Company Tax Return (CT600)
Use this form to file your Company Tax Return by post if you cannot file it online, or if you want to amend a return you've already submitted.
Documents
Details
You should use commercial software to file annual accounts and Company Tax Returns with HMRC.
You can only use this form to amend a return you’ve already submitted or to file a paper Company Tax Return if you:
- have a reasonable excuse
- are filing in Welsh
After you’ve completed the return, send it to:
Corporation Tax Services
HMRC
BX9 1AX
You’ll need to submit a WT1 form with your completed paper return if you’ve been unable to send your return online because of an IT problem with HMRC online services.
Find out about:
- completing your Company Tax Return
- Corporation Tax forms you need — along with associated guides, notes and supplementary pages
- accounts and tax returns for private limited companies
This form has been updated in readiness for when a Northern Ireland Executive together with the UK government decide to introduce a devolved rate.
See Northern Ireland Corporation Tax regime: draft guidance for more information.
Do not make entries in any of the Northern Ireland boxes until a Northern Ireland rate has been introduced.
Supplementary pages
Corporation Tax: close company loans and arrangements to confer benefits on participators (CT600A)
Corporation Tax: group and consortium relief (CT600C)
Corporation Tax: insurance (CT600D)
Corporation Tax: charity and Community Amateur Sports Clubs (CT600E)
Corporation Tax: Tonnage Tax (CT600F)
Corporation Tax: cross-border royalties (CT600H)
Corporation Tax: supplementary charge in respect of ring fence trades (CT600I)
Corporation Tax: disclosure of tax avoidance schemes (CT600J)
Corporation Tax: Restitution Tax (CT600K)
Corporation Tax: research and development (CT600L)
Corporation Tax: Freeports and Investment Zones (CT600M)
Corporation Tax: Residential Property Developer Tax (CT600N)
Corporation Tax: creative industries (CT600P)
Related forms and guidance
Use the Autumn Budget 2024 — overview of tax legislation and rates (OOTLAR) for an overview of the main Budget changes affecting Corporation Tax.
Use form 64-8: authorise your agent to authorise HMRC to communicate with an accountant, tax agent or adviser acting on your behalf.
Updates to this page
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Information about when you can use this form has been updated and English and Welsh versions of 'Company Tax Return CT600 (2026) Version 3' have been added.
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English and Welsh versions of Corporation Tax for Company Tax Return (CT600 (2025) Version 3) have been added.
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English and Welsh versions of Corporation Tax for Company Tax Return (CT600 (2024) Version 3) have been added.
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English and Welsh versions of Corporation Tax: Company Tax Return (CT600 (2023) Version 3) have been added.
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Added translation
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Corporation Tax: research and development (CT600L (2022) version 3) has been added.
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Corporation Tax: research and development (CT600L (2021) version 3) has been added.
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The Corporation Tax for Company Tax Return (CT600 (2021) Version 3) has been added.
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English and Welsh versions of the Corporation Tax for Company Tax Return (CT600 (2020) Version 3) have been updated.
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Welsh version of Corporation Tax for Company Tax Return (CT600 (2019) Version 3) has been updated.
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English and Welsh versions of Corporation Tax: Company Tax Return (CT600 (2019) Version 3) have been added.
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Corporation Tax: Company Tax Return (CT600 (2018) Version 3) has been added.
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English version of the October 2017 Company Tax Return (CT600 version 3) has been added.
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The Company Tax Return (CT600 version 3) has been updated to incorporate the reform of Corporation Tax loss relief.
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New version Corporation Tax: Company Tax Return (CT600 (2017) Version 3) has been added.
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First published.