Home Capital allowances Maximum AIA calculations for split accounting periods

Maximum AIA calculations for split accounting periods

Maximum AIA calculations for split accounting periods

The recent, and temporary, increase in the AIA to £1m from 1 January 2019 creates computational issues if a trader’s accounting period straddles this date.


The following example published by HMRC illustrates one variant that you may encounter when considering AIA relief due to clients.


Where a business has a chargeable period from 1 July 2018 to 30 June 2019, the maximum AIA for this period would be £600,000 calculated as follows:


a) the proportion of the period from 1 July 2018 to 31 December 2018, that is, 6/12 x £200,000 = £100,000 and


b) the proportion of the period from 1 January 2019 to 30 June 2019, that is 6/12 x £1,000,000 = £500,000


£100,000 + £500,000 = £600,000.


However, in relation to (a), the part period falling before 1 January 2019, no more than a maximum of £200,000 of the company’s actual expenditure in that particular part period would be covered by its transitional AIA entitlement (the maximum claimable before the increase on 1 January 2019).