Capital Allowances for Small Businesses UK 2026/27 -- AIA GBP 1m, Writing Down and First Year Allowances

What Are Capital Allowances and Why Do They Matter?

When a business buys a physical asset -- a machine, a van, a computer -- the cost is capital expenditure, not a day-to-day expense. Accounting rules spread this cost over the asset's useful life through depreciation. But depreciation is not tax-deductible. Instead, HMRC provides capital allowances: a parallel system that gives tax relief on capital spending, often more quickly than accounting depreciation would.

The practical effect is significant. A sole trader who spends GBP 50,000 on new machinery in 2026/27 can claim a GBP 50,000 AIA deduction -- reducing taxable profit by GBP 50,000 in that same year. At the higher rate of 40%, that saves GBP 20,000 in income tax. Without capital allowances, the trader would only deduct, say, GBP 10,000 of depreciation per year -- and even that would not be tax-deductible. Capital allowances are therefore one of the most important tax reliefs available to any business with physical assets.

Annual Investment Allowance -- GBP 1,000,000 100% Relief

The Annual Investment Allowance (AIA) is the cornerstone of UK capital allowances for small and medium businesses. Key facts:

• Limit: GBP 1,000,000 per year -- permanent since April 2023.
• Rate: 100% in the year of purchase. No waiting, no spreading over years.
• Who qualifies: sole traders, partnerships, limited companies -- all can claim AIA.
• What qualifies: most plant and machinery (see below), but NOT cars and NOT assets used for leasing to third parties.
• Short accounting periods: if your accounting period is less than 12 months, the GBP 1m limit is scaled down proportionately. A 9-month period = GBP 750,000 AIA.
• Groups and connected businesses: associated businesses (under common control) share a single GBP 1m AIA limit -- they do not each get GBP 1m.

For almost every small business in the UK, the GBP 1m cap is more than adequate. Most sole traders and SMEs spend well under GBP 1m on plant and machinery in a year, so AIA gives them instant 100% relief on all qualifying capital expenditure.

Writing Down Allowance -- Main Pool 18% and Special Rate Pool 6%

When expenditure exceeds the AIA cap, or when assets are excluded from AIA (like cars), the Writing Down Allowance (WDA) applies. WDA is a reducing balance allowance -- each year you deduct a percentage of the pool balance, and the remainder carries forward.

Main pool (18% WDA): Most plant and machinery that does not qualify for AIA or FYA, and low-emission cars (1-50g CO2), enters the main pool. The 18% WDA is calculated on the closing pool value each year.

Special rate pool (6% WDA): Certain slower-depreciation assets attract a lower 6% rate. These include:

• Integral features of buildings: heating systems, cooling systems, electrical distribution, lighting systems, lifts, escalators, moving walkways, hot and cold water systems, solar panels.
• Long-life assets: assets with an expected economic life exceeding 25 years (industrial machinery, plant in some sectors).
• Higher-emission cars (51g CO2 and above): these go into the special rate pool at 6% WDA -- very slow relief.
• Thermal insulation of buildings (for existing buildings).

First Year Allowances -- 100% Relief on Priority Assets

First Year Allowances (FYA) provide 100% tax relief in the year of purchase for specific assets that government policy encourages businesses to adopt. Unlike AIA, FYA can apply to assets excluded from AIA -- most importantly, zero-emission cars.

Zero-emission cars (100% FYA): brand-new zero-CO2-emission cars (pure electric vehicles) purchased new qualify for a 100% FYA. This means a business buying a GBP 45,000 electric car can deduct the full GBP 45,000 from taxable profits in the year of purchase. The FYA applies to both companies and unincorporated businesses (subject to the private use restriction for sole traders). Second-hand electric cars do NOT qualify for FYA -- they enter the main pool at 18% WDA.

Electric vehicle charge points (100% FYA): new commercial EV charge points installed for use in the business qualify for 100% FYA. This relief was extended and applies through to April 2026 at least -- check gov.uk for the current end date.

What FYA does not cover: second-hand assets (most FYAs require new assets), assets acquired from connected parties, assets used primarily for leasing, or assets where the business is connected to the seller.

Cars -- A Special Capital Allowances Regime

Cars are excluded from AIA entirely. They have their own capital allowances regime based on CO2 emissions:

The message is clear: buying a high-emission company car in 2026/27 is extremely tax-inefficient. A GBP 30,000 petrol car at 120g CO2 entering the special rate pool at 6% WDA gives only GBP 1,800 relief in year one -- versus GBP 30,000 immediate relief for a zero-emission equivalent under 100% FYA. Over the life of a 4-year ownership cycle, the difference in cumulative tax relief is dramatic.

Small Pool Allowance -- Clearing GBP 1,000 Balances

The reducing-balance WDA means pools never mathematically reach zero -- they just get smaller each year. The small pool allowance (small pools election) solves this by letting you write off the entire pool balance when it falls to GBP 1,000 or below.

How it works: at the end of an accounting period, if the main pool or special rate pool balance (before WDA) is GBP 1,000 or less, you can claim the full remaining balance as a deduction instead of the normal WDA. The pool is cleared to zero.

