Capital Allowances: How to Claim Tax Relief on Business Assets

Capital allowances are a crucial aspect of the UK tax system, offering businesses significant tax relief on qualifying capital expenditure. Instead of deducting the full cost of an asset from profits in the year of purchase, capital allowances allow businesses to write off the cost over time, reducing their taxable profits. This guide provides a comprehensive overview of the various capital allowances available in the UK for the 2026/27 tax year, including the Annual Investment Allowance (AIA), Full Expensing, Writing Down Allowances (WDA), First Year Allowances (FYAs), and the Structures and Buildings Allowance (SBA). Understanding and effectively claiming these allowances can lead to substantial tax savings and improved cash flow for businesses of all sizes.

TL;DR Summary

Key Capital Allowances Explained

Annual Investment Allowance (AIA)

The Annual Investment Allowance (AIA) is a generous tax relief that allows businesses to deduct the full cost of most plant and machinery from their profits before tax, up to a certain annual limit. For the 2026/27 tax year, the AIA limit remains at £1 million [1]. This means that for qualifying expenditure up to this amount, businesses can claim 100% tax relief in the year of purchase, significantly reducing their tax bill. The AIA is available to most businesses, including sole traders, partnerships, and companies.

Qualifying Assets for AIA:

The AIA generally applies to most plant and machinery, including:

• Vans, lorries, and other commercial vehicles (but not cars).
• Machinery, such as lathes, presses, or diggers.
• Office equipment, including computers, printers, and office furniture.
• Tools and equipment.
• Fixtures and fittings, such as kitchen equipment or sanitaryware.
• Integral features of a building, like electrical systems, lighting, and heating.

Pros and Cons of AIA:

Full Expensing

Introduced to stimulate business investment, Full Expensing allows companies subject to Corporation Tax to claim 100% capital allowances on qualifying new main rate plant and machinery in the year of purchase. This is effectively a permanent 100% first-year allowance. For special rate (long-life) assets, a 50% first-year allowance is available [2]. Full expensing applies to expenditure incurred from 1 April 2023 onwards.

Eligibility and Qualifying Assets for Full Expensing:

• Eligibility: Only companies subject to Corporation Tax can claim Full Expensing. It is not available to unincorporated businesses (sole traders or partnerships).
• Main Rate Assets: New and unused plant and machinery that would ordinarily qualify for the main rate (18%) Writing Down Allowance. Examples include computers, office furniture, and most machinery.
• Special Rate Assets: New and unused plant and machinery that would ordinarily qualify for the special rate (6%) Writing Down Allowance, such as integral features of a building (e.g., electrical systems, lifts) and long-life assets. These qualify for a 50% first-year allowance.

Pros and Cons of Full Expensing:

Writing Down Allowance (WDA)

Writing Down Allowances (WDAs) are claimed on assets that do not qualify for AIA or Full Expensing, or for expenditure exceeding the AIA limit. WDAs allow businesses to deduct a percentage of the asset's remaining value each year. Assets are typically pooled into two main categories:

• Main Pool: For most plant and machinery, the WDA rate for 2026/27 is 18% per year on a reducing balance basis. However, it's important to note that legislation will be introduced in Finance Bill 2025-26 to adjust the main rate of WDA to 14% from 1 January 2026 [3].
• Special Rate Pool: For certain assets, such as integral features of buildings, long-life assets, and thermal insulation, the WDA rate is 6% per year on a reducing balance basis [3].

How WDA Differs from AIA/Full Expensing:

Unlike AIA and Full Expensing, which provide 100% relief in the first year, WDAs spread the tax relief over several years. This means the tax benefit is realized more slowly, but it still provides valuable relief for assets that don't qualify for immediate write-offs.

First Year Allowances (FYAs)

First Year Allowances (FYAs) enable businesses to claim 100% of the cost of certain assets in the year of purchase, similar to AIA, but often without an annual limit or for specific types of investments. For 2026/27, key FYAs include:

• Zero-Emission Cars and Electric Vehicle Chargepoints: Businesses can claim 100% FYA on the purchase of new and unused zero-emission cars and electric vehicle chargepoints. This allowance has been extended by 12 months to 31 March 2027 (for corporation tax purposes) [5]. This is a significant incentive for businesses to transition to greener transport options.
• Energy-Efficient Equipment: Historically, FYAs were available for certain energy-efficient plant and machinery. While many of these specific allowances have been superseded by AIA and Full Expensing, businesses should always check the latest HMRC guidance for any specific qualifying energy-efficient technologies that may still attract a 100% FYA.
• New 40% FYA for Main Rate Expenditure: From 1 January 2026, a new 40% FYA will be introduced for certain expenditure on plant and machinery allocated to the main pool. This will benefit businesses unable to claim Full Expensing [3].

