Filing Annual Accounts at Companies House: Complete Guide
Every UK limited company must file annual accounts at Companies House. This is separate from your CT600 corporation tax return (filed with HMRC), though the two are closely related.
This guide covers everything you need to know about Companies House annual accounts.
Two Filings, Two Deadlines
| Filing | To | Deadline |
|---|---|---|
| Annual accounts | Companies House | 9 months after year end |
| CT600 tax return | HMRC | 12 months after year end |
| Corporation tax payment | HMRC | 9 months + 1 day after year end |
For a year ending 31 March 2025:
- CH accounts due: 31 December 2025
- Tax payment due: 1 January 2026
- CT600 due: 31 March 2026
The Companies House deadline is the earliest. Many directors miss it because they focus on the HMRC deadline.
First Year Exception
In your first year, you get 21 months from incorporation to file accounts. After that, it's always 9 months.
What Goes in Your Accounts?
Your annual accounts must include:
- Balance sheet — what the company owns and owes at the year end
- Profit and loss account (unless dormant/micro-entity exemption)
- Notes to the accounts — accounting policies, additional details
- Director's report (unless small company exemption)
The level of detail depends on your company size.
Company Size Categories
Micro-Entity (simplest)
At least 2 of:
- Turnover ≤ £632,000
- Balance sheet total ≤ £316,000
- ≤ 10 employees
What you file: Simplified balance sheet only. No profit and loss account. No director's report. Minimal notes.
Small Company
At least 2 of:
- Turnover ≤ £10.2 million
- Balance sheet total ≤ £5.1 million
- ≤ 50 employees
What you file: Abbreviated accounts (abridged balance sheet, simple P&L, basic notes). No audit required.
Medium and Large Companies
Full accounts with audit. Most companies reading this guide won't fall into these categories.
Filing Format: iXBRL
Since 2011, Companies House accounts must be filed electronically in iXBRL (inline eXtensible Business Reporting Language) format. This means:
- Your accounts are both human-readable (HTML) and machine-readable (XBRL tags)
- Each number is "tagged" with a standardised code
- Companies House systems can automatically process and validate the data
Taxonomy Standards
- FRS 102 Section 1A — for small companies (most common)
- FRS 105 — for micro-entities (simplest)
- Full FRS 102 — for medium/large companies
Your filing software handles the iXBRL formatting automatically.
How to File
Option 1: Companies House WebFiling (Free)
Log into Companies House WebFiling and use their online forms. Suitable for micro-entities with very simple accounts.
Option 2: Filing Software
Software like Taxpipe generates iXBRL-compliant accounts and can file them directly. Better for companies with more complex accounts.
Option 3: Accountant
Your accountant prepares and files accounts on your behalf. The most expensive option but provides professional assurance.
Late Filing Penalties
Companies House penalties are automatic and non-negotiable:
| How Late | Private Company | Public Company |
|---|---|---|
| Up to 1 month | £150 | £750 |
| 1–3 months | £375 | £1,500 |
| 3–6 months | £750 | £3,000 |
| Over 6 months | £1,500 | £7,500 |
Doubled if you file late two years in a row.
There is no appeal against these penalties unless there are exceptional circumstances (serious illness, natural disaster). "I forgot" or "my accountant was late" does not qualify.
Dormant Companies
If your company is dormant (no significant accounting transactions), you can file dormant company accounts. These are very simple — essentially just a balance sheet showing the company has no assets or liabilities beyond the initial share capital.
Dormant accounts can be filed through Companies House WebFiling for free.
Linking Accounts to Your CT600
When you file your CT600 with HMRC, you must include iXBRL accounts as an attachment. These should be consistent with (but not necessarily identical to) the accounts you file at Companies House.
Key differences:
- Companies House: Files abbreviated/abridged accounts (less detail for public record)
- HMRC: Receives full accounts (including profit and loss) for tax purposes
The underlying data should be the same — only the level of disclosure differs.
Common Mistakes
1. Filing Accounts Late at CH but On Time at HMRC
The CH deadline (9 months) is 3 months earlier than HMRC (12 months). Don't confuse them.
2. Inconsistent Figures
If your CH accounts show different numbers from your CT600, expect questions from both bodies.
3. Wrong Accounting Standards
Using FRS 102 when you qualify for FRS 105 (or vice versa) can cause rejection. Check your company size category.
4. Missing Balance Sheet Signature
The balance sheet must be approved by a director. Electronic filing requires the director's name (not a physical signature).
Key Takeaways
- File accounts at CH within 9 months of your year end
- Choose the right size category — micro-entity is simplest for small companies
- iXBRL format is mandatory — use filing software or an accountant
- Penalties are automatic and there's effectively no appeal
- Keep figures consistent between CH accounts and HMRC CT600
Coming Soon: File Accounts Through Taxpipe
We're building Companies House accounts filing into Taxpipe. File your CT600 and annual accounts from one platform — no duplicate data entry.
File your CT600 now → — £59, with iXBRL accounts included for HMRC.