Dormant company filing deadlines explained
By DormantFile · Updated 28 March 2026
Dormant companies have the same filing deadlines as trading companies. Missing them triggers automatic penalties. Here is how the deadlines work.
If you just want the dates, our free dormant deadline calculator works them out for you from your incorporation date or ARD — accounts, CT600, and confirmation statement in one go.
Annual accounts (Companies House)
Annual accounts must be filed within 9 months of the end of your accounting reference period.
Your accounting reference date (ARD) is the date your annual accounts are prepared up to. By default, it is the last day of the month in which the anniversary of your company's incorporation falls.
Example: Company incorporated 15 June 2024. Default ARD = 30 June. First accounting period ends 30 June 2025. Accounts due by 31 March 2026.
CT600 (HMRC)
If your company is registered for Corporation Tax, the CT600 must be filed within 12 months of the end of the accounting period.
Using the same example: accounting period ends 30 June 2025, CT600 due by 30 June 2026.
The CT600 deadline is 3 months later than the accounts deadline. Not every dormant company needs a CT600 — see our guide on whether you need to file one.
First-year deadlines
First-year deadlines are slightly different. The Companies House deadline for first accounts is the later of:
- 9 months after the end of the first accounting period, or
- 21 months from the date of incorporation
This gives newly incorporated companies extra time. We cover this in more detail in our guide on first year filing for a new company.
Example: Company incorporated 1 December 2025. ARD = 31 December. First accounting period runs to 31 December 2026. Accounts deadline = later of 30 September 2027 (9 months) or 1 September 2027 (21 months from incorporation). In this case, 30 September 2027.
The first CT600 follows the standard 12-month rule from the end of the accounting period.
Confirmation statement
Separately from accounts, every company must file a confirmation statement (CS01) with Companies House at least once every 12 months from the date of incorporation (or the last confirmation statement). The filing fee is £34 online or £62 paper. This is not the same as annual accounts — it is a separate requirement.
Calendar summary
| Filing | Deadline | Where |
|---|---|---|
| Annual accounts | 9 months after accounting period end | Companies House |
| CT600 | 12 months after accounting period end | HMRC |
| Confirmation statement | Every 12 months from incorporation/last CS01 | Companies House |
How to avoid missing deadlines
- We calculate your deadlines automatically in DormantFile and send email reminders at 90, 30, 14, 7, 3, and 1 day before they are due.
- You can also check your deadlines on the Companies House company page by searching for your company.
- File early — there is no penalty for filing before the deadline, and both filings can be submitted well in advance.
Key points
- Accounts: 9 months after accounting period end (21 months from incorporation for first accounts).
- CT600: 12 months after accounting period end.
- Confirmation statement: every 12 months, £34 online / £62 paper, separate from accounts.
- Late filing triggers automatic penalties from both Companies House and HMRC. If you're already late, the penalty calculator shows what you owe.