Capital Allowances and the Annual Investment Allowance for Sole Traders 2026/27

The AIA lets businesses, including sole traders, deduct the full cost of most qualifying equipment and machinery from taxable profit in the year of purchase, up to an annual limit of £1 million, rather than spreading the deduction over several years through standard capital allowances rates.

Most plant and machinery used in the business qualifies, including tools, computers, office equipment, machinery, vans and some other business vehicles (cars are generally excluded from the AIA, though they may qualify for separate writing-down allowances). The equipment needs to be genuinely used for the business, not for personal use.

No — cars are specifically excluded from the Annual Investment Allowance. Cars instead attract writing-down allowances at a rate depending on their CO2 emissions, spread over multiple years rather than deducted in full immediately, though vans and most other commercial vehicles can qualify for the AIA.

The AIA deduction reduces taxable profit pound for pound in the year of purchase, which in turn reduces the Income Tax and Class 4 National Insurance due on that profit — for a basic rate taxpayer, £1,000 of AIA-qualifying spend can reduce the tax and NI bill by up to £280 (20% income tax + 6% Class 4 NI at 2026/27 rates), and more for a higher rate taxpayer.

Very few sole traders will approach this limit, but any qualifying spend above £1 million in a single accounting period falls back to the standard writing-down allowance rates (generally 18% or 6% per year on a reducing balance basis, depending on the asset type) rather than being deducted in full immediately.

For most types of equipment, sole traders using the simplified cash basis can generally claim the cost of equipment as an allowable expense directly (rather than through formal capital allowances) in the way that broadly achieves the same practical outcome as claiming AIA, though cars are treated differently under the cash basis with a fixed mileage-rate alternative typically used instead.

No — they're separate reliefs. The AIA covers most plant and machinery up to the £1 million annual limit. The 100% First Year Allowance is a distinct relief that has, at various times, applied specifically to certain categories like electric vehicle charge points or, for companies, certain very low emission assets — the specific conditions for each should be checked separately rather than assumed to be interchangeable.

Yes — claiming a large AIA deduction can turn what would otherwise have been a taxable profit into a loss for that year. This loss can potentially be carried forward against future profits, carried back against a previous year's profit in some circumstances, or in some cases offset against other income, depending on the specific loss relief rules and the individual's situation.

No — claiming the AIA is optional, and a sole trader can choose to claim less than the full amount available (or none at all) if, for example, they'd rather spread the tax relief over several years using standard writing-down allowances, perhaps because their profit is currently below the personal allowance and an immediate deduction wouldn't provide any tax benefit that year.

A sole trader buying £8,000 of qualifying equipment (tools, a work van, computer equipment) can deduct the full £8,000 from their taxable profit for the year via the AIA. If they're a basic rate taxpayer already above the personal allowance, this saves 20% Income Tax (£1,600) plus 6% Class 4 National Insurance (£480) — a total saving of £2,080 in the year of purchase, rather than that relief being spread over several years.