CA11120 | General: claims: how to claim
From HM Revenue & Customs · Capital Allowances Manual
Capital allowances must be claimed. If there is no claim there are no capital allowances. Most capital allowances are claimed in the tax return. The claims legislation in TMA70/S42 (Income Tax) and FA98/SCH18/PARA54 - PARA60 (Corporation Tax) does not apply to capital allowances claimed in a return.
The claims legislation in TMA70/S42 (Income Tax) and FA98/SCH18/PARA54 - PARA60 (Corporation Tax) applies to
A capital allowance claim does not need to be for the full amount of the allowance. But the amount claimed must be specified.