Companies House vs HMRC: Understanding Both Filings
Every UK limited company must file with two separate government bodies: Companies House and HMRC. These are different organisations with different requirements. Here's what you need to know about each.
The Two Bodies Explained
Companies House
What it is: The registrar of companies in the UK
Purpose: Maintains the public register of companies
What you file: Annual accounts and confirmation statement
Who can see: Public (anyone can view your filed accounts)
HMRC (Her Majesty's Revenue & Customs)
What it is: The UK's tax authority
Purpose: Collects taxes and enforces tax law
What you file: CT600 corporation tax return
Who can see: Private (only HMRC and your company)
Key Differences
| Aspect | Companies House | HMRC |
|---|---|---|
| Purpose | Company registration | Tax collection |
| Main filing | Annual accounts | CT600 tax return |
| Deadline | 9 months after year-end | 12 months after year-end |
| Penalty start | £150 | £100 |
| Public/Private | Public record | Confidential |
| Format | iXBRL accounts | CT600 + iXBRL accounts |
What You File Where
Companies House Filings
Annual accounts containing:
- Balance sheet (Statement of Financial Position)
- Notes to the accounts
- Directors' report (if required)
- Auditor's report (if required)
- Confirms company details are correct
- Updates registered office, directors, shareholders
- Due within 14 days of anniversary
HMRC Filings
CT600 Corporation Tax Return containing:
- Company income and profits
- Allowable expenses
- Capital allowances
- Tax calculation
- Attached iXBRL accounts (same as CH but more detailed)
- VAT returns (if VAT registered)
- PAYE submissions (if you have employees)
- P11D benefits reporting
The Dual Filing Requirement
Why File to Both?
Companies House and HMRC serve different purposes:
- Companies House - Ensures transparency for stakeholders (customers, suppliers, investors)
- HMRC - Calculates and collects corporation tax
What's the Same?
- Company identification details
- Accounting period covered
- Balance sheet figures
What's Different?
| Element | Companies House | HMRC |
|---|---|---|
| Profit & Loss | Not required (micro-entity) | Required for CT600 |
| Tax calculation | Not included | Central to CT600 |
| Detail level | Can be abbreviated | Full disclosure needed |
| Computations | Not required | Tax computations attached |
Deadlines Compared
For a company with year-end 31 March 2025:
| Filing | Deadline | Days After Year-End |
|---|---|---|
| Companies House accounts | 31 December 2025 | 9 months |
| Corporation tax payment | 1 January 2026 | 9 months + 1 day |
| CT600 to HMRC | 31 March 2026 | 12 months |
Penalties Compared
Companies House Late Filing Penalties
| How Late | Penalty |
|---|---|
| Up to 1 month | £150 |
| 1-3 months | £375 |
| 3-6 months | £750 |
| Over 6 months | £1,500 |
HMRC Late Filing Penalties
| How Late | Penalty |
|---|---|
| 1 day late | £100 |
| 3 months late | Another £100 |
| 6 months late | 10% of unpaid tax |
| 12 months late | Another 10% of unpaid tax |
Filing Efficiently
Use One Software for Both
Good CT600 software files to both bodies:
- Enter your financial data once
- Generate iXBRL accounts
- Submit to Companies House
- Prepare CT600
- Submit to HMRC
What Order to File
Recommended sequence:
- Prepare accounts - Get your balance sheet right
- File to Companies House - Meet the earlier deadline
- Complete CT600 - Add tax-specific information
- File to HMRC - Submit corporation tax return
- Pay tax - Before the payment deadline
Common Confusions
"I filed with Companies House, am I done?"
No. Companies House filing is separate from HMRC. You still need to file your CT600.
"Why does HMRC want the same accounts?"
HMRC needs the accounts to verify your CT600 figures. They also need additional information not included in Companies House filings.
"Can I file different accounts to each?"
No. The core accounts must be consistent. HMRC accounts may include more detail, but the figures must match.
"Which deadline matters most?"
Both matter. Companies House penalties are immediate and fixed. HMRC penalties can escalate with unpaid tax.
Special Situations
Dormant Companies
| Body | Requirement |
|---|---|
| Companies House | Dormant accounts (simplified) |
| HMRC | CT600 showing nil activity |
First Year Filing
Your first accounting period can be longer than 12 months (up to 18 months for Companies House). You may need:
- One set of accounts covering the full period (CH)
- Two CT600s if period exceeds 12 months (HMRC)
Changing Year-End
If you change your accounting reference date:
- Notify Companies House
- File for the new period
- HMRC follows your new period automatically
Frequently Asked Questions
What if I miss both deadlines?
You'll face penalties from both bodies. Prioritise filing to stop penalties accumulating.
Do micro-entities file less?
Yes. Micro-entities can file:
- Abbreviated accounts to Companies House
- Full accounts with CT600 to HMRC (but still simpler than larger companies)
Can I file the CT600 before Companies House accounts?
Technically yes, but it's unusual and not recommended. HMRC expects accounts to be consistent with what's on public record.
What's the confirmation statement?
A separate Companies House filing confirming your company details. Due annually on your incorporation anniversary. Nothing to do with HMRC.
Do I need an accountant for both?
Many small companies file both themselves using software like TinyTax. Complex situations may benefit from professional help.
Summary
| Filing | Body | Deadline | Public? |
|---|---|---|---|
| Annual accounts | Companies House | 9 months | Yes |
| Confirmation statement | Companies House | 14 days from anniversary | Yes |
| CT600 | HMRC | 12 months | No |
| Corporation tax payment | HMRC | 9 months + 1 day | No |
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