IAS23590 Business Tax- R&D Box 653 is incorrectly ticked for CTAP start before 01/04/2025 but ended after 31/03/2023
Article ID
business-tax-rd-box-653-is-incorrectly-ticked-for-ctap-start-before-01-04-2025-but-ended-after-31-03-2023
Article Name
IAS23590 Business Tax- R&D Box 653 is incorrectly ticked for CTAP start before 01/04/2025 but ended after 31/03/2023
Created Date
23rd December 2025
Problem
Resolution
If you have updated to IRIS version 25.4.0.155 or have updated to the latest HOTFIXES in Dec 2025 but box 653 is still being ticked when it shouldn’t. This has been confirmed as a DEFECT which affects CTAPs that started before 01/04/2025 but ended after 31/03/2023 – where Box 653 is being completed incorrectly where R&D intensive checkbox in the data entry is not completed.
We plan to release a fix in the future IRIS version for April 2026.
If you need to submit a CT600 before April 2026 then please go to Edit and Notes and explain that Box 653 should not be ticked and submit as it is. Once we have updated the fix then you can submit an Amended return later on.
We apologise for any inconvenience.
We are sorry you did not find this KB article helpful. Please use the box below to let us know how we can improve it.