CTM93140 - 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.

HMRC, Substitute Forms Approval (CDIO) must approve substitute versions, see CTM93160.

Companies and agents who need the official form or relevant supplementary pages can obtain them from the GOV.UK website.

The form CT600 contains specific sections and there are also supplementary return pages that certain companies may need to complete.

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

Page number	Page content
CT600A	Are close and have made loans or advance arrangements to confer benefits during the return period to participators or associates of participators, who did not repay thoses loans or advances during the return period
CT600B	Held an interest of 25% in a foreign company controlled from the UK at any time in the accounting period.
CT600C	Are claiming or surrendering relief under the group or consortium relief provisions
CT600D	Are involved in Overseas Life Assurance Business
CT600E	Are a charity or Community Amateur Sports Club (CASC) that claims exemption from tax on all or any part of its income and gains
CT600F	Operate ships and are party to a Tonnage Tax election
CT600H	Make cross-border royalty payments
CT600I	Carry on a ring fence trade (usually oil extraction or exploitation of rights in the UK or UK Continental Shelf)
CT600J	Are party to any notifiable arrangements under FA2004/S308-310 set up to avoid tax
CT600K	Are chargeable to CT on restitution interest
CT600L	Are claiming Research & Development Expenditure Credit or R&D SME Payable Tax Credit
CT600M	Are claiming certain allowances relating to a Freeport tax site