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HMRC internal manual

Company Taxation Manual

CTSA: the filing obligation: prescribed form of CT600

A return must include a properly completed form CT600 or an approved substitute version of it. A non-approved format is unacceptable.

Head Office must approve substitute versions (see CTM93160).

COTAX does not send out the CT600 return form or guidance notes to companies:

  • with an agent acting,


  • that the COTAX record shows use an approved substitute form.

COTAX does not issue supplementary pages in any case.

Companies and agents who need the official form or relevant supplementary pages can obtain them from the CTSA order line, Tel. 0845 300 6555, Fax. 0845 300 6777 (calls charged at local rates).

Tax Offices can order small supplies of forms CT600, CT600 Guide, and CT600 Supplementary Pages. Copies ordered will be for the use of Tax Office staff and only an occasional urgent request from the public.

The form CT600 is recognisably a development of the form CT200 used for CTPF accounting periods.

It contains eight sections and there are also supplementary return pages that certain companies need to complete.

  • Section 1 of the form CT600 includes a declaration by the person making the return to the effect that the return is to the best of his or her knowledge correct and complete. The declaration must contain a signature. Who can sign a return on behalf of a company is at CTM93170.
  • Section 2 (turnover of the company). must be completed by every company with trading or professional income.
  • Section 3 contains a short calculation of tax payable (for the more straightforward case).
  • Section 4 a detailed calculation of tax payable.
  • Section 5 covers claims to capital allowances.
  • Section 6 losses, deficits and other excess amounts.
  • Section 7 is for repayment claims.
  • Section 8 is an optional section for showing an analysis of directors’ remuneration.

There are nine different supplementary return pages. Companies need to obtain and complete supplementary pages if they:

CT600A Are close and have made loans or advances during the return period to participators or associates of participators, who did not repay those loans or advances during the return period
CT600B Are claiming or surrendering any amounts under the group or consortium relief provisions
CT600C Have an interest of 25% or more in a foreign company (controlled foreign company)
CT600D Are an insurance company
CT600E Are a registered charity
CT600F Operate ships and are party to a Tonnage Tax election
CT600G Make claims after 1 April 200 but before 1 April 2010 under the Corporate Venturing Scheme
CT600H Receive cross-border royalties
CT600I Pay supplementary tax on ring fenced profits