Hi,
Effectively any such grant, with a few exceptions, reduces the qualifying expenditure accordingly. This normally relates to grants received on the purchase of an asset or shortly after, although there is not any specific time limit for receiving the grant that relates to this. The grant is not towards the purchase cost however, it is to scrap the asset and so we think the more relevant instruction here would be at CA23240 which covers disposal events and more specifically CA23250 that gives a list of what disposal amounts need to be brought into account.
CA23240 - PMA: WDA & balancing adjustments: Disposal events
CA23250 - PMA: WDA & balancing adjustments: Disposal values
For 'demolition or destruction' of the asset it says 'net amount received for the asset together with any insurance money received for the demolition or destruction and any other capital compensation. This would seem to cover any payment made for scrappage and so it should be brought in as the disposal value, assuming that was all that was received, in respect of the asset.
Thank you.