Capital Allowances for Plant & Machinery: Maximise Your Tax Relief

What Are Capital Allowances for Plant & Machinery?

When your limited company buys assets used in the business — computers, machinery, vehicles, office furniture — you cannot simply deduct the full cost as a business expense in your accounts. Instead, you claim capital allowances, which give you tax relief on the depreciation of those assets over time. The good news is that several generous reliefs mean you can often deduct 100% of the cost in the year of purchase.

The Annual Investment Allowance (AIA): Your First Port of Call

The Annual Investment Allowance (AIA) allows most businesses to deduct 100% of qualifying plant and machinery costs in the tax year of purchase, up to a limit of £1 million per year. This limit has been permanently set at £1 million since April 2023, giving companies long-term certainty when planning capital expenditure.

• The AIA applies to most plant and machinery, including tools, computers, commercial vehicles, and fitted fixtures.
• It does not apply to cars — these follow separate rules based on CO2 emissions.
• If your company is part of a group or under common control, the £1 million limit is shared across the group.
• Expenditure must be incurred wholly and exclusively for business purposes.

First Year Allowances (FYAs): 100% Relief on Specific Assets

Separate from the AIA, First Year Allowances (FYAs) give 100% relief in year one on specific categories of asset. The most important for company directors right now is the Full Expensing relief, made permanent from April 2024. This allows companies to deduct 100% of the cost of new, unused main pool plant and machinery (such as equipment and machinery) and 50% of special rate pool assets (such as integral features like electrical systems and long-life assets) in the year of purchase — with no monetary cap.

• Full Expensing is available to limited companies only — sole traders and partnerships cannot use it, but can use AIA instead.
• Assets must be new and unused — second-hand equipment does not qualify for Full Expensing.
• A 100% FYA also remains available for zero-emission cars and certain energy-efficient or environmentally beneficial plant.

Common HMRC Challenges to Watch Out For

HMRC scrutinises capital allowance claims carefully. Here are the most frequent areas of challenge:

• Mixed personal and business use: If an asset is used partly for personal purposes — a laptop used at home, for example — HMRC may restrict the claim. You must be able to demonstrate the business use proportion and apply it consistently.
• Cars misclassified as commercial vehicles: A car and a commercial vehicle are treated very differently. Double-cab pick-ups, for instance, have specific rules following a change in HMRC's position in 2024. Always verify the classification before claiming.
• Claiming on assets not owned by the company: You can only claim allowances on assets that the company owns. If you personally bought an asset and use it in the business, the company cannot claim — though you may be able to claim a use-of-own-assets deduction instead.
• Timing of expenditure: Capital allowances are claimed in the accounting period in which the expenditure is incurred, not when the invoice is paid. For accruals-basis companies, this is the date the obligation to pay arises.
• Lease versus purchase: Capital allowances only apply to purchased assets. Leased assets are generally deducted as revenue expenses under the lease payments, not via capital allowances.

Practical Steps to Maximise Your Claim

To make sure your company claims every pound it is entitled to, keep a detailed fixed asset register with purchase dates, costs, and business-use percentages. Review asset purchases before your year end — if you are close to the AIA limit, timing a large purchase into the right accounting period can make a significant difference. Work with your accountant to ensure Full Expensing and AIA are applied in the most tax-efficient order, particularly if you have both new and second-hand assets in the same year.

Getting capital allowances right is one of the most straightforward ways to reduce your corporation tax bill. With Full Expensing now permanent, limited companies have an exceptional opportunity to invest in their business and receive immediate, full tax relief.