Company accounts filing deadline: Companies House dates, and keeping them in sync
Written by the Mipp team
Published: 19 October 2026 | Last checked against GOV.UK: 19 October 2026 | Accurate as of October 2026
A private limited company must file its annual accounts at Companies House within 9 months of the end of its financial year. A company's first accounts are due 21 months after it registered with Companies House. Separately, every company files a confirmation statement at least once every 12 months, within 14 days of the end of its review period. Late accounts get an automatic penalty, starting at £150.
This guide is for small UK practices looking after limited company clients. It covers the deadlines with worked 2026 and 2027 dates, the month-end rule that catches people out, and why the date on the Companies House register is the one to trust. It also covers the other register data a practice needs: SIC codes, directors and people with significant control.
Companies House deadlines at a glance
| Filing | Deadline | Example |
|---|---|---|
| Annual accounts | 9 months after the financial year ends | Year end 31 March 2026: due 31 December 2026 (Thursday) |
| First accounts | 21 months after the company registered | Registered 15 May 2025: due 15 February 2027 (Monday) |
| Confirmation statement | Within 14 days of the end of the review period | Review period ending 9 November 2026: due 23 November 2026 (Monday) |
Corporation Tax deadlines run alongside these, but they're set by HMRC, not Companies House. See our UK tax deadlines for 2026-27 for those.
The month-end rule
When a period is counted in months, the Companies Act says that if it starts on the last day of a month, it ends on the last day of the matching month (section 443). So the deadline can land on a different day number from the year end:
| Financial year end | Accounts due |
|---|---|
| 31 March 2026 | 31 December 2026 |
| 30 June 2026 | 31 March 2027, not 30 March |
| 30 November 2026 | 31 August 2027, not 30 August |
A year end in the middle of a month keeps its day: a 15 January 2026 year end is due on 15 October 2026.
The confirmation statement
The confirmation statement confirms that the information Companies House holds is up to date. It must be filed even when nothing has changed. The review period ends 12 months after incorporation for the first statement, and 12 months after the last statement's confirmation date after that. The company then has up to 14 days to file.
The statement is where many changes are reported. These include the registered office, directors and secretary, people with significant control (PSCs), shareholders and the company's SIC code. A company can be fined up to £5,000 and struck off if it doesn't file. A company can also file early, but it then chooses a new confirmation statement date, and the next review period starts from that date.
Why the register's date can differ from your calculation
The rules above give the normal deadline. The register can show something else, for example when:
- the company has been given an extension to its accounts deadline. A company must apply before the deadline, and only for an event outside its control.
- a confirmation statement was filed early, so the review period now runs from a new date.
The date shown on the register is the one Companies House will hold the company to. Any deadline list a practice keeps should be checked against it.
Late filing penalties for company accounts
| Time after the deadline | Penalty for a private limited company |
|---|---|
| Up to 1 month | £150 |
| 1 to 3 months | £375 |
| 3 to 6 months | £750 |
| More than 6 months | £1,500 |
The penalty is doubled if accounts are late two years in a row. Penalties for public limited companies are different. GOV.UK lists reasons an appeal may not succeed, and one is that it was the accountant's fault. So the practice's deadline list really matters.
SIC codes
A SIC (Standard Industrial Classification) code describes what a company does. Companies House publishes a condensed list of SIC codes for this, and a company updates its code through the confirmation statement. For a practice, the code is a quick check that the business you think you're advising is the one on the register. It's also a useful way to group clients by sector.
Directors, PSCs and identity verification
The register lists each company's directors, secretary (if it has one) and people with significant control. Since 18 November 2025, identity verification has been a legal requirement:
- Directors give their Companies House personal code as part of the company's next confirmation statement. Companies House won't accept the statement until every director has verified.
- PSCs must verify and give their personal code within a 14-day period. When that period runs depends on whether they're also a director, on their birth month, and on when they became a PSC.
Checking who is actually on the register is the first step to knowing whose identity needs verifying before the next statement.
