Business Tax- R&D claim with additional information- Box 650/657
Article ID
business-tax-rd-claim-with-additional-information-box-650-657
Article Name
Business Tax- R&D claim with additional information- Box 650/657
Created Date
27th March 2026
Problem
Resolution
You have ticked the R&D ‘additional information box’ and made a R&D claim (either intensive or RDEC) but when you run the CT600 the boxes 650 and 657 are not ticked.
Please update to IRIS version 26.1.0 first and check again – if the boxes are still empty try this refresh: Go into ‘Enhanced Expenditure data entry’ screen and change the company size to large, close the screen. Then run a Tax computation. Go back to the ‘Enhanced Expenditure data entry’ and change back to small or medium and run the Tax comp and now run the CT600.
If you are making a claim for RDEC specifically (and not R&D intensive relief) then Box 650 will be blank. This has been logged as a issue with our Development team and will be resolved for the planned a Service pack to 26.1 to be released after April 2026 (date TBC). Our apologies for the inconvenience. If you need to submit asap then add a note using edit/notes and add to state the 2 boxes are meant to be filled in.
If you get a error when submitting then remove the tick for additional information (add a note to explain 650/657 should be ticked)- and regenerate and submit. This is being fixed by the 26.1 Service pack release (after april) OR there is a HMRC schema update planned for 6 April 2026 – when that date arrives then regenerate and submit.
What you want these ticked but the 2 boxes are empty:
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