The £1 Million Annual Investment Allowance That Many Businesses Overlook

What if some of the equipment your business has already purchased could reduce your tax bill more than you expected? Many UK businesses invest in machinery, technology and other essential assets without fully considering the tax relief available on those purchases.

The Annual Investment Allowance (AIA) offers a valuable opportunity to deduct up to £1 million of qualifying expenditure from taxable profits. Yet the real opportunity isn’t necessarily in making a large investment. Even everyday business purchases could qualify for immediate tax relief, potentially reducing your tax liability.

With changes to capital allowances taking effect in 2026, it’s worth taking a closer look at what qualifies under AIA, how much your business could save and whether you’re making full use of the relief available.

What Is Annual Investment Allowance?

Annual Investment Allowance is a capital allowance that allows businesses to claim a 100% deduction on qualifying plant and machinery expenditure. Rather than spreading the deduction over several years, businesses can generally claim the full eligible amount in the accounting period in which the expenditure is incurred.

For example, if a company purchases £25,000 worth of qualifying machinery, it may be able to deduct the entire £25,000 from its taxable profits. This can provide an immediate tax benefit instead of relying on smaller annual deductions through writing-down allowances.

The relief is available to eligible limited companies and sole traders, as well as qualifying partnerships. However, the amount that can be claimed depends on the business structure and the applicable capital allowance rules.

According to HMRC’s Annual Investment Allowance guidance, qualifying businesses can deduct the full value of eligible assets, subject to the available allowance.

How Much Annual Investment Allowance Can You Claim in 2026?

The AIA limit remains £1 million for 2026, meaning businesses can generally deduct up to this amount of qualifying expenditure during a standard 12-month accounting period.

However, the full allowance does not automatically apply to every business. Shorter accounting periods have proportionately reduced limits, while companies under common control may need to share a single allowance.

These figures assume the standard £1 million limit applies without additional restrictions.

It is important to understand that AIA is a deduction against taxable profits, not a payment from HMRC. A £50,000 qualifying purchase may provide a £50,000 tax deduction, but the actual tax saving will depend on the business’s circumstances.

Source: Claim capital allowances – Annual investment allowance – GOV.UK

Which Business Purchases Qualify for AIA?

AIA is not limited to large machinery purchases. Many assets used in everyday business operations may qualify, making the allowance relevant to businesses across different industries.

Examples of potentially qualifying expenditure include:

• Computers and IT equipment: Business laptops, servers and other qualifying technology.
• Machinery and tools: Manufacturing equipment, construction machinery and specialist tools.
• Office equipment: Desks, chairs and qualifying office furniture.
• Commercial vehicles: Vans, lorries and other qualifying goods vehicles.
• Building fixtures: Certain electrical installations, heating systems and other qualifying fixtures.
• Second-hand equipment: Previously used plant and machinery purchased for qualifying business purposes.

Nevertheless, some purchases are excluded. Business cars do not qualify for AIA, even if they are used entirely for work. Assets originally acquired for personal use and items received as gifts are also excluded.

Businesses investing in commercial property should take particular care, as qualifying fixtures may be eligible even though the cost of purchasing land or constructing a building generally is not.

Not every business purchase qualifies for AIA, and some costs may instead be treated as ordinary business expenses. Our guide to allowable and non-allowable business expenses explains how different types of expenditure are treated for tax purposes. 

How Much Corporation Tax Could Your Business Save?

The financial value of AIA becomes clearer when considering its effect on Corporation Tax.

Suppose a UK limited company has taxable profits of £300,000 before capital allowances and purchases qualifying machinery costing £40,000. Assuming the company has sufficient AIA available, the deduction would reduce its taxable profits to £260,000.

This simplified example assumes a 12-month accounting period, no associated companies and no other tax adjustments.

In this scenario, claiming AIA would reduce the company’s Corporation Tax liability by £10,000. The company still pays for the machinery, but the tax deduction reduces the overall after-tax cost of its investment.

The saving will not be the same for every business. Companies paying Corporation Tax at the 19% small profits rate will have a different outcome from those paying the 25% main rate. Where profits fall between the applicable thresholds, Corporation Tax marginal relief can also affect the calculation. 

You can check the applicable rates in HMRC’s Corporation Tax guidance. 

Annual Investment Allowance vs First-Year Allowances

Although AIA and first-year allowances both provide tax relief on qualifying capital expenditure, they operate differently.

AIA generally allows a 100% deduction on eligible plant and machinery expenditure, including qualifying second-hand equipment, up to the available annual limit. Other first-year allowances have their own eligibility requirements and may apply where AIA is unavailable or has already been fully used.

This distinction has become more important following the introduction of the 40% first-year allowance in January 2026, alongside the reduction in the main writing-down allowance rate from 18% to 14% in April 2026.

The most suitable relief depends on the type of expenditure and the business’s tax position. Businesses making substantial investments should consider the available allowances before deciding how to claim.

For a closer look at the newer rules, read our guide on First Year Allowance on Equipment and Machinery, which explains how the 2026 changes affect qualifying business investments.

How to Claim Annual Investment Allowance

AIA is claimed through the relevant business tax return rather than through a separate application to HMRC.

Limited companies normally claim through their Corporation Tax return (CT600), while eligible sole traders and partnerships claim through their respective tax returns. Sole traders using the cash basis should check the separate rules for equipment purchases, as many such costs are deducted directly as business expenses.

Before claiming, businesses should check that the expenditure qualifies and retain supporting purchase records. The timing also matters because AIA is generally claimed in the accounting period when the expenditure is treated as incurred.

For businesses approaching their year-end, reviewing planned equipment purchases may help determine when the relief will become available. However, buying unnecessary equipment simply to obtain a tax deduction is unlikely to make commercial sense.

Are You Making the Most of Your Annual Investment Allowance?

AIA isn’t just for businesses making major investments. Even smaller purchases of qualifying equipment could reduce your taxable profits. Understanding what qualifies and when to claim can help ensure valuable tax relief isn’t overlooked.

At Artifin Accountants, we help UK businesses identify eligible capital allowances and make the most of available tax relief.

Contact our team to find out how the Annual Investment Allowance could benefit your business.