Full Expensing Explained: How to Use Capital Allowances to Optimise Investment in 2026

The government’s decision to make 100% full expensing a permanent feature of the UK tax system marks a major opportunity for businesses to reduce their corporation tax liabilities through smart investment. Full expensing allows companies to deduct 100% of qualifying capital expenditure on certain assets from taxable profits in the year of purchase — effectively giving an immediate tax relief. This permanent measure is designed to encourage long-term investment in equipment, technology, and infrastructure.

In this detailed guide, we’ll explain how full expensing works, what assets qualify, how it compares to other capital allowances, and practical strategies to help you maximise your tax savings in 2026 and beyond.

What full expensing means for UK businesses

Full expensing is a capital allowance that enables companies subject to Corporation Tax to claim a 100% deduction on the cost of qualifying plant and machinery in the same year the expenditure occurs. This policy, first introduced as a temporary relief in 2021, was made permanent to encourage UK businesses to invest in productivity-enhancing assets.

For instance, if a business spends £200,000 on new machinery, it can immediately deduct that full amount from its taxable profits for the year — reducing its Corporation Tax liability by £50,000 (assuming a 25% tax rate). This creates a powerful incentive to reinvest profits in operational improvements and technology upgrades.

Key benefits:

• Immediate tax relief improves cash flow and reduces taxable profit.
• Encourages investment in energy-efficient and high-value equipment.
• Provides certainty for long-term business investment planning.
• Simplifies capital expenditure decisions compared to older allowance schemes.

How the 100% capital allowance works

Under the regime, companies can deduct the full cost of qualifying assets from their taxable profits in the same accounting period. This replaces the slower Writing Down Allowance (WDA) method, which spread tax relief over several years.

Example:
If your business invests £120,000 in production machinery, you can deduct the full £120,000 from taxable profits, saving £30,000 in Corporation Tax at the 25% rate.

Eligible assets and excluded categories

To qualify for full expensing, assets must be new (not second-hand) and fall within the main pool of plant and machinery.

Qualifying assets include:

• Manufacturing equipment and industrial machinery
• Office furniture and fittings
• Computer servers, IT systems, and software hardware
• Commercial vehicles (excluding cars)
• Construction, logistics, and production assets

Excluded categories:

• Used or second-hand assets
• Buildings and land
• Cars (though separate capital allowances may apply)
• Assets purchased for leasing to third parties

If your expenditure doesn’t qualify for full expensing, you may still claim relief under the Annual Investment Allowance (AIA) or Writing Down Allowance (WDA), ensuring tax efficiency for different types of assets.

Comparing full expensing vs Annual Investment Allowance (AIA)

Both full expensing and the AIA offer immediate 100% tax relief on qualifying purchases, but they differ in scope and eligibility.

Tip: Full expensing is ideal for larger firms or businesses planning major investment projects. Smaller companies with modest annual capital expenditure may still prefer the AIA’s simpler approach.

Practical examples of full expensing in action

Example 1: Manufacturing business
A manufacturing company invests £500,000 in robotics and automation. Under full expensing, it deducts the entire £500,000 from its taxable profit, saving £125,000 in Corporation Tax.

Example 2: Tech startup
A software firm spends £150,000 upgrading its servers and digital infrastructure. Full expensing allows a £37,500 tax saving in the same year.

Example 3: Construction company
A construction firm purchases £250,000 of new plant and heavy-duty equipment. The business deducts the full amount, improving cash flow and freeing capital for expansion.

These examples demonstrate how full expensing can accelerate reinvestment and reduce financing pressures, particularly for equipment-heavy industries.

Tax planning strategies to maximise savings

To get the most out of full expensing, incorporate it into your business’s long-term investment and tax strategy.

1. Plan your timing – Purchase qualifying assets before your accounting year ends to benefit from immediate deductions.
2. Combine with other allowances – Use the AIA for used assets and full expensing for new ones. This dual approach ensures no qualifying expenditure is overlooked.
3. Keep detailed records – Maintain invoices and asset documentation for HMRC verification.
4. Review disposal implications – If you sell an asset claimed under full expensing, a balancing charge (tax adjustment) may apply.
5. Integrate with management accounts – Use regular reporting to track asset performance and return on investment.

For more tailored guidance, visit (management accounts services) or speak to a specialist about capital expenditure planning.

Final thoughts

Full expensing is one of the most powerful tools UK businesses can use to improve cash flow and reduce tax bills. By claiming 100% deductions upfront, companies can invest confidently in new equipment, technology, and production capabilities.

Whether you’re a manufacturer upgrading production lines or a growing tech firm expanding infrastructure, full expensing can help you reinvest more effectively.

Talk to Fusion Accountants about structuring your investments to make the most of full expensing and other capital allowance opportunities.