Corporation Tax technical specifications: CT600 appendices

Appendices for Corporation Tax Online software developers.


Appendix C: Annual Investment Allowance version 3.4

This file may not be suitable for users of assistive technology. Request an accessible format.

If you use assistive technology (such as a screen reader) and need a version of this document in a more accessible format, please email Please tell us what format you need. It will help us if you say what assistive technology you use.


Appendices for rates of tax, Marginal Rate Relief validation and Annual Investment Allowance.

Published 1 January 2014
Last updated 12 October 2015 + show all updates
  1. Appendix C of the Annual Investment Allowance has been updated with version 3.3.
  2. Appendix A: rates of tax version 2.5 has been published.
  3. Appendix A and Appendix B have been updated to include Corporation Tax rates/fractions from April 2015.
  4. Appendix C Annual Investment Allowance version 3.2 has been published.
  5. First published.