Whether a dormant company has to file a Company Tax Return, when HMRC will and will not ask for one, and how it differs from your accounts.
A genuinely dormant company does not pay Corporation Tax, and in most cases does not have to file a CT600 Company Tax Return either. The detail matters though, because whether you file depends on what HMRC has asked for. This guide explains when a dormant company must file a return and when it does not.
If the company is dormant and HMRC knows
If you have told HMRC the company is dormant for Corporation Tax and HMRC has accepted that, you normally do not have to file a Company Tax Return. HMRC simply does not expect one while the company is not trading. There is no tax to pay because there is no taxable profit.
If HMRC has issued a notice to deliver a return
This is the trap. If HMRC has sent a notice to deliver a Company Tax Return, that notice stands until it is dealt with, even if the company turns out to be dormant. In that case you either file a CT600 showing no activity, or contact HMRC to have the notice withdrawn because the company is dormant. Ignoring the notice can trigger penalties.
The CT600 is separate from your accounts
It is easy to confuse the two filings. The Company Tax Return, the CT600, goes to HMRC. The dormant company accounts go to Companies House. They have different deadlines and different rules. A dormant company that owes no Corporation Tax return to HMRC still has to file dormant accounts and a confirmation statement at Companies House every year.
Dormant with a little bit of income
If the company has any taxable income, for example bank interest, it may not count as dormant for Corporation Tax even if it looks quiet. In that case HMRC will expect a return. If you are unsure whether small amounts of interest change your position, check with HMRC before assuming the company is dormant.
The 2028 filing change
From April 2028 all Companies House accounts, including dormant accounts, move to software-only filing. The CT600 side already goes through software or HMRC online. If you run a dormant company, the practical change in 2028 is on the Companies House accounts, and we are building a free tool to handle exactly that.