A short life asset election keeps a piece of plant or machinery in its own single asset pool instead of the main pool, so that if it is sold or scrapped within about eight years the unrelieved cost is written off at once as a balancing allowance. Without the election, the sale proceeds are simply deducted from the main pool and the rest of the cost keeps trickling out at the main writing down rate, which is 14% for chargeable periods beginning on or after 1 April 2026 (companies) or 6 April 2026 (income tax).

What does a short life asset election actually do?

Sections 83 to 89 of the Capital Allowances Act 2001 (CAA 2001) contain the rules. An asset is a short life asset only if the person who incurred the qualifying expenditure elects to treat it as one and it is not excluded by section 84. HMRC’s Capital Allowances Manual at CA23620 is explicit that the actual or expected life of the asset is irrelevant. There is no test of whether the asset really will wear out quickly; what counts is a valid election for an asset that is not on the excluded list.

Once the election is made, section 86 requires the expenditure to go into a single asset pool, a “short life asset pool”, that holds nothing else. Writing down allowances on that pool are given at the main rate, so year by year the asset is relieved at the same pace as it would be in the main pool. The difference comes at the end:

  • For the main pool, the final chargeable period, which is the only period in which a balancing allowance can arise, is the period in which the qualifying activity permanently stops (section 65(1)).
  • For a single asset pool, the final chargeable period is the first period in which a disposal event occurs (section 65(2)).

Under section 55, if the pool balance in that final period exceeds the disposal value, the difference is a balancing allowance. If the disposal value is higher, there is a balancing charge instead. The election therefore accelerates relief when an asset is sold or scrapped for less than its tax written down value, and brings forward a charge when it is sold for more.

Which assets cannot be treated as short life assets?

CA23620 lists the exclusions in section 84. The main ones are:

  • cars, apart from hire cars provided wholly or mainly for disabled persons as defined in section 268D;
  • special rate expenditure, which includes integral features, long life assets, thermal insulation and cars with higher emissions;
  • assets used partly for purposes other than the qualifying activity, such as a sole trader’s laptop with some private use;
  • assets received as a gift, and assets that were first provided for some other purpose before being brought into the business;
  • ships, assets provided for special leasing, and assets that receive a partial depreciation subsidy;
  • assets provided for leasing, unless they will be used for a qualifying purpose throughout the designated period (section 87, CA23650).

GOV.UK summarises the practical position for most businesses: you cannot include cars, items you also use outside the business or special rate items. That leaves ordinary main rate plant such as computers, tools, catering equipment and machinery likely to be replaced within a few years.

How and when do you make the election?

Section 85 sets the procedure. The election must be made by notice to HMRC and must specify the asset, the qualifying expenditure incurred on it, and the date the expenditure was incurred. The time limits are:

Taxpayer Deadline
Company (corporation tax) No later than two years after the end of the chargeable period in which the expenditure was incurred
Sole trader or partnership (income tax) On or before the normal time limit for amending the tax return for the tax year in which that chargeable period ends

HMRC’s example at CA23640 shows how the income tax deadline works: a trader who buys a computer in the period ended 31 July 2012 must elect by 31 January 2015. If the expenditure is incurred in instalments across two periods, the deadline runs from the period of the first instalment. GOV.UK notes that a company tells HMRC on its Company Tax Return, while a sole trader or partnership tells HMRC in writing, giving the cost and the acquisition date. The election is irrevocable (section 85(4)).

Strictly each asset needs its own election and its own pool. CA23640 accepts that this is impracticable where assets are bought in large numbers, so HMRC will accept an election that identifies assets by batches of acquisitions with an aggregated cost, provided none of the assets is excluded and it is clear what is covered.

What happens if the asset is still owned after eight years?

Nothing is lost. Under section 86(2) and (3), if no final chargeable period has occurred by the eighth anniversary of the end of the chargeable period in which the expenditure was incurred, the short life asset pool ends and the remaining balance is moved into the main pool for the first chargeable period ending after that cut off. The asset then stops being a short life asset. A four year cut off applied to expenditure incurred before 1 April 2011 (corporation tax) or 6 April 2011 (income tax).

Is the election still worth making when other allowances cover the cost?

Often not. The election only helps where some cost is left in a pool. If the whole cost is relieved immediately, there is no balance for a later balancing allowance to release. The main immediate allowances are:

  • the annual investment allowance, which is £1 million for a 12 month period and covers most plant and machinery other than cars;
  • full expensing, available only to companies, on new and unused main rate plant bought from 1 April 2023, excluding cars;
  • the 40% first year allowance on new and unused main rate plant bought on or after 1 January 2026, excluding cars, which leaves 60% to be relieved through writing down allowances.

The election therefore earns its place where spending exceeds the annual investment allowance, or where a company buys second hand plant after using its allowance (second hand assets do not qualify for full expensing or the 40% allowance). HMRC’s own example at CA23640, a restaurant buying glassware, assumes the business has already used its annual investment allowance on other spending.

How does the arithmetic work?

Illustration only. A company with a 31 March year end has used its full annual investment allowance for the year to 31 March 2027. In May 2026 it buys a second hand printing press for £50,000 and makes a short life asset election. It sells the press in February 2029 for £8,000. Assuming the 14% main rate continues throughout:

Year to Short life asset pool Allowance
31 March 2027 £50,000 less WDA, leaving £43,000 £7,000
31 March 2028 £43,000 less WDA, leaving £36,980 £6,020
31 March 2029 £36,980 less £8,000 sale proceeds Balancing allowance £28,980

Without the election, the £8,000 would be deducted from the main pool and the remaining £28,980 would continue to be relieved at 14% on a reducing balance, giving about £4,057 in the year of sale and smaller amounts for many years after. The total relief is the same in the long run; the election brings it forward.

Can a short life asset be sold to a connected person?

Yes, but anti avoidance rules stop a business manufacturing a balancing allowance by selling cheaply. Under section 88, if a short life asset is sold for less than market value, the disposal value is market value unless the buyer is taxed on the benefit under the employment income rules or the connected person election below is made (CA23660).

Under section 89, on a disposal to a connected person an election can be made, by notice to HMRC within two years of the end of the chargeable period of the disposal, for the sale to be treated as taking place at the pool value. The buyer is then treated as incurring expenditure equal to that pool value and as having made the short life asset election at the same time as the seller, so the original eight year cut off carries over. No balancing allowance or charge arises on the transfer.

What are the common mistakes?

  • Electing for an excluded asset. Cars, integral features and anything with private use cannot be short life assets, however short their expected life.
  • Missing the deadline. There is no late election route in section 85, and once made the election cannot be withdrawn.
  • Expecting faster annual allowances. The pool attracts the same main rate as the main pool. The benefit only appears on disposal.
  • Electing where the full cost has already been relieved. If the capital allowances claimed already cover the full cost, the election adds nothing.
  • Losing track of the asset. Each pool needs its own computation and a record of when the asset is sold or scrapped. Scrapping with no proceeds is still a disposal event that triggers the balancing allowance.
  • Forgetting the cut off. At the eighth anniversary the balance must be moved into the main pool, not left in a separate pool indefinitely.

Short life asset treatment is separate from the accounting for disposals; see disposal of fixed assets for the book entries, and capital allowances on cars for why cars follow their own emissions based rules instead.

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Reviewed by Christine Anderson, Broker, Solar Protect. Last reviewed 8 October 2026. Part of Accountapedia, the Solar Protect guide to UK tax and accounting. This page is general information, not personalised advice.