The Annual Investment Allowance (AIA) is a capital allowance that lets UK businesses claim 100% tax relief on qualifying plant and machinery costs in the year of purchase. For property landlords, this can be a valuable relief, but the rules differ depending on whether you own property personally or through a limited company.
This guide explains how the AIA capital allowance works for UK property landlords, what qualifies, and what doesn't. We cover the current £1 million limit, how it applies to partnerships and companies, and what happens when you sell an asset you've claimed AIA on.
What Is the Annual Investment Allowance (AIA)?
The AIA is a form of capital allowance that gives you 100% tax relief on qualifying plant and machinery costs up to a set annual limit. You deduct the full cost from your taxable profits in the period you buy the item [1].
For most businesses, the current AIA amount is £1 million. This applies to sole traders, partnerships, and limited companies [1]. The £1 million limit has been in place since 1 January 2019 [1].
If your accounting period is shorter than 12 months, the AIA 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].
Can Property Landlords Claim the AIA?
Whether you can claim the AIA capital allowance depends on how you hold your property. The key distinction is between a property investment business and a property trading business.
Personal Landlords (Individual Ownership)
If you own rental property personally as an individual landlord, you are running a property investment business. In most cases, you cannot claim capital allowances on residential property because the plant and machinery in a dwelling house does not qualify. This includes items like boilers, kitchens, and bathrooms in standard buy-to-let properties.
However, if you own a furnished holiday let (FHL), note the FHL regime was abolished from April 2025, or commercial property, you may be able to claim capital allowances on qualifying plant and machinery. The rules changed significantly from April 2025, so you should check your specific situation.
If you use the cash basis for your rental business, you can only claim capital allowances on business cars [2]. Most individual landlords use the accruals basis, so this restriction may not apply.
Limited Companies
If you hold property through a limited company (often called a Special Purpose Vehicle or SPV), the company can claim the AIA capital allowance on qualifying plant and machinery used in its property business. This is more common for commercial property portfolios or large-scale residential developments.
For companies, the AIA works alongside other capital allowance reliefs. From 1 April 2023, full expensing and 50% first-year allowance can be claimed on qualifying plant and machinery investments [2]. The super-deduction and 50% special rate first-year allowance applied to assets bought from 1 April 2021 to 31 March 2023 [2].
If you are considering incorporating your property portfolio, our incorporation guide explains the tax implications.
What Qualifies for the AIA?
To qualify for the AIA capital allowance, the item must be plant and machinery as defined by HMRC. This typically includes:
- Equipment and machinery used in the property business
- Fixtures in commercial properties (e.g., heating systems, air conditioning, lifts)
- Office equipment and furniture for your property management business
- Business cars (subject to certain restrictions)
- Computer hardware and software used for property management
You can only claim AIA in the period you bought the item [1]. The item must be owned by the business, but it does not have to have been paid for yet. The AIA may be claimed on equipment purchased through a hire purchase (HP) agreement or a loan, but not through a leasing agreement [3].
What Does NOT Qualify for the AIA?
Several types of expenditure do not qualify for the AIA capital allowance:
- Buildings and land (unless integral features)
- Cars (generally excluded from AIA, though some business cars may qualify for writing down allowances)
- Items used partly for business and partly for private use (the business proportion may qualify)
- Gifts and entertainment
- Items bought in the final accounting period before your business closes [1]
How the AIA Works for Partnerships
For partnerships, the AIA capital allowance is available to each individual partner in respect of their share of the partnership's qualifying expenditure [4]. The AIA limit for a partnership is the same as for a company, £1 million for qualifying expenditure incurred between 1 January 2019 and 31 December 2020 [4].
HMRC clarified that each partner can claim their share of the AIA, subject to the overall partnership limit [4]. This is important for property partnerships where multiple partners invest in plant and machinery.
AIA and Limited Companies: Group Rules
If two or more limited companies are controlled by the same person, they only get one AIA between them [1]. This means you cannot split your property portfolio across multiple companies to claim multiple AIA allowances. The group must share the £1 million limit.
This rule prevents businesses from artificially dividing their operations to claim multiple allowances. If you are considering restructuring your property portfolio, speak to a specialist property accountant to understand the implications.
Writing Down Allowances: What Happens After the AIA
If you spend more than the AIA limit in a period, or if you buy assets that do not qualify for the AIA, you can claim writing down allowances (WDAs) instead. WDAs let you claim a percentage of the remaining value each year [2].
The main rate for WDAs is 18% per year on a reducing balance basis. Special rate assets (like integral features in buildings) qualify for 6% per year. You can claim WDAs if plant and machinery does not qualify for another allowance, or if there is value remaining after claiming the maximum amount of another allowance [2].
AIA and Disposals: What Happens When You Sell
When you sell an asset on which you have claimed the AIA capital allowance, you must account for the disposal. The proceeds are deducted from the pool of qualifying expenditure. If the proceeds exceed the remaining pool value, a balancing charge arises, which is added to your taxable profits.
This is a common issue for property landlords who sell a property with fixtures on which they have claimed capital allowances. The disposal proceeds must be allocated between the property and the fixtures.
Practical Example: AIA for a Property Company
Consider a property company that owns a portfolio of commercial properties. In the 2025/26 accounting period, the company spends £800,000 on new heating systems, lifts, and air conditioning units across its properties. All of these items qualify as plant and machinery.
The company can claim the full £800,000 as an AIA capital allowance in that period, reducing its taxable profits by £800,000. If the company had spent £1.2 million, it could claim £1 million under the AIA and the remaining £200,000 would attract writing down allowances at 18% per year.
AIA and Making Tax Digital (MTD)
From 6 April 2026, Making Tax Digital for Income Tax becomes mandatory for landlords with gross property income over £50,000 [source: MTD rules]. The threshold drops to £30,000 from April 2027 and £20,000 from April 2028.
If you are claiming the AIA capital allowance, you need to keep accurate digital records of your qualifying expenditure. Our MTD guide for landlords explains the requirements.
Common Mistakes with AIA Claims
Several common mistakes arise when landlords claim the AIA capital allowance:
- Claiming AIA on residential property fixtures that do not qualify
- Forgetting to apportion the AIA limit for short accounting periods
- Claiming AIA on leased assets (only HP and loan-financed assets qualify) [3]
- Not accounting for disposals correctly
- Failing to consider group company rules [1]
If you are unsure about your claim, our property accountant services can help you review your capital allowance position.
Should You Claim the AIA?
The AIA capital allowance is a valuable relief for property businesses that invest in qualifying plant and machinery. However, it is not always the best option. In some cases, you may prefer to spread the relief over several years using writing down allowances, particularly if you have low profits in the current year.
You should also consider the interaction with other reliefs, such as full expensing for companies. Full expensing and 50% first-year allowance can be claimed on qualifying plant and machinery investments from 1 April 2023 [2].
For most property landlords, the AIA is most relevant if you own commercial property through a limited company. If you own residential property personally, your ability to claim capital allowances is limited.
How a Property Accountant Can Help
Claiming the AIA capital allowance correctly requires a good understanding of the rules. A specialist property accountant can help you identify qualifying expenditure, calculate the correct relief, and ensure you comply with HMRC requirements.
If you are considering incorporating your property portfolio, our guide to buy-to-let limited companies explains the tax implications. For a full overview of property tax, see our property investment tax guide.
To discuss your specific situation, contact our team for a consultation.