Did you know that over 90% of UK businesses claim capital allowances to reduce their tax bills? The Annual Investment Allowance (AIA) is one of the most valuable tax reliefs available, offering immediate 100% tax relief on qualifying equipment purchases up to a generous limit. Understanding how to claim AIA correctly can significantly improve your cash flow and free up funds to grow your business.
| Key Figures for 2026/26 | Amount (£) |
|---|---|
| Annual Investment Allowance (AIA) Limit | 1,000,000 |
| Corporation Tax Rate (Small Profits) | 19% |
| First Year Allowance for Low Emission Cars | 100% |
What is the Annual Investment Allowance?
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Use Free Tax Calculator →The Annual Investment Allowance (AIA) is a form of capital allowance that lets UK businesses deduct the full cost of qualifying capital assets from their taxable profits in the year of purchase. Instead of writing off the cost over several years, you can claim 100% tax relief immediately, improving your cash flow.
The AIA is especially beneficial for small and medium-sized enterprises (SMEs), as it covers the majority of tangible capital expenditure, such as machinery, office equipment, and some integral features of buildings.
Current AIA Limit and Eligibility
For the tax year 2026/26, the AIA limit is set at £1,000,000. This means you can claim 100% tax relief on qualifying purchases up to this amount within your accounting period. If your expenditure exceeds this limit, the excess can still be claimed as writing down allowances at the normal rate.
Eligibility for AIA generally applies to all UK businesses, including sole traders, partnerships, and limited companies, that incur capital expenditure on qualifying assets used for business purposes.
How the AIA Limit Works
The £1 million limit applies per business, not per entity. For example, if you operate multiple companies within a group, each company is entitled to its own allowance. However, if your accounting period spans more than 12 months, the limit is prorated accordingly.
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Qualifying Assets for AIA
Understanding which assets qualify for AIA is crucial to maximising your tax relief. Generally, the allowance applies to most tangible capital assets used in your business. This includes:
- Machinery and plant (e.g., manufacturing equipment, tools)
- Office furniture and equipment (e.g., desks, computers)
- Some integral features of buildings, such as electrical systems, heating, and lifts
- Vehicles used for business purposes, excluding cars with high CO2 emissions
However, some assets are excluded, such as:
- Cars with CO2 emissions over 50g/km (these attract different writing down allowances)
- Land and buildings (purchase costs)
- Assets bought for renting out
- Assets used for non-business or private purposes
How to Claim AIA on Your Tax Return
Claiming the Annual Investment Allowance correctly is essential to benefit from immediate tax relief. The way you claim depends on your business structure and type of tax return filed.
For Limited Companies: You claim AIA on your Corporation Tax return (CT600). Include the qualifying expenditure in the capital allowances section of the return. If you use accounting software, it may guide you through the entries, but always double-check figures against your records.
For Sole Traders and Partnerships: Claim AIA on your Self Assessment tax return using the Capital Allowances pages (SA103S or SA103F).
Step-by-step guide to claiming AIA
- Identify all qualifying capital expenditure incurred during the accounting period.
- Calculate the total cost of these assets, excluding VAT if you can reclaim it.
- Check if the total cost exceeds your AIA limit for that period.
- Claim 100% of qualifying expenditure up to the AIA limit on your tax return.
- Any expenditure above the limit can be claimed as writing down allowances at the appropriate rate.
- Keep detailed records and receipts for all purchases in case HMRC requests evidence.
AIA vs Other Capital Allowances
While the AIA provides full upfront relief, other types of capital allowances may apply when your expenditure exceeds the AIA limit or for assets excluded from AIA.
- First Year Allowance (FYA): Available on certain energy-efficient or environmentally friendly assets, such as low-emission cars and electric vehicle charging points, allowing 100% relief regardless of AIA.
- Writing Down Allowance (WDA): For assets not covered by AIA, you can deduct a percentage of the asset’s value each year (usually 18% or 6% depending on the asset pool).
Choosing the right mix of allowances depends on your business’s capital spend profile and future tax planning. For more detailed guidance, see our Corporation Tax Guide.
Key Takeaways
- The Annual Investment Allowance (AIA) provides 100% tax relief on qualifying assets up to £1 million in 2026/26.
- Most tangible business assets qualify, but cars with high emissions and land/buildings do not.
- Claim AIA through your tax return: CT600 for limited companies, Self Assessment for sole traders and partnerships.
- Expenditure above the AIA limit is eligible for writing down allowances at standard rates.
- Keep detailed purchase records to support your claim in case of HMRC enquiries.
Further Resources and Advice
For more information on capital allowances and tax reliefs available to your business, GOV.UK offers comprehensive guidance on capital allowances. You can also consult HMRC’s manuals and official guidance to stay up to date on any changes.
If you’re unsure whether your assets qualify or how best to structure your capital expenditure, consider consulting a qualified accountant or tax adviser. They can help you optimise your claims and ensure compliance with HMRC rules.
To understand how AIA fits into your overall tax planning, you might find it useful to read our article on Sole Trader vs Limited Company.
What happens if my business exceeds the £1 million AIA limit?
If your qualifying capital expenditure exceeds the £1 million AIA limit in the accounting period, you can claim 100% relief on the first £1 million. The amount above this is added to your writing down allowance pool and claimed at the appropriate writing down allowance rate.
Can I claim AIA on second-hand equipment?
Yes, AIA can be claimed on both new and second-hand qualifying assets, provided they are used for your business. Ensure you keep purchase invoices and proof that the assets are solely for business use.
Does AIA apply to leased or rented equipment?
Generally, AIA applies to assets you own outright. If you lease or rent equipment, you cannot claim AIA, but the lease payments may be deductible as business expenses instead. Check HMRC guidance for specific lease arrangements.
Official Sources
* GOV.UK: Set up a business · * HMRC: Income Tax rates · * HMRC: Corporation Tax · * HMRC: VAT registration