If you run a marketing, digital, or creative agency, you buy equipment. Laptops, monitors, office furniture, servers, software licences, maybe a company car. The question is: how much of that cost can you write off against your corporation tax bill in the same year?
The answer, for most agency founders, is the annual investment allowance (AIA). It lets you claim 100% tax relief on qualifying plant and machinery up to £1 million per year [1]. That means you deduct the full cost from your profits before tax is calculated. No spreading the cost over several years. No complicated calculations.
This guide covers the 2025/26 rules, what qualifies, what doesn't, and how to avoid common mistakes. If you are planning a significant equipment purchase for your agency this year, read this before you sign anything.
What Is the Annual Investment Allowance?
The AIA is a capital allowance that gives you immediate tax relief on qualifying expenditure. You claim it in the accounting period when you buy the item [1]. For most limited company agencies, that means the full cost comes off your taxable profits in the year of purchase.
The current AIA amount is £1 million [1]. This has been in place since 1 January 2019 and was originally intended as a temporary measure. It has been extended several times and remains in force for the 2025/26 tax year [2].
For a typical agency paying corporation tax at 19% or 25%, claiming the full £1 million AIA saves you between £190,000 and £250,000 in tax. That is a significant cash flow benefit.
What Equipment Qualifies for AIA?
The AIA covers most plant and machinery used in your agency. HMRC defines this broadly. It includes:
- Computers, laptops, monitors, and tablets
- Office furniture and fixtures (desks, chairs, shelving, partitions)
- Servers, networking equipment, and data storage
- Telephone systems and video conferencing equipment
- Air conditioning, heating, and ventilation systems
- Company cars (with some restrictions on CO2 emissions)
- Tools and equipment used by your team
- Certain building fixtures (solar panels, lifts, fire alarms)
Software licences are a grey area. If you buy a perpetual licence (a one-off purchase), it typically qualifies. If you pay a monthly subscription, it is revenue expenditure and you deduct it through your profit and loss account, not through capital allowances.
What Does NOT Qualify?
Some items are specifically excluded from the AIA. The main ones for agency founders are:
- Buildings and land, you cannot claim AIA on the cost of buying or constructing a building
- Cars with high CO2 emissions, cars over 50g/km CO2 do not qualify for AIA; they go into the main or special rate pools instead
- Items used partly for business, if you use a laptop 60% for business and 40% personally, you can only claim AIA on the business proportion
- Gifts and items you already owned, you cannot claim AIA on something you owned before starting your business; you use market value instead [3]
- Items bought in the final accounting period before your business closes, no AIA is available in that period [1]
How the £1 Million AIA Limit Works
The £1 million limit applies per accounting period. If your agency has a 12-month accounting period, you get the full £1 million. If your period is shorter, the limit is proportionally reduced.
For example, if your accounting period is 9 months, the AIA will be 9/12 x £1,000,000 = £750,000 [1].
If you spend more than the AIA limit in a period, the excess goes into your main pool (18% writing down allowance) or special rate pool (6% writing down allowance), depending on the asset type. You get tax relief, just spread over several years instead of immediately.
When Is the Equipment 'Bought' for AIA Purposes?
This is where many agency founders trip up. The date you buy the item is not necessarily the date you pay for it or the date it arrives. HMRC has specific rules [1]:
- If you sign a contract and payment is due within less than 4 months, the date you bought it is the date you signed the contract
- If payment is due more than 4 months later, the date you bought it is the date payment is due
- If you buy something under a hire purchase contract, you can claim AIA when you start using the item, for all payments you will make under the contract [1]
This matters for year-end planning. If you sign a contract for £50,000 of equipment on 31 March 2026 (your year-end) and payment is due within 4 months, you can claim the AIA in the 2025/26 period. If you delay signing until 2 April 2026, it falls into the next period.
Full Expensing vs AIA: What Is the Difference?
Since 1 April 2023, the government introduced full expensing for companies. This allows a 100% first-year allowance on qualifying plant and machinery, with no cap [3]. Full expensing is available to limited companies only, not to sole traders or partnerships.
So why use AIA at all? Two reasons:
- Sole traders and partnerships cannot use full expensing. AIA is their main route to immediate relief.
- Special rate assets (long-life assets, integral features, cars over 50g/km CO2) qualify for a 50% first-year allowance under full expensing, but only 6% writing down allowance in the main pool. AIA gives 100% relief on these assets up to the £1 million limit.
