IAS 20793 Personal Tax- 2025 Capital gains % rate incorrect and Adjustment in Box 51 CG3 (Fixed 25.3)
Article ID
personal-tax-2025-capital-gains-adjustment-value-incorrect-in-box-51-cg3
Article Name
IAS 20793 Personal Tax- 2025 Capital gains % rate incorrect and Adjustment in Box 51 CG3 (Fixed 25.3)
Created Date
10th July 2025
Problem
Resolution
Personal tax Capital Gains Rate incorrect ‘Adjustment’ value (Box 51 in CG3 page) because of the incorrect basic rate band allocation and is a DEFECT (affects version 25.1.4). The basic rate band is allocated against the capital gains incorrectly and increasing the capital gains tax liability which results in a large capital gains tax adjustment in Box 51. However, the overall capital gains liability is correct.
The Example below to explain the incorrect and correct calculation:-
Expected result
Tax on 37,700 @ 10%
Tax on 334,150 @ 20%
Tax on 3,154 @ 24%
TAX DUE = £71,356.96
Box 51 (Adjustment) = 126
Actual result
Tax on 34,456 @ 10%
Tax on 3,154 @ 18%
Tax on 337,304 @ 20%
TAX DUE = £71,483.12
Box 51 (Adjustment) = 252
The IRIS Development Team confirmed a fix to this is now out. Update to IRIS version 25.3 released in early October 2025.
If you still disagree with the 25.3 CG calculation then do apply this workaround to edit the final CG tax calc (the % rates cannot be edited)- by going to Edit | Capital Assets | Edit | Losses & Other Information and adding a manual adjustment under the ‘CG tax adjustment’ field to correct the CG calculation (to reduce it then use a minus value etc), and then entering a note into the additional information space. Our Development team is looking for a future update after version 25.3 and we are awaiting news of a release date- we recommend you do not wait and to use the workaround as stated above.
We sincerely apologise for the inconvenience.
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