Capital Allowances Explained: A Guide for Contractors and Construction Companies (2026/27)

Every growing construction business invests in equipment.

Whether you're buying a new van, excavator, scaffolding, power tools, office equipment or a site cabin, these purchases can help your business grow—but they can also reduce your tax bill.

Many construction company owners know they can "claim tax relief" on business assets, but fewer understand how Capital Allowances work, what qualifies, or how to maximise the relief available.

Understanding Capital Allowances is an important part of construction accounting because it allows businesses to deduct qualifying capital expenditure from their taxable profits. This can reduce the amount of Corporation Tax your company pays while improving cash flow and supporting future investment.

For contractors and construction companies that regularly purchase plant, machinery and equipment, Capital Allowances can represent one of the most valuable tax reliefs available.

In this guide, we'll explain what Capital Allowances are, which assets qualify, the different types of relief available and how construction businesses can benefit.

Allowance	Rate	Who It's For	Typical Construction Example
Annual Investment Allowance (AIA)	100% up to £1m annual limit	Most businesses	Vans, excavators, scaffolding
Full Expensing	100% (qualifying new assets)	Limited companies	New plant and machinery
First-Year Allowances	100% (qualifying assets)	Eligible businesses	Electric vehicle charging points
Writing Down Allowance	18% / 6%	Assets not qualifying for immediate relief	Integral features, long-life assets
Structures & Buildings Allowance	3% per year (qualifying expenditure)	Commercial property owners	Depot, warehouse, office

Important: Tax legislation and Capital Allowance rules can change. The information in this guide is based on the rules applicable at the time of writing and is intended as general guidance only.

1. What Are Capital Allowances?

Capital Allowances are a form of tax relief that allows businesses to claim the cost of certain capital assets against their taxable profits.

Unlike everyday running costs such as wages, fuel or office supplies, capital assets are items that are expected to benefit the business for more than one accounting period.

Instead of deducting the full cost as a normal business expense, the tax system provides relief through Capital Allowances.

For construction companies, these often include investments in:

• Commercial vans

• Pickup trucks (depending on their specification)

• Excavators and diggers

• Dumpers and rollers

• Scaffolding

• Power tools

• Surveying equipment

• Site cabins

• Generators

• Compressors

• Office furniture

• Computers and laptops

• Printers and IT equipment

Claiming the correct Capital Allowances ensures your business receives the tax relief it is entitled to while maintaining accurate company accounts.

A specialist construction accountant can also help determine whether purchases qualify for immediate relief or whether they should be claimed over several years.

2. Capital Expenditure vs Revenue Expenditure

One of the most common areas of confusion for construction business owners is understanding the difference between capital expenditure and revenue expenditure.

This distinction is important because the tax treatment is different.

Revenue Expenditure

Revenue expenditure relates to the day-to-day running of your business and is generally deducted as a business expense in the accounting period in which it is incurred.

Examples include:

• Fuel

• Vehicle servicing

• Office stationery

• Insurance

• Telephone bills

• Advertising

• Repairs and maintenance

• Wages

• Subcontractor costs

These costs are usually deducted directly when calculating your taxable profits.

Capital Expenditure

Capital expenditure relates to assets that are expected to provide value to the business over several years.

Examples include:

• Purchasing a new company van.

• Buying an excavator.

• Investing in scaffolding.

• Purchasing a generator.

• Buying new office furniture.

• Installing computer equipment.

• Purchasing surveying equipment.

Rather than treating these purchases as ordinary expenses, businesses may claim Capital Allowances where the expenditure qualifies.

Understanding this distinction helps ensure your accounts are prepared correctly and that available tax relief is not missed.

3. What Can Construction Companies Claim Capital Allowances On?

Construction businesses purchase a wide variety of assets, but not every purchase qualifies for the same type of tax relief.

The table below provides a general guide.

