of the following month if you pay electronically (the 19th by post). Very small employers may be able to pay quarterly
- employees receive their P60 by 31 May
- P11D forms for benefits in kind are due by 6 July, and the Class 1A National Insurance on them is due by 22 July if paid electronically
VAT deadlines
If the company is VAT registered, returns are usually quarterly. The return and payment are both due 1 calendar month and 7 days after the end of each VAT period, and must be filed through Making Tax Digital compatible software. Our VAT registration guide explains when you need to register.
Your own deadlines as a director
If you take dividends or have other untaxed income, you'll usually need to file a self assessment tax return:
- 5 October: register for self assessment if it's your first year
- 31 October: paper tax return deadline
- 31 January: online tax return deadline, and payment of the balance plus your first payment on account
- 31 July: second payment on account
How to stay on top of it all
- keep your bookkeeping current every month, so year-end accounts can be prepared early
- estimate your corporation tax during the year and set the money aside
- keep your Companies House details up to date as things change
- agree with your accountant who is responsible for each filing
Our monthly bookkeeping checklist shows the routine that makes year end straightforward.
Let us keep track for you
Liberty Financial manages these deadlines for limited companies across London, preparing accounts and returns early and telling you what's due well in advance. Every client has a dedicated account manager. Get in touch to talk it through, or see our outsourced bookkeeping service.
Deadlines and rates are based on HMRC and Companies House guidance at the time of writing. Check the latest position for your company before acting.
Frequently asked questions
What happens if my company accounts are filed late?
Companies House issues an automatic penalty that increases the longer the accounts are overdue, and the penalty doubles if accounts are late two years in a row. Persistent failure to file can lead to the company being struck off.
Is the corporation tax payment due at the same time as the tax return?
No. For most small and medium-sized companies, corporation tax must be paid 9 months and 1 day after the end of the accounting period, while the company tax return (CT600) is due 12 months after. Many people miss that the payment comes first.
Can I change my company's year end?
Yes, by notifying Companies House. You can shorten the accounting period as often as you like, but you can usually only lengthen it once every five years, and to no more than 18 months. Talk to your accountant first, as it affects your tax deadlines too.
When are a new company's first accounts due?
A new company's first accounts are due at Companies House 21 months after the date it was incorporated. After that, accounts are due 9 months after each year end.
Want this handled for you?
Our Southwark team keeps London businesses' books, tax and deadlines on track, with a dedicated account manager.
Written by
Peter Leshinsky
Founder, Liberty Financial, a firm of chartered accountants in Southwark supporting owner-managed businesses across London.
