CA14300 | General: Contributions: Contributions that are repaid
From HM Revenue & Customs · Capital Allowances Manual
Extra Statutory Concession B49 (ESC/B49)
Sometimes the recipient of a grant may repay all or a part of it. Where they do there is nothing in the legislation that lets them claim capital allowances on their true net expenditure. ESC/B49, which was withdrawn from 1 April 2013 for the purposes of Corporation Tax and 6 April 2013 for the purposes of Income Tax, allowed a person who had repaid all or part of a grant that had been deducted from expenditure qualifying for capital allowances to claim capital allowances on the amount repaid if:
the grant was made by the Crown, any Government or any other public or local authority, or
the repaid grant is taxable in the hands of the person who made the grant as a balancing adjustment or a revenue receipt.
These were the only cases where a person repaying all or part of a grant could have been given capital allowances on the amount repaid. Since ESC/B49 has been withdrawn you should refuse to give capital allowances in all cases on a grant repaid because there is nothing in the legislation to allow them.