CT600 Company Tax Return

What is a CT600 Company Tax Return?

CT600 Corporation tax form is used to report Company Tax Return. A company tax return is not just the company tax return form CT600 and any supplementary pages but also:

  • Accounts* for the period covered by the return and
  • Computations showing how entries on the return have been calculated from the figures in the accounts.

Any relevant claims, elections, reports, or statements must be included. Different information, accounts, statements and reports, may be required from different descriptions of a company as, for example, is the case with insurance** companies.

* 'Accounts' required are:

  • For companies resident in the UK throughout the period covered by the return and required by the law of the territory in which they are established or by EC Regulation 1602/2002 to prepare accounts covering that period, those accounts including a copy of any directors' and auditor's report similarly required. These are the accounts that a company is required to prepare under company law for its members and not the abbreviated accounts it may be permitted to file with the Registrar of Companies.
  • In the case of an insurance** company, a copy of the return deposited with the Financial Services Authority under Chapter 9 of the Prudential Sourcebook (Insurers) or Chapter 5 of the Prudential Sourcebook (Friendly Societies) for the period coinciding with or overlapping the period covered by the return.
  • For companies not resident in the UK but carrying on a trade through a permanent establishment (PE) in the UK:
    • The trading and profit and loss accounts of the company required by the law of the territory in which it is established or by EC Regulation 1602/2002
    • A profit and loss account of the UK PE covering the period to which the return relates drawn up in accordance with UK generally accepted accounting practice (GAAP) or international accounting standards (IAS)
    • Balance sheet for the company required by the law of the territory in which it is established or by EC Regulation 1602/2002 at the end of the period of account, and
    • If prepared, the balance sheet of the UK PE at the same date drawn up in accordance with UK GAAP or IAS
    • All accounts and balance sheets must be in English
  • In any other case, a copy of any accounts, including balance sheet, that the company is required by statute or by its constitution to prepare, covering the period to which the return relates.
  • Where the company was outside the charge to CT (for example, because it was dormant) and there is no single set of accounts that covers the period, you should enclose the most recent accounts prepared.

**Insurance company is a person who has permission under Part 4 of the Financial Services and Markets Act 2000 to effect or carry out contracts of insurance.

If you do not include all the relevant items you will not have satisfied the legal requirements to deliver a company tax return.


When you must deliver a Company Tax Return

A Company Tax Return has to be delivered at any time after the end of its Accounting Period but it must be submitted no later than the legal filing date, which is normally the later of:
• 12 months after the end of the Accounting Period or,
• three months after the company receives the Notice (form CT603).

Delivering your return online to HMRC

From 1 April 2011 onwards, all companies must deliver their Company Tax Return online for any accounting period ending after 31 March 2010. The computations and generally the accounts must be in Inline eXtensible Business Reporting Language (iXBRL). Andica CT600 Corporation Tax Software includes an in-built File By Internet feature.  

HMRC have provided following Company tax return guide to form CT600 (2022) Version 3 for accounting periods starting on or after 1 April 2015 to assist Companies complete the Corporation tax returns. Further information can also be found on GOV.UK website.