Assets That Commonly Qualify	Items That Generally Do Not Qualify
Commercial vans	Land
Excavators	Residential buildings
Diggers	Stock held for resale
Dumpers	Everyday repairs
Scaffolding	Wages
Power tools	Utility bills
Site cabins	Advertising costs
Generators	Client entertainment
Office furniture	General office expenses
Computers and laptops	Routine maintenance

Whether an asset qualifies depends on the specific circumstances and the type of relief being claimed.

Some assets may qualify for immediate relief, while others receive relief over a number of years.

For this reason, maintaining accurate construction bookkeeping and an up-to-date fixed asset register is essential.

4. Annual Investment Allowance (AIA)

For most contractors and construction companies, the Annual Investment Allowance (AIA) is the most valuable Capital Allowance available.

The AIA allows businesses to deduct 100% of the cost of qualifying plant and machinery from their taxable profits, up to the annual limit.

Current Annual Investment Allowance

Tax Relief	Current Limit
Annual Investment Allowance (AIA)	£1,000,000 per year

This means that, subject to the qualifying rules, a business can claim tax relief on up to £1 million of eligible expenditure each year rather than spreading the relief over several accounting periods.

For most small and medium-sized construction companies, this is more than enough to cover annual investment in vehicles, machinery, tools and equipment.

Example

ABC Construction Ltd purchases the following during its accounting year:

Asset Purchased	Cost
Commercial Van	£42,000
Excavator	£58,000
Scaffolding	£18,000
Power Tools	£7,500
Office Computers	£4,500

Total Investment: £130,000

As the total qualifying expenditure is well below the current £1 million Annual Investment Allowance, the company may be able to claim 100% tax relief on the qualifying assets in the year of purchase, subject to the applicable tax rules.

This can significantly reduce the company's taxable profits and improve cash flow.

For growing construction businesses investing heavily in plant and machinery, the AIA is often one of the most valuable tax reliefs available.

5. First-Year Allowances (FYAs)

While the Annual Investment Allowance (AIA) is the most common Capital Allowance used by contractors, some assets may qualify for First-Year Allowances (FYAs).

These allow businesses to claim 100% tax relief in the year of purchase on certain qualifying assets that meet specific government criteria.

Unlike the AIA, which generally applies to plant and machinery, First-Year Allowances are designed to encourage businesses to invest in environmentally beneficial technologies and energy-efficient equipment.

Depending on the type of asset purchased, qualifying expenditure may include:

• Energy-efficient equipment

• Water-efficient technologies

• Certain electric vehicle charging equipment

• Other qualifying assets approved under HMRC rules

For construction businesses investing in modern equipment, these reliefs can further reduce taxable profits while supporting more sustainable operations.

As qualifying assets change over time, it is important to confirm eligibility before making significant purchases.

6. Full Expensing

One of the most significant recent tax incentives for limited companies is Full Expensing.

This allows companies to deduct 100% of the cost of qualifying new plant and machinery from their taxable profits in the year the expenditure is incurred.

Unlike the Annual Investment Allowance, which has an annual limit, Full Expensing applies to qualifying expenditure under its own rules.

Example

A construction company purchases:

Asset	Cost
New Excavator	£95,000
New Generator	£18,000
Concrete Mixer	£12,000

Total Investment: £125,000

Provided the assets qualify, the company may be able to deduct the full cost when calculating its Corporation Tax liability, improving cash flow and reducing taxable profits.

For growing contractors investing heavily in machinery, this can represent a significant tax saving.

A specialist construction accountant can help determine whether the Annual Investment Allowance or Full Expensing provides the most appropriate relief based on the company's circumstances.

7. Writing Down Allowances (WDA)

Not every asset qualifies for immediate 100% tax relief.

Where an asset does not qualify for the Annual Investment Allowance, First-Year Allowances or Full Expensing, businesses may instead claim Writing Down Allowances (WDAs).

Rather than claiming the full cost immediately, tax relief is spread over several years.

Writing Down Allowance Rates

Pool	Rate
Main Pool	18%
Special Rate Pool	6%

The Main Pool generally includes most plant and machinery.

