Dormant for Companies House vs dormant for Corporation Tax

By Max Szolcek, founder of Dormant Return. Last updated 21 August 2026

"Dormant" is one word doing two jobs. Companies House and HMRC are separate regulators, each with its own definition of a dormant company and its own filings. A company can be dormant for one and not the other, and satisfying one never satisfies the other. Most confusion about dormant companies traces back to this split.

The two definitions

Companies House: no significant accounting transactions

For Companies House, a company is dormant if it has had no significant accounting transactions during the financial year. Helpfully, three things are explicitly ignored: filing fees paid to Companies House, penalties for late filing of accounts, and money paid for shares when the company was incorporated. A company that has only ever done those things can still file dormant accounts.

HMRC: not trading and no income

For Corporation Tax, a company is usually dormant when it has stopped trading and has no other income, or is a new company that has not started trading. HMRC's idea of trading is broad: buying, selling, renting property, advertising, employing someone or earning interest all count. Bank interest of a few pence is enough to make a company active for Corporation Tax while still dormant for Companies House.

The two sets of filings

The most important row is the second. Dormancy never removes the Companies House obligations: accounts and a confirmation statement are due every year for as long as the company exists. The HMRC side, by contrast, can genuinely go quiet: once HMRC agrees a company is dormant it normally stops issuing notices, and with no notice there is no return to file. The mechanics are in do dormant companies need to file a CT600? and how to tell HMRC your company is dormant.

The traps between the two

• Assuming Companies House dormant accounts cover HMRC. They do not. If HMRC expects a CT600, filing dormant accounts at Companies House does nothing to answer it, and late filing penalties accrue even though no tax is due.
• Assuming the definitions match. A company holding cash that earns interest can be dormant at Companies House and active for Corporation Tax at the same time. The regulators do not reconcile their views; you have to satisfy each separately.
• Assuming one regulator tells the other. They exchange some data (a new company is registered with HMRC automatically), but telling HMRC the company is dormant does not update Companies House, and vice versa.
• Different periods. The Companies House financial year and HMRC's Corporation Tax accounting period usually line up, but not always, particularly in the company's first year. The return must use the period HMRC expects.

Related guides

• Is my company dormant? A five-question check
• Dormant company with money in the bank
• Bank interest and dormant companies
• Do dormant companies need to file a CT600?
• How to tell HMRC your company is dormant
• Dormant company iXBRL accounts explained

Sources

• GOV.UK: Dormant for Companies House
• GOV.UK: Dormant for Corporation Tax