Annual Investment Allowance (AIA) Checker (2026/27).

The AIA provides a 100% first-year deduction for qualifying plant and machinery expenditure up to £1,000,000 per year. This means the full cost can be deducted from taxable profits in the year of purchase — giving an immediate CT saving rather than spreading the relief over several years via Writing Down Allowances.

Most plant and machinery qualifies for AIA — including equipment, machinery, computers, commercial vehicles, and integral building features. Cars do not qualify for AIA but can claim Writing Down Allowances. The AIA does not apply to assets you already owned before becoming a business owner, or assets bought from connected parties.

For 2026/27, eligible new main-rate expenditure not covered by AIA may qualify for the permanent 40% first-year allowance. The ongoing main-pool Writing Down Allowance is 14%, while the special-rate pool remains 6%. Eligibility and allocation order matter, so check mixed or excluded expenditure carefully.

Cars are excluded from AIA and the 40% first-year allowance. New and unused zero-emission cars can qualify for a 100% first-year allowance. Cars at 50g/km or less normally enter the 14% main-rate pool; cars above 50g/km enter the 6% special-rate pool. A second-hand electric car does not get the 100% allowance.

Yes, AIA applies to second-hand plant and machinery as well as new assets, provided you buy them at arm's length. Assets bought from connected persons (such as associates or related companies) are excluded from AIA.