A comparison of the Annual Investment Allowance and full expensing / 50%
first-year allowance
Kevin Smith

The Annual Investment Allowance and full expensing (including the 50% first-year allowance) both provide substantial tax relief in the period of expenditure. Each can be claimed in the same period, depending on the amount of expenditure and the plant or machinery category.
Because of this, they are synonymous with each other and are often discussed and considered interchangeably. This close relationship can conceivably lead to inadvertent overlapping and misunderstanding.
Here, we set out where each is mutually different and similar, including some undeniable trivia.
Differences
Annual Investment Allowance | Full expensing / 50% first-year allowance |
Introduced in 2008 | Introduced in 2023 (50% fya in 2021) |
It is not a first-year allowance | It is a first-year allowance |
Available on acquiring either new or second-hand plant or machinery | Only available on acquiring new plant or machinery |
Available to individuals, companies and most partnerships | Only available to companies chargeable to UK corporation tax |
Not available to mixed partnerships | Available to the corporate members of a partnership |
Time apportioned for periods that are shorter or longer than 12 months | Not time apportioned |
Limited to £1 million per period | No limit on expenditure |
The £1 million limit is applied as a whole to a group of companies or to all entities under common control | Available to each individual company, irrespective of being part of a group or being under common control |
Available on plant and machinery assets acquired for leasing | Not available on plant and machinery acquired for leasing (except for background plant and machinery) |
Disposal value is recognised in the appropriate pool | Automatic balancing charge on disposal value for the asset claimed |
Similarities
Annual Investment Allowance and full expensing / 50% first-year allowance |
Must be claimed in the period the expenditure is incurred |
The plant or machinery must be owned in the period the expenditure is incurred, in order to claim |
A reduced amount can be claimed |
Not available on cars |
Mutually exclusive – both cannot be claimed on the same expenditure amount |
Not available on expenditure incurred in the final period |
Not available if the plant or machinery is acquired as a gift |
Pre-trading expenditure rules |
For the vast majority of companies incurring under £1 million annual expenditure on plant and machinery, the unequivocal decision is to claim the Annual Investment Allowance, rather than full expensing / 50% first-year allowance. This is of course because any special rate expenditure is 100% claimed in the first year, rather than 50% and also, in most cases, a balancing charge will not be suffered on disposal. A consequential advantage of claiming the Annual Investment Allowance, is the assets in question will not have to be individually tracked.
© Smith Kelland Limited
This is for general information purposes only. It is not advice and is not intended to be advice.

Kevin Smith
BSc MRICS MSc (Property Investment)
For 25 years, my capital allowances experience and knowledge has been, and continues to be, crafted and refined the one and only way – by always working and flourishing at the ‘coalface’. Actually doing the work – the research, detailed analysis, surveys, liaising, problem solving, decision making, referencing the legislation and deciphering its minute parts.
I thrive on working with and advising UK and overseas property investors, landlords and occupiers. Assisting each to achieve their full capital allowances entitlement under the legislation. I am fortunate to advise and work on a significant number of construction projects and property transactions of varying values and complexity.