How to File a CT600 for a Dormant Company
Your company hasn't traded. No income, no expenses, no activity. But you still need to file a CT600 — and you can be fined if you don't.
Do Dormant Companies Really Need to File?
Yes. If HMRC has issued a CT603 (notice to deliver a Company Tax Return), you must file — even if the return shows all zeros.
The only exception: if you've told HMRC your company is dormant AND they've confirmed they won't issue CT603 notices. But most directors never do this, so you still get the notice.
What Goes on a Dormant CT600?
A dormant CT600 is straightforward:
- Box 1: Company name
- Box 2: Company registration number
- Box 3: Tax reference (UTR)
- Box 4: Company type (usually 00)
- Boxes 30-35: Accounting period dates
- Box 63: Tick "company is dormant"
- Box 145: Turnover = £0
- Box 315: Total profits = £0
- Box 525: Tax payable = £0
- Box 80: Declaration
Everything else: zero or blank.
How to File with Taxpipe
Taxpipe auto-detects dormant companies and takes a shortcut:
- Sign up at taxpipe.co.uk/signup
- Enter your company number — we fetch your details from Companies House
- Select "Dormant" in the wizard — all boxes auto-zero
- Review — takes 30 seconds
- Pay £59 and submit
Your return is filed directly to HMRC. You'll get a confirmation with a correlation ID.
What About Accounts?
Dormant companies also need to file accounts at Companies House, but these are even simpler. You can file dormant accounts for free at Companies House. This is separate from the CT600.
What If My Company Has a Bank Account?
Having a bank account doesn't automatically make your company non-dormant. A company is dormant if it has had no significant accounting transactions during the period.
Significant transactions include:
- Any trading income or expenses
- Paying dividends
- Buying/selling assets
- Receiving interest (other than a tiny amount on the bank account)
Transactions that DON'T count:
- Filing fees paid to Companies House
- Late filing penalties
- Bank interest under a few pounds (practice varies)
Can I Make My Company Dormant?
If your company has stopped trading:
- File final accounts at Companies House
- File final CT600 covering the trading period
- Write to HMRC saying the company is now dormant
- HMRC should stop issuing CT603 notices
If you plan to trade again in future, keep the company dormant rather than dissolving it.
What If I'm Late?
Same penalties as any other CT600:
- £100 at 1 day late
- £200 at 3 months
- More at 6 and 12 months
It doesn't matter that the tax bill is £0 — the penalties are for late FILING, not late payment.
Taxpipe — Dormant company? File in 5 minutes. £59.