The Special Rate Pool typically includes assets such as:

• Certain integral features of buildings

• Thermal insulation

• Long-life assets

• Other assets specified by HMRC

Understanding which pool an asset belongs to is important, as it affects how quickly tax relief can be claimed.

8. Structures and Buildings Allowance (SBA)

Many construction companies eventually purchase their own:

• Office

• Depot

• Storage yard

• Warehouse

• Industrial unit

Unlike plant and machinery, buildings do not usually qualify for the Annual Investment Allowance.

Instead, eligible expenditure may qualify for the Structures and Buildings Allowance (SBA).

The SBA currently allows qualifying expenditure on eligible commercial structures and buildings to be relieved over time.

This means businesses receive tax relief gradually rather than immediately.

If your construction company is considering purchasing commercial premises, speaking with a contractor accountant before completing the transaction can help identify which costs qualify for tax relief.

9. Cars vs Vans – A Common Area of Confusion

One of the biggest areas of confusion for construction companies is the difference between cars and commercial vehicles.

Although they may appear similar, the tax treatment can be very different.

Commercial Vans

Commercial vans generally qualify for more generous Capital Allowances because they are treated as plant and machinery.

Examples include:

• Panel vans

• Transit vans

• Luton vans

• Commercial tippers

These vehicles commonly qualify for the Annual Investment Allowance where the qualifying conditions are met.

Company Cars

Company cars are subject to different Capital Allowance rules.

The amount of relief available depends on several factors, including the vehicle's CO₂ emissions.

Lower-emission vehicles generally receive more favourable tax treatment than higher-emission vehicles.

Double-Cab Pickups

Double-cab pickups have historically been popular within the construction industry.

However, the tax treatment of some double-cab pickups has changed in recent years.

Whether a pickup is treated as a commercial vehicle or a company car depends on the applicable tax legislation and the vehicle's classification at the relevant time.

Because these rules continue to evolve, construction businesses should seek professional advice before purchasing a pickup solely for tax reasons.

Construction Example

XYZ Electrical Contractors Ltd is considering purchasing:

Asset	Cost
Transit Van	£39,000
Double-Cab Pickup	£47,000
Excavator	£82,000
Scaffolding	£26,000
Office Computers	£6,000

Rather than focusing only on the purchase price, the company should also consider:

• Which Capital Allowances apply.

• Whether Full Expensing is available.

• Whether the Annual Investment Allowance should be used.

• The long-term tax implications.

• The business's expected taxable profits.

Planning purchases alongside your accountant can often produce a more tax-efficient outcome than making investment decisions based solely on immediate business needs.

10. Common Capital Allowance Mistakes Construction Companies Make

Capital Allowances can provide significant tax relief, but mistakes are common, particularly among growing construction businesses that purchase equipment regularly.

Below are some of the most common issues we encounter.

Claiming Repairs Instead of Capital Expenditure

One of the biggest areas of confusion is the difference between repairing an existing asset and purchasing a new one.

For example:

Expenditure	Typical Tax Treatment
Repairing an existing excavator	Revenue expense
Purchasing a new excavator	Capital expenditure
Replacing worn brake pads on a van	Revenue expense
Buying a new company van	Capital expenditure

Understanding this distinction helps ensure your accounts are prepared correctly and that the appropriate tax relief is claimed.

Failing to Keep Purchase Invoices

HMRC may request evidence to support Capital Allowance claims.

Construction companies should retain:

• Supplier invoices

• Finance agreements

• Purchase receipts

• Delivery documentation

• Asset serial numbers where appropriate

Maintaining organised records also makes preparing company accounts much more efficient.

Not Maintaining a Fixed Asset Register

Many small construction businesses buy equipment throughout the year but never record it properly.

A Fixed Asset Register helps track:

• Purchase date

• Purchase cost

• Supplier

• Asset description

• Capital Allowance claimed

• Disposal date

• Sale proceeds

Keeping this information up to date makes year-end accounting simpler and reduces the risk of missing valuable tax relief.

