UK · complianceSources checked
When must a new UK company register for Corporation Tax?
HMRC states a company must tell it within 3 months of starting its tax accounting period if the company is active for Corporation Tax purposes. HMRC treats a company as active when it is, for example, carrying on a business or professional activity, buying and selling goods to make a profit, providing services, earning interest, managing investments, or receiving any other income.
Sources
- Corporation Tax: trading and non-tradinggov.uk (HM Revenue & Customs) · checked 17 August 2026
Related questions
- Does writing a business plan start the clock?
- No. HMRC states preliminary activities such as writing a business plan or negotiating contracts, and pre-trading expenditure, do not count as being active or trading for Corporation Tax purposes.
- What does HMRC treat as being active?
- HMRC gives examples including carrying on a business or professional activity, buying and selling goods with a view to profit, providing services, earning interest, managing investments, and receiving any other income.
What this answer does not cover
- This page covers when to tell HMRC the company is active. What a dormant company must do instead is a separate question, not covered here.
- HMRC updates its guidance from time to time, so confirm the deadline against the source before relying on it.