Structures and Buildings Allowance (SBA)

The Structures and Buildings Allowance (SBA) provides tax relief for qualifying expenditure on new non-residential structures and buildings. Businesses can claim an annual allowance of 3% on a straight-line basis over 33 and a third years [4]. This allowance aims to encourage investment in new commercial properties and renovations.

Qualifying Expenditure for SBA:

SBA applies to costs incurred on:

• Construction or acquisition of new non-residential buildings.
• Renovation or conversion of existing non-residential buildings.
• Costs directly associated with the construction, such as design fees, planning permission, and demolition costs.

Qualifying vs. Non-Qualifying Assets

Understanding which assets qualify for capital allowances is crucial for accurate tax planning. While the rules can be complex, here's a general guide:

How to Claim Capital Allowances

The method for claiming capital allowances depends on your business structure:

For Sole Traders and Partnerships (Self Assessment)

1. Calculate Your Allowances: Determine the total capital allowances you can claim for the tax year based on your qualifying expenditure and the applicable allowance rates (AIA, WDA, FYAs, SBA).
2. Complete Your Tax Return: Enter the total amount of capital allowances in the 'Capital allowances' section of your Self Assessment tax return (SA103F for sole traders, SA104F for partnerships).
3. Keep Records: Maintain detailed records of all asset purchases, including invoices, dates of purchase, and how the assets are used in your business. This is essential for HMRC inquiries.

For Companies (CT600 Corporation Tax Return)

1. Calculate Your Allowances: Work out the total capital allowances for your accounting period, considering AIA, Full Expensing, WDA, FYAs, and SBA.
2. Complete Your CT600: Include the capital allowances figure in your company's Corporation Tax return (CT600). This will reduce your company's taxable profits.
3. Submit Computations: Provide detailed capital allowance computations as part of your company's tax return submission to HMRC.

Impact on Business Profitability

Capital allowances directly reduce a business's taxable profits, leading to a lower tax liability. For example, a company investing £500,000 in new main rate plant and machinery could claim Full Expensing, reducing its taxable profits by £500,000 in the year of purchase. At a Corporation Tax rate of 25%, this would result in a tax saving of £125,000. This immediate or accelerated tax relief can significantly improve cash flow, allowing businesses to reinvest in growth, pay down debt, or improve their financial resilience.

Choosing the Right Accounting Software

Managing capital allowances, tracking assets, and preparing accurate tax returns can be complex. Modern accounting software solutions offer features that streamline these processes, from automated asset registers to integrated tax calculation tools. Choosing the right software can save time, reduce errors, and ensure you claim all eligible allowances.

Conclusion

Capital allowances are a vital mechanism for businesses in the UK to reduce their tax burden and encourage investment. By understanding the nuances of AIA, Full Expensing, WDAs, FYAs, and SBA, businesses can strategically plan their capital expenditure to maximise tax relief. Staying informed about the latest HMRC rules and leveraging appropriate accounting tools are key to unlocking the full benefits of capital allowances.

References

1. GOV.UK. (n.d.). Claim capital allowances: Annual investment allowance. Available at: https://www.gov.uk/capital-allowances/annual-investment-allowance
2. GOV.UK. (n.d.). Capital allowances: new first-year allowance and reducing main rate of writing down allowances. Available at: https://www.gov.uk/government/publications/new-first-year-allowance-and-main-rate-of-writing-down-allowances/capital-allowances-new-first-year-allowance-and-reducing-main-rate-writing-down-allowances
3. Deloitte. (2026, January 13). Tax rates 2026/27. Available at: https://taxscape.deloitte.com/taxtables/deloitte-uk-tax-rates-2026-27.pdf
4. In-Accountancy. (n.d.). 2025/2026 Tax Rates. Available at: https://www.in-accountancy.co.uk/resources/tax-rates/2025-2026/
5. GOV.UK. (n.d.). First-year allowances for zero-emission cars and electric vehicle chargepoints. Available at: https://www.gov.uk/government/publications/first-year-allowances-for-zero-emission-cars-and-electric-vehicle-chargepoints