Purchasing Assets Personally Instead of Through the Company

Some directors purchase tools, machinery or equipment personally and later reimburse themselves.

Depending on the circumstances, this may complicate record keeping and affect the available tax relief.

Before making significant purchases, speak with your construction accountant to determine the most appropriate purchasing method.

Assuming Every Purchase Qualifies

Although many assets qualify for Capital Allowances, not everything does.

Always check before making significant investments.

A specialist contractor accountant can confirm which reliefs apply and ensure claims are made correctly.

11. Selling or Disposing of Business Assets

Capital Allowances don't only apply when purchasing assets.

They can also affect the tax position when assets are sold, scrapped or otherwise disposed of.

Examples include:

• Selling a company van.

• Trading in an excavator.

• Replacing scaffolding.

• Selling surplus machinery.

• Disposing of office equipment.

The disposal proceeds may affect future Capital Allowance calculations.

For this reason, it is important to keep accurate records throughout the life of every business asset.

12. Why Good Construction Bookkeeping Matters

Capital Allowances rely on accurate financial records.

Without reliable bookkeeping, construction businesses may:

• Miss available tax relief.

• Duplicate asset purchases.

• Lose supplier invoices.

• Record purchases incorrectly.

• Delay preparation of company accounts.

• Pay more Corporation Tax than necessary.

Good construction bookkeeping does much more than keep HMRC satisfied.

It provides directors with accurate financial information, supports investment decisions and helps maximise available tax relief.

At Vau Consult, we encourage clients to maintain their bookkeeping throughout the year rather than waiting until their year-end accounts are prepared.

13. Frequently Asked Questions

Can builders claim Capital Allowances?

Yes.

Builders, contractors and construction companies may claim Capital Allowances on qualifying plant and machinery used within their business, subject to HMRC rules.

Can electricians claim for tools?

In many cases, yes.

Power tools, testing equipment and other qualifying business assets may be eligible for Capital Allowances where they are purchased for business use.

Can I claim Capital Allowances on a company van?

Commercial vans generally qualify for Capital Allowances.

However, the exact relief available depends on the circumstances and the applicable tax rules.

Do second-hand assets qualify?

Many second-hand business assets may qualify for Capital Allowances.

The available relief depends on the specific asset and the type of allowance being claimed.

Can sole traders claim Capital Allowances?

Yes.

Capital Allowances are available to sole traders, partnerships and limited companies, provided the qualifying conditions are met.

What happens when I sell an asset?

Selling a business asset may affect your Capital Allowance position.

The tax treatment depends on factors such as:

• Sale proceeds.

• Original purchase cost.

• The type of allowance previously claimed.

• The asset pool in which it was included.

14. How Vau Consult Can Help

At Vau Consult, we specialise in construction accounting for contractors, subcontractors and growing construction businesses across the UK.

Our services include:

• Construction bookkeeping.

• Company accounts.

• Capital Allowance planning.

• CIS administration.

• VAT returns.

• Payroll.

• Management accounts.

• Cash flow forecasting.

• Fixed Asset Registers.

• Corporation Tax planning.

Whether you're investing in a new van, purchasing plant and machinery or expanding your business, we can help ensure you claim the tax relief you're entitled to while keeping your accounts accurate and compliant.

Final Thoughts

Construction businesses invest heavily in equipment, machinery and vehicles to deliver projects efficiently and remain competitive.

Understanding how Capital Allowances work can significantly reduce your Corporation Tax liability while supporting future growth.

Although the tax rules can appear complex, claiming the correct relief at the right time can improve cash flow and maximise the value of your business investments.

Because every business is different, Capital Allowances should always be considered alongside your wider tax planning, company accounts and long-term investment strategy.

Working with a specialist construction accountant ensures your purchases are recorded correctly, available reliefs are not overlooked and your business remains compliant with HMRC.