Capital allowances calculator for companies

Free tool

Accounting period

Accounting period start date

For example, 1 4 2026. The period must start on or after 1 April 2023.

Day Month Year

Accounting period end date

For example, 31 3 2027. A Corporation Tax accounting period is 12 months or less.

Day Month Year

Date of the purchases (optional)

Only matters for new zero-emission cars, whose 100% allowance is for spending up to 31 March 2027. Leave blank to use the period end.

Day Month Year

What did the company buy?

Enter the cost of each kind of item bought in this period. Leave blank anything that doesn't apply.

New plant, machinery and vans

New and unused equipment, machinery, tools, computers, furniture and vans. Not cars.

Second-hand plant, machinery and vans

The same kinds of item, bought second-hand.

New integral features and other special rate items

New electrical, lighting, heating, water and air-conditioning systems and lifts in a building, thermal insulation, solar panels and long-life assets.

Second-hand integral features and other special rate items

The same kinds of item, bought second-hand.

New zero-emission cars

New and unused fully electric cars (0 g/km CO2). A second-hand electric car goes in the next box.

Other cars with CO2 of 50 g/km or less

Including second-hand electric cars.

Cars with CO2 over 50 g/km

New or second-hand.

Pools brought forward

The balances left in the company's pools at the end of the previous period. Enter 0 or leave blank for a new company.

Main pool brought forward

Special rate pool brought forward

Did the company sell anything?

For each, enter the sale price, or what the item cost if that is lower.

Main pool items sold

Items bought in an earlier period that had the annual investment allowance or went into the main pool.

Items sold that had full expensing

Items whose whole cost had full expensing. The whole sale price is added to profits.

Is the company in a group?

Annual investment allowance given to related companies (optional)

Companies in a group or controlled by the same person share one £1,000,000 allowance. Enter the amount the other companies use for this period.

For a UK trading company. Amounts in pounds; you can type £ and commas.

Example

Worked example

Accounting period start date: 1 April 2026; Accounting period end date: 31 March 2027; New plant, machinery and vans: £40,000; Second-hand plant, machinery and vans: £15,000; Main pool brought forward: £60,000. Enter your own details to replace this example.

For the period 1 April 2026 to 31 March 2027, the company can claim £63,400 of capital allowances: £55,000 annual investment allowance and £8,400 main pool writing-down allowance (14%). £51,600 stays in the main pool for later years. At the 25% main rate that is about £15,850 less Corporation Tax (£12,046 at 19%).

Total capital allowances: £63,400
Annual investment allowance: £55,000 (of £1,000,000 available)
Main pool writing-down allowance (14%): £8,400
Special rate pool writing-down allowance (6%): £0
Main pool carried forward: £51,600
Special rate pool carried forward: £0
Illustration: Corporation Tax saved at 25%: £15,850
Illustration: Corporation Tax saved at 19%: £12,046

How the pools work out

Main pool and special rate pool working for 2026-04-01 to 2027-03-31
	Main pool	Special rate pool
Brought forward	£60,000	£0
Added this period	£0	£0
Less sale proceeds	£0	£0
Balance	£60,000	£0
Less writing-down allowance Main 14%; special rate 6%	£8,400	£0
Carried forward	£51,600	£0

Where each purchase went

Allowances on each kind of purchase
Purchase	Cost	Annual investment allowance	First-year allowance	Into the pool
New plant, machinery and vans	£40,000	£40,000	£0	£0
Second-hand plant, machinery and vans	£15,000	£15,000	£0	£0

The annual investment allowance is used first, where it is worth most: second-hand special rate items, then second-hand main rate items, then new special rate items, then new main rate items. Full expensing and the 50% first-year allowance cover spending above it. The relief is the same, but an asset covered by the annual investment allowance doesn't make its whole sale price a balancing charge when it is sold.
The tax figures are an illustration: the rate depends on the company's total taxable profits (19% up to £50,000, 25% over £250,000, and an effective 26.5% on profits between the two under marginal relief). Taxley's Corporation Tax calculator works out the full bill: https://taxley.co.uk/corporation-tax-calculator.
Not covered: the 40% first-year allowance for spending from 1 January 2026, assets bought to lease out, the structures and buildings allowance, property letting businesses, the period in which a company stops trading, purchases from connected people, private use, and sales of special rate items.
The calculator works in whole pounds: costs are rounded down and sale proceeds up.

Sources: GOV.UK: Annual Investment Allowance GOV.UK: Check if you can claim full expensing or 50% first-year allowances GOV.UK: Writing down allowances – rates and pools legislation.gov.uk: Capital Allowances Act 2001, Part 2 (plant and machinery)