How Mipp pulls in Companies House data
Mipp's accountancy workspace reads the public Companies House register so you don't have to retype it.
When you add a client. Search by company name or number under "Find on Companies House". Choose the company and Mipp fills in the client type, year end, incorporation date, confirmation statement date and registered office address, and keeps the company number and SIC codes. From those, it schedules annual accounts, confirmation statements and the other deadlines in the Compliance view, using the rules above, including the month-end rule.
Every day after that. For each client with a company number, Mipp checks Companies House about once a day. It stores the next accounts due date, the period those accounts are made up to, the next confirmation statement date and up to four SIC codes. When the register has a date for the next accounts or confirmation statement, Mipp uses it for that open deadline. Deadlines you've already marked as filed are left alone. If the two dates still differ, for example because you edited one, the deadline shows a note such as "Companies House says accounts due 31 Mar 2027, Mipp says 30 Mar 2027", so you can see which to correct.
SIC codes. The client card shows the company's SIC codes with their descriptions. If you left the client's industry blank, Mipp fills it from the first SIC description. An industry you typed yourself is never replaced.
Officers. On a company client's card, "Check Companies House" lists the current directors, secretaries and PSCs. Resigned and ceased officers are left out. Where one of them is already an individual client in Mipp, it suggests linking them to the company with that role, and nothing is linked until you confirm. People who aren't clients are listed, not added. Companies House shows only the month and year of birth, so a full date of birth you've recorded is kept. Linked people's UTR and National Insurance number stay visible on the company's card.
What Mipp doesn't do. It doesn't file accounts or confirmation statements, track identity verification or personal codes, or email your clients. The deadlines are a list you check, on the Accounts & CT tab of the Compliance view and as tasks on each client's board. You can also see them in Google, Outlook or Apple calendars through Mipp's private calendar feed. See how this fits into Mipp's practice management software for accountants.
Deadline dates in Mipp are a planning aid, calculated from the information you enter and the public register. Always check them against Companies House.
Frequently asked questions
When are company accounts due at Companies House?
Nine months after the end of the company's financial year. First accounts are due 21 months after the company registered with Companies House.
What if the year end is the last day of a month?
The deadline is the last day of the month nine months later. A 30 June 2026 year end is due on 31 March 2027.
When is the confirmation statement due?
Within 14 days of the end of the review period. The review period ends 12 months after incorporation, or after the confirmation date on the last statement.
What is the penalty for filing company accounts late?
For a private limited company, £150 up to 1 month late, £375 at 1 to 3 months, £750 at 3 to 6 months and £1,500 after that. It doubles if accounts are late two years in a row.
Do directors need to verify their identity before the confirmation statement?
Yes. Companies House will not accept a confirmation statement until all directors have verified their identity and given their personal code.
Keep every company's dates in step with the register
Look a client up once, and Mipp keeps their Companies House dates, SIC codes and officers in view. Start a 14-day free trial. You add a card to start, and nothing is charged for 14 days. Cancel anytime. See pricing for plans.
Sources
All checked on Monday 19 October 2026. Accurate as of October 2026.
- GOV.UK, Accounts and tax returns for private limited companies (deadlines, extensions). https://www.gov.uk/prepare-file-annual-accounts-for-limited-company
- GOV.UK, Running a limited company: annual accounts, penalties for late filing. https://www.gov.uk/annual-accounts/penalties-for-late-filing
- legislation.gov.uk, Companies Act 2006, section 443 (calculation of period allowed). https://www.legislation.gov.uk/ukpga/2006/46/section/443
- GOV.UK, Confirmation statement guidance (review period, 14 days, fine, early filing, SIC, identity verification). https://www.gov.uk/guidance/confirmation-statement-guidance
- GOV.UK, When you need to verify your identity for Companies House (last updated 30 July 2026). https://www.gov.uk/guidance/when-you-need-to-verify-your-identity-for-companies-house
- GOV.UK, Standard industrial classification of economic activities (SIC). https://www.gov.uk/government/publications/standard-industrial-classification-of-economic-activities-sic