# Annual Investment Allowance Guide 2026: Claiming Your £1m Limit

The UK Annual Investment Allowance provides immediate 100% tax relief on qualifying capital assets up to a £1 million limit. This 2026 guide covers eligibility, qualifying plant and machinery, and transition rules.

**Published:** 2026-07-03  
**Updated:** 2026-07-05  
**Source:** https://aztajournal.com/gb/annual-investment-allowance-guide-2026

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> The UK Annual Investment Allowance provides immediate tax relief on qualifying business assets. This 2026 guide explains the permanent £1 million annual threshold, corporate and individual eligibility rules, and crucial capital allowance rate transitions taking effect from April 2026.

The **Annual Investment Allowance** (AIA) is a UK capital allowance that lets your business deduct the full cost of qualifying plant and machinery up to a specified limit from your taxable profits in the tax year of purchase. Under UK tax law, you can claim the full £1 million allowance on equipment within a single accounting period, meaning you do not have to spread the tax deduction over multiple years.

## Key Takeaways: AIA Rules and Limits for 2026

These key rules govern how businesses must apply the Annual Investment Allowance to their capital purchases in 2026:

1. The AIA limit is permanently set at £1 million per qualifying 12-month accounting period.
2. AIA provides a 100% tax deduction in the year of purchase rather than spreading relief over time.
3. The allowance is available to sole traders, partnerships with individual members, and limited companies.
4. Unlike Full Expensing, the AIA can be claimed on both brand new and used (second-hand) machinery.
5. Exclusions apply to specific asset classes, meaning cars and assets used for non-business purposes do not qualify for the full allowance.

## What is the Annual Investment Allowance and can I claim the full £1 million on equipment?

The **Annual Investment Allowance** is a 100% first-year tax deduction established under section 51A of the **Capital Allowances Act 2001** (CAA 2001) that allows UK businesses to write off the entire cost of qualifying capital purchases up to a £1 million limit in the year of acquisition.

Under the **Capital Allowances Act 2001**, the £1 million limit has been legislated as a permanent allowance since 1 January 2019. Any business that incurs qualifying capital expenditure of £1 million or less within its standard 12-month accounting period can claim the full amount as an immediate deduction against its taxable profits, reducing its overall tax liability for that year.

## Who is eligible to claim the AIA?

Under section 38A of the **Capital Allowances Act 2001**, only "qualifying persons" are eligible to claim the AIA.

To claim this allowance, your business entity must fall into one of the following legal categories, with no restrictions placed on the size of your business:

- **Individuals** operating as sole traders.
- **Partnerships** where every single member of the partnership is an individual.
- **Limited companies** registered in the UK.

Mixed partnerships that contain corporate members or other partnerships as partners do not meet the definition of a qualifying person and cannot claim the allowance.

## What plant and machinery qualifies for AIA in 2026?

Most capital assets used for business operations qualify as plant and machinery for AIA purposes.

The AIA offers a broader scope of relief than corporate Full Expensing because it covers both brand new and pre-owned items. The following items qualify for the allowance:

- Manufacturing and industrial processing equipment.
- Information technology systems, office computers, and servers.
- Commercial machinery, specialized tools, and replacement parts.
- Office furniture, fittings, and business furnishings.
- Commercial refrigeration units and warehouse storage systems.
- Used or second-hand assets purchased for business use.

## What assets do not qualify for the AIA?

Certain types of capital expenditure are explicitly excluded from the AIA under UK tax legislation.

When planning your capital purchases, you must exclude the following assets from your AIA claims:

1. **Cars:** Passenger vehicles are categorically excluded from the AIA, though they may qualify for standard Writing Down Allowances or specific First Year Allowances.
2. **Assets with private or non-business use:** If you are a sole trader or partner and use an asset partially outside your business, you must reduce your AIA claim proportionally.
3. **Ring-fence trade expenditure:** Capital spending related to North Sea oil and gas extraction trades must be excluded.
4. **Final trading periods:** You cannot claim the AIA on capital goods purchased in the final chargeable accounting period in which you permanently stop trading.

## How does the £1 million limit change under different conditions?

The £1 million AIA limit is adjusted depending on the length of your accounting period and relationships between business entities.

Section 51A(6) of the **Capital Allowances Act 2001** dictates how the allowance must be proportioned or divided under specific business conditions. The table below details these adjustments:

| Business Condition | AIA Limit Impact | Tax Treatment of Excess Spend |
| --- | --- | --- |
| Standard 12-Month Period (spend ≤ £1m) | Full £1 million allowance remains available. | 100% immediate deduction of capital asset cost. |
| Short Accounting Period (under 12 months) | The £1 million limit is reduced proportionally. | Excess spend above the reduced limit goes to standard pools. |
| Related Businesses under Common Control | A single £1 million allowance must be shared between entities. | Purchases above the shared allocation must use pool allowances. |
| Spend exceeding £1 million | The £1 million limit is fully exhausted. | Excess spending is written down over time in the main pool. |

## What happens to capital expenditure above £1 million?

Capital expenditure that exceeds the £1 million cap is allocated to capital allowance pools where it is written down over time.

Any qualifying spend above the £1 million limit enters the main pool. From April 2026, this excess spend attracts a standard **Writing Down Allowance (WDA)** rate of 14% per year on a reducing balance basis.

For incorporated businesses, alternative options exist for managing excess expenditure. Companies can utilize **Full Expensing** on qualifying new, unused main-rate assets, which offers a 100% deduction with no upper monetary cap. Additionally, a **40% First Year Allowance** is available for eligible company purchases.

## How do the April 2026 capital allowance changes affect my business?

Transition rules in 2026 alter the rates of relief for capital expenditure made by UK businesses.

To optimize tax planning, you should prepare for the following statutory adjustments implemented in 2026:

- The main pool Writing Down Allowance rate decreases from **18% to 14%** starting in April 2026.
- A new **40% First Year Allowance** took effect on 1 January 2026, applying to qualifying plant and machinery assets.
- The 40% First Year Allowance is accessible to both companies and unincorporated businesses, and crucially extends to leased assets which are excluded from Full Expensing.

### Can you claim both the AIA and Full Expensing in 2026?

Yes. Corporate entities can claim both allowances in the same year. Businesses often offset their first £1 million of capital expenditure on used or special-rate assets using the AIA, and then use Full Expensing for unlimited qualifying brand-new main-rate assets to maximize tax relief.

### Can I claim the Annual Investment Allowance on used or second-hand equipment?

Yes. Unlike Full Expensing, which is strictly limited to new and unused items, the AIA allows you to claim the full 100% tax deduction on qualifying second-hand or pre-owned plant and machinery up to the £1 million limit.

### How does a short accounting period affect my £1 million AIA limit?

Under section 51A(6) of the Capital Allowances Act 2001, your AIA limit is reduced proportionally. For example, if your accounting period lasts nine months instead of twelve, your maximum AIA limit for that period is restricted to £750,000.

### Are cars eligible under the Annual Investment Allowance in the UK?

No. Cars are explicitly excluded from the AIA, even if they are used solely for business purposes. Instead, businesses must claim capital relief on vehicles through specific First Year Allowances or standard Writing Down Allowances.