The Autumn Budget always brings a flurry of headlines, but if you own a business and invest in plant and machinery, one announcement deserves your attention: changes to the Writing Down Allowance (WDA). While it might sound technical, these changes could affect your tax relief and investment strategy from 2026 onwards.
Understanding Writing Down Allowance for plant and machinery
Capital allowances are the government’s way of giving businesses tax relief on certain types of expenditure – typically plant and machinery.
Instead of claiming the full cost in one go, you spread the relief over several years. That’s where the Writing Down Allowance comes in.
Currently, most businesses claim WDA at 18% per year on the “main pool” of qualifying assets. It’s a steady, predictable way to reduce your taxable profits over time.
2026 Capital Allowance Updates: Lower rates and new first-year relief
From April 2026, the main rate of WDA will drop from 18% to 14%. For unincorporated businesses, this kicks in from 6 April 2026.
Why does this matter? A lower rate means it will take longer to write off the cost of your assets. For example, under the current 18% rate, it takes around 10 years to claim most of the relief. At 14%, that stretches closer to 13 years.
But there’s more. To soften the blow, the government is introducing a 40% First-Year Allowance (FYA) for main-rate expenditure from 1 January 2026. This is particularly helpful for businesses that can’t use full expensing or the Annual Investment Allowance (AIA)—think leasing companies or sole traders.
Real-world calculation: £100k machinery purchase example
Let’s say you buy £100,000 of new machinery in April 2026. Under the old 18% rate, your first-year claim would be £18,000. Under the new 14% rate, it’s £14,000—a £4,000 difference. Over time, that gap widens and the cumulative impact on your tax position becomes more significant.
If you qualify for the new 40% FYA, you could claim £40,000 upfront, plus WDA on the balance. That’s a significant improvement and demonstrates why understanding which reliefs you’re eligible for really matters.
Qualifying expenditure: what counts toward each relief?
Before you start planning, it’s important to understand what actually qualifies for these different types of relief.
Writing Down Allowance (WDA)
The main pool covers most plant and machinery, including equipment, computers, tools, and commercial vehicles. Even some costs within land and buildings can be considered. Essentially, if it’s a tangible asset you use in your business that wears out over time, it likely qualifies. However, cars typically go into a separate pool with different rates.
The new 40% First-Year Allowance
The new FYA applies to main-rate expenditure that would normally go into your main pool for WDA purposes. This means it covers the same types of assets mentioned above, subject to the asset being new and not second-hand. The key advantage is that you get 40% relief upfront in the first year, with the remaining balance then subject to the 14% WDA in subsequent years.
Full Expensing
This is only available to companies (not sole traders or partnerships). It gives 100% relief in the year of purchase on qualifying new plant and machinery. If your business is incorporated and you’re making significant investments in new equipment, this is often the most generous relief available.
Annual Investment Allowance (AIA)
Most businesses can claim up to £1 million per year through the AIA on qualifying plant and machinery. This gives you 100% relief upfront, regardless of whether you’re incorporated or not. Once you’ve exceeded this cap, you’ll need to look at WDA, FYA, or full expensing for any additional expenditure.
The interaction between these reliefs matters. For example, if you’re a limited company buying £1.5 million of equipment, you’d typically claim £1 million through AIA and the remaining £500,000 through full expensing. But if you’re a sole trader in the same position, that extra £500,000 would now benefit from the 40% FYA rather than just the 14% WDA.
Government incentives for business investment: the reasoning behind reform
The government wants to encourage investment while simplifying the system. Not everyone can access the more generous reliefs like full expensing, so the new FYA offers a middle ground for those businesses left out—particularly unincorporated businesses and leasing companies that have historically relied more heavily on WDA.
How the changes affect different business types
Understanding how these changes impact your specific situation is crucial for effective tax planning. The effects vary considerably depending on your business structure and investment patterns.
Companies with historic expenditure pools
Companies with historic pools of expenditure that have been claiming WDA for years will see slower relief going forward, which means managing the tax implications over a longer timeframe. This translates to higher taxable profits in the short to medium term, so it’s important to factor this into your forecasts and ensure you’re prepared for the impact on your working capital.
Sole traders and partnerships
Sole traders and partnerships often rely heavily on WDA, so this reduction in the rate will have a noticeable effect on their tax planning and cash flow management. However, the new 40% FYA provides a valuable boost for new investments, partially offsetting the impact of the lower WDA rate.
Leasing companies
Leasing businesses, which are typically excluded from full expensing, will find the new FYA particularly valuable as it offers a meaningful alternative route to tax relief that wasn’t previously available to them.
Businesses exceeding Annual Investment Allowance limits
If you’re a business that regularly exceeds the £1m AIA cap, understanding how WDA and FYA work together becomes even more important for optimizing your tax position. The new FYA can provide substantial upfront relief on expenditure above the AIA threshold, significantly improving cash flow in the year of investment compared to relying solely on WDA.
Strategic tax planning: timing your capital investments
Timing is everything when it comes to maximizing your tax relief. If you’re considering major investment in plant and machinery, think about accelerating purchases before April 2026 to benefit from the current 18% rate. Once the changes take effect, you’ll want to make full use of the new 40% FYA for qualifying expenditure from January 2026.
It’s also a good moment to review your overall capital allowance strategy, including how full expensing and AIA fit into your plans. Consider your multi-year investment pipeline and how the timing of purchases could be optimized across the transition period.
Taking action: next steps for business owners
The Autumn Budget 2025 changes aren’t just a tweak—they could reshape how businesses plan investment. The key takeaway? Don’t leave this to chance. Speak to your tax advisor now to make sure you’re maximising relief and avoiding surprises.