For most limited company agencies, full expensing is simpler and more generous than AIA for main pool assets. But AIA remains useful for special rate assets and for sole traders.
Worked Example: A Digital Agency Buying Equipment
Let us run through a realistic scenario. You run a 12-person digital agency in Manchester's Northern Quarter. Your accounting period runs 1 April 2025 to 31 March 2026. Your taxable profit before capital allowances is £400,000.
During the year, you buy:
- 12 new MacBook Pros for your team: £24,000
- 6 large monitors: £3,600
- A new server and networking equipment: £8,500
- Office furniture for a refurb: £12,000
- A Tesla Model 3 (company car, 0g/km CO2): £42,000
Total qualifying expenditure: £90,100. All of it qualifies for AIA (the Tesla is electric, so it qualifies).
You claim the full £90,100 as an AIA deduction. Your taxable profit reduces to £309,900. At 25% corporation tax (assuming profits exceed £250k), you save £22,525 in tax. That is a real cash saving.
If you had not claimed AIA, the equipment would go into your main pool at 18% writing down allowance. You would get £16,218 relief in year one, not £90,100. The difference is significant.
How to Claim the AIA
You claim the AIA on your corporation tax return (CT600) or self-assessment tax return (SA100 for sole traders). Your accountant will include the capital allowance calculation in the tax computation.
You need to keep records of:
- Invoices and receipts for each item
- Contracts and delivery notes
- Hire purchase agreements (if applicable)
- Details of any private use (if you use equipment partly for personal purposes)
Most accounting software like Xero, QuickBooks, or FreeAgent can track fixed assets and calculate capital allowances. But the AIA claim itself is typically handled by your accountant in the year-end tax return.
Common Mistakes Agency Founders Make
Mistake 1: Claiming AIA on revenue expenditure. If you lease equipment or pay a monthly subscription for software, it is revenue, not capital. You deduct it through your P&L, not through capital allowances.
Mistake 2: Missing the year-end deadline. If you sign a contract in one period but the equipment arrives in the next, check the payment terms. If payment is due within 4 months, the contract date is the purchase date [1].
Mistake 3: Forgetting the private use adjustment. If you buy a laptop you use 70% for business and 30% for personal, you can only claim AIA on 70% of the cost. HMRC will adjust this on enquiry.
Mistake 4: Assuming all cars qualify. Cars with CO2 emissions over 50g/km do not qualify for AIA. They go into the main pool (18% WDA) or special rate pool (6% WDA). Electric cars (0g/km) qualify fully.
Mistake 5: Not planning purchases across accounting periods. If you are close to the £1 million limit, consider timing your purchases to maximise relief across two periods.
Planning Your Agency Equipment Purchases
Business investment accounts for around 10% of GDP in the UK [4]. For agency founders, equipment purchases are a normal part of growth. The AIA makes them more tax-efficient.
If you are planning a significant equipment spend in 2025/26, here is a simple checklist:
- Confirm the items qualify as plant and machinery
- Check your accounting period dates
- Calculate your available AIA (full £1m for a 12-month period)
- Decide whether full expensing or AIA is better for your situation
- Keep all invoices and contracts
- Tell your accountant before year-end, not after
If you are a sole trader or partnership using the cash basis, you can only claim capital allowances on business cars [3]. Other equipment is deducted as revenue expenditure under the cash basis rules. Check with your accountant if you use cash basis accounting.
What Happens If Your Agency Closes?
If your business closes, you cannot claim AIA for items bought in the final accounting period [1]. This is a strict rule. If you know your agency is winding down, plan your equipment purchases carefully. Buy what you need before the final period starts.
Next Steps
The annual investment allowance is a straightforward relief that saves agency founders real money. If you are buying equipment this year, make sure you claim it. The rules are generous, but they have specific timing requirements. Get the date wrong and you lose the relief for that period.
If you want to discuss your agency's equipment plans and how to structure purchases for maximum tax efficiency, get in touch. Our ICAEW qualified team works exclusively with agency founders and knows the capital allowance rules inside out.
For more on agency tax planning, read our tax and compliance blog or see how we help digital agencies manage their finances.
Sources
- gov.uk: Claim capital allowances: Annual investment allowance - GOV.UK
- icaew.com: Capital allowances | Tax - ICAEW.com
- aka.hmrc.gov.uk: Claim capital allowances: Overview - GOV.UK
- bankofengland.co.uk: Influences on investment by UK businesses: evidence from the...