Tools and templates

Capital allowances calculator for companies

Enter a company's plant and machinery spending and its pool balances to see the capital allowances for one accounting period: the £1 million annual investment allowance, full expensing, the 50% and 40% first-year allowances, and writing-down allowances. The main pool rate falls from 18% to 14% for periods from 1 April 2026, with a hybrid rate across that date.

Last reviewed 28 October 2026

Key facts

Annual investment allowance	£1,000,000 a year, in proportion for a shorter period; one AIA shared by companies under common control
Full expensing	100% on new and unused main-rate plant and machinery bought on or after 1 April 2023, companies only, no end date; not cars, not for leasing
50% first-year allowance	New and unused special rate plant and machinery, companies only; the rest goes to the special rate pool
40% first-year allowance	New main-rate plant and machinery bought on or after 1 January 2026; leasing allowed; the rest goes to the main pool
Main pool writing-down allowance	18% before 1 April 2026; 14% for periods beginning on or after it; a hybrid rate for a period across the date
Special rate pool	6% a year
Small pools allowance	Write off a pool of £1,000 or less
Zero-emission cars and charge-points	100% first-year allowance to 31 March 2027 for companies

As at 25 October 2026.

Work out the allowances

First day of the accounting period Last day of the accounting period Main pool brought forward (£) Special rate pool brought forward (£) New and unused main-rate plant and machinery, not cars (full expensing) (£) New main-rate plant for leasing, bought on or after 1 January 2026 (40% first-year allowance) (£) Other main-rate plant and machinery, for example second-hand (£) New special rate plant: integral features, long-life assets, thermal insulation, solar panels (£) Cars with CO2 emissions up to 50 g/km (£) Cars with CO2 emissions above 50 g/km (£) New zero-emission cars and electric vehicle charge-points (£) Disposal proceeds of main pool assets (£) Disposal proceeds of special rate pool assets (£) Disposal proceeds of assets on which full expensing was claimed (£) Annual investment allowance allocated to this company, if shared in a group (£, leave empty for the full amount)

Enter the period and the expenditure and select Work out the allowances.

The main pool rate across 1 April 2026

For a chargeable period that straddles 1 April 2026, the main pool rate is a hybrid: (18 × days before 1 April 2026 + 14 × days on or after it) ÷ days in the period, rounded up to two decimal places (Finance Act 2026, section 28). Three examples:

Accounting period	Days before / from 1 April 2026	Main pool rate
1 January 2026 to 31 December 2026	90 / 275	14.99%
1 July 2025 to 30 June 2026	274 / 91	17.01%
1 October 2025 to 30 September 2026	182 / 183	16.00%

Worked example

A company with a year from 1 April 2026 to 31 March 2027 has a main pool of £50,000 brought forward. In the year it buys new machinery for £100,000, spends £20,000 on integral features and buys a car with emissions under 50 g/km for £15,000.

Item	Allowance
Annual investment allowance on the integral features	£20,000
Full expensing on the new machinery	£100,000
Writing-down allowance: (£50,000 + £15,000) × 14%	£9,100
Total allowances	£129,100
Main pool carried forward	£55,900

The calculator uses the annual investment allowance first on special rate expenditure, which would otherwise get 50% or 6%, then on main-rate expenditure that cannot be fully expensed. A company may allocate it differently in its return.

Where the allowances go on the CT600

Allowance	CT600 box (trading)
Annual investment allowance	690
Full expensing: allowance / balancing charge	688 / 689
50% special rate allowance / charge	693 / 694
Special rate pool: allowance / charge	695 / 700
Main pool: allowance / charge	705 / 710
40% first-year allowance	725 for now; qualifying expenditure in 760

HMRC has said that until its service update in April 2027 the 40% allowance goes in box 725 (750 for non-trading), and that for periods beginning on or after 1 April 2026 zero-emission cars and charge-points also go in 725 or 750.

Assumptions and limits

One accounting period, at most 12 months. For a shorter period the annual investment allowance and the small pools allowance are reduced in proportion (9 months gives £750,000); the calculator uses whole months where the period is whole months and days over 365 otherwise. It does not work out writing-down allowances for a period shorter than 12 months.
Not for the final period of trade. In the period a trade ceases there is no annual investment allowance or full expensing, and the pools give balancing allowances or charges.
Disposals. Proceeds from main and special rate pool assets reduce the pool; more than the pool is a balancing charge. For an asset on which full expensing was claimed, the whole proceeds are a balancing charge outside the pool, as the calculator assumes 100% was claimed. Disposals of assets that had the 50% allowance are not covered.
Cars never get the annual investment allowance, full expensing or the 40% allowance. Structures and buildings allowance (3% a year) and short-life assets are not covered.
Rates as at 25 October 2026, before the Autumn Budget on 28 October 2026.

Frequently asked questions

What is the writing-down allowance from April 2026?

For companies, 14% on the main pool for chargeable periods beginning on or after 1 April 2026, down from 18%. A period across that date uses a hybrid rate. The special rate pool stays at 6%.

Can a company claim full expensing on a car?

No. Cars never qualify for full expensing, the annual investment allowance or the 40% first-year allowance. New zero-emission cars get a 100% first-year allowance to 31 March 2027.

What is the new 40% first-year allowance?

A 40% allowance on new main-rate plant and machinery bought on or after 1 January 2026. Unlike full expensing it is allowed for plant bought for leasing, and the remaining 60% goes into the main pool.

Is the annual investment allowance reduced for a short period?

Yes. For an accounting period of 9 months it is £750,000. Companies under common control share one allowance.

Are allowances restricted when a director uses an asset privately?

Not for a company. Assets a company provides to directors or employees as part of their remuneration are treated as used wholly for the trade; the private-use restriction applies to sole traders and partnerships.

Sources

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