Filing dormant accounts with Companies House does not settle things with HMRC. This article covers the Corporation Tax side: when no return is needed, when a nil return is, and what to do when the company was dormant for only part of the year.
Dormant for Corporation Tax
HMRC treats a company as dormant when it is not active for Corporation Tax purposes: it is not trading, has no income and is not managing investments. A new company that has not started yet, and a company that has stopped for good or for now, both qualify.
HMRC has to be told. Until it accepts that the company is dormant, it goes on sending a notice to deliver a Company Tax Return each year, and each notice must be answered with a return. See Dormant for Corporation Tax on gov.uk for how to tell HMRC.
Which applies to you
| Situation | What to do in Tax Optimiser |
|---|---|
| HMRC has accepted the company is dormant and has not sent a notice | Mark Corporation Tax as not required |
| HMRC has sent a notice to deliver, and the company was dormant all period | File a nil return |
| The company was active for part of the period | File a return for the active part |
No return needed: mark Corporation Tax as not required
Every accounting period starts with both filings expected. Open the period Overview and find the Corporation Tax return steps in the Setup Process Checklist.
Choose Mark as not required beneath those steps and confirm. The section collapses to Not required, and the Corporation Tax and File CT600 with HMRC entries leave the menu. The accounts and the Companies House filing are untouched.
If HMRC later asks for a return for that period, choose Mark as required and everything comes back.
Only do this when no return is due. Marking it as not required does not tell HMRC anything. If a notice to deliver has been issued, a return must be filed or HMRC will charge a late filing penalty, even though no tax is owed.
A notice has arrived: file a nil return
A nil return is an ordinary CT600 on which every figure is nothing. Leave Corporation Tax as required, mark the period as dormant, and go through the Corporation Tax submission as usual. The accounts you prepared for Companies House are attached automatically.
Filing a nil CT600 for a company that has never traded shows every screen. The steps are identical for a company that used to trade and was dormant all period.
You will need the company’s UTR and Government Gateway details. The payment made for the dormant accounts covers the return for the same period, so you are not charged twice.
Dormant for part of the period
If the company traded for some of the accounting period, the accounts are normal micro-entity or small company accounts for the whole period. For Corporation Tax, though, the return can cover only the months the company was active, because a Corporation Tax accounting period ends when a company stops trading.
- On the period Overview, find CT Dates and choose Override.
- Enter the CT Start Date and CT End Date of the active part.
- Save. The Overview shows the new dates, and the computation and CT600 use them. The accounts keep the full period.
In this example the company traded until 31 March 2024, so the return covers 1 January to 31 March. Clear Override puts the dates back to the full period. The same control is on the General section of the computation as Override CT period.
Check the dates against HMRC’s notice. The period on the return has to match the period HMRC expects. If HMRC also wants a return for the dormant months, that is a separate, nil return.
When the company starts trading again
- Tell HMRC within three months of starting: Restarting a dormant company on gov.uk.
- In the period it restarts, untick Dormant company in Company Information and choose Mark as required for Corporation Tax.
- That period needs normal accounts and a normal return.
Frequently asked questions
I filed dormant accounts at Companies House. Does HMRC know?
No. Companies House and HMRC are told separately. Tell HMRC the company is dormant through its online services or by post.
Is there a penalty for not filing a nil return?
Yes, if HMRC issued a notice to deliver. Late filing penalties apply to a return even when no tax is due.
Does marking Corporation Tax as not required delete my computation?
No. It hides the Corporation Tax screens for that period. Mark as required brings them back with whatever was there.
Do I pay again to file the CT600 after filing dormant accounts?
No. One payment, or one credit for a firm, covers both filings for the period.
My company received bank interest. Can I still use the dormant route?
No. Interest is income, so the company is active for Corporation Tax and not dormant for Companies House for that year. File normal accounts and a normal return.