Example: main pool balance at year-end GBP 740 (after disposals). Instead of claiming 18% WDA = GBP 133, you elect to claim GBP 740 -- the pool closes. This saves years of shrinking deductions and administration.

The small pool allowance applies separately to each pool. You could clear a GBP 800 special rate pool while continuing to claim WDA on a larger main pool. For sole traders with single-asset pools (cars with private use), the GBP 1,000 threshold applies to each single-asset pool individually.

What Qualifies -- and What Does Not

Understanding the boundary between qualifying plant and machinery and non-qualifying expenditure is essential:

QUALIFIES for AIA / WDA / FYA:

• Machinery and equipment: lathes, presses, printing machines, manufacturing plant
• IT equipment: computers, servers, networking hardware, phones, tablets
• Office furniture: desks, chairs, shelving, storage units
• Commercial vehicles: vans, lorries, forklifts, tractors (not cars)
• Tools and trade equipment
• Refrigeration and cooling equipment
• Security systems and CCTV
• Integral building features (special rate pool): heating, cooling, electrical, lighting, lifts, water systems, solar panels
• Software (where treated as plant)

DOES NOT QUALIFY for capital allowances (plant and machinery):

• Land (no depreciation, no allowance)
• Buildings and structures (only Structures and Buildings Allowance at 3%/year applies separately)
• Financial investments: shares, bonds, loans
• Stock-in-trade and work in progress
• Goodwill and other intangibles (separate intangibles regime applies)
• Assets acquired primarily for leasing to third parties (excluded from AIA)
• Expenditure on assets that have no business use

Repairs vs capital: day-to-day maintenance and repairs are revenue expenses -- deductible in full immediately -- and not capital expenditure. Replacing a like-for-like component to restore an asset to working order is typically a repair. Improving or upgrading an asset is capital expenditure qualifying for capital allowances.

Super-Deduction Abolished -- What Replaced It

The 130% super-deduction was available to companies (not sole traders or partnerships) on qualifying new main-pool plant and machinery purchased between 1 April 2021 and 31 March 2023. It provided a first-year deduction of 130% of the cost -- meaning a GBP 100,000 purchase generated a GBP 130,000 deduction, saving Corporation Tax of GBP 24,700 at the then-19% rate.

Abolished 1 April 2023. No super-deduction is available for any expenditure from that date.

Replacement -- Full Expensing (companies only):from 1 April 2023, companies can claim full expensing -- 100% first-year relief on new qualifying main-pool plant and machinery with no cap (unlike AIA which is capped at GBP 1m). A 50% first-year allowance applies to new special rate pool assets. Full expensing was made permanent in Autumn 2023. For companies spending over GBP 1m on qualifying assets, full expensing provides 100% relief on the excess above the AIA limit.

For most small businesses: the abolition of the super-deduction has little practical impact. If your capital spending is under GBP 1m per year -- which applies to the vast majority of UK SMEs -- the AIA already gives 100% immediate relief. The super-deduction was primarily relevant to large companies with very high capital expenditure.

Capital Allowances and Financing -- HP, Leasing, and Cash

The method of financing a capital purchase affects when and whether you can claim capital allowances:

• Cash purchase: straightforward. The full cost qualifies for AIA, WDA or FYA in the accounting period of purchase. Timing: allowances are generally available when the expenditure is incurred (i.e., when you become legally obliged to pay).
• Hire purchase (HP): you are treated as the owner from the date the HP agreement starts. Capital allowances are available immediately on the full purchase price -- not just the deposit paid. This is a major advantage: you can claim AIA on a GBP 50,000 machine from day one even if you are paying over 4 years. Interest charges on HP are a separate revenue deduction.
• Finance lease: where the lessee has substantially all the risks and rewards of ownership (finance lease under accounting standards), the lessee may claim capital allowances. The determination depends on the specific lease terms. Tax and accounting treatment can diverge.
• Operating lease: the lessee does NOT claim capital allowances. The lessor owns the asset and claims the allowances. The lessee deducts the lease payments as a revenue expense. For cars on operating leases with CO2 above 50g, 15% of the lease payments are disallowed.

Practical implication: if cash flow requires financing, HP is generally more tax-efficient than an operating lease for assets that would otherwise qualify for AIA -- you get the full immediate deduction without waiting to pay off the loan.

Interaction with Corporation Tax and Income Tax Rates

The value of capital allowances depends on your tax rate. For 2026/27:

• Sole traders (basic rate, 20%): GBP 1 of capital allowances saves 20p in tax.
• Sole traders (higher rate, 40%): GBP 1 saves 40p. In the personal allowance taper zone (income GBP 100,000 to GBP 125,140), GBP 1 of allowances saves up to 60p.
• Companies (small profits, 19% CT): profits up to GBP 50,000. GBP 1 saves 19p.
• Companies (main rate, 25% CT): profits above GBP 250,000. GBP 1 saves 25p.
• Companies (marginal relief): profits GBP 50,001 to GBP 250,000 face an effective marginal CT rate of 26.5% -- so GBP 1 of allowances can save 26.5p.

Timing matters too. A deduction in a year when profits are high (and the marginal rate is higher) is worth more than the same deduction in a low-profit year. If you expect profits to rise, it may be worth deferring some capital purchases to the higher- profit year, or planning AIA claims to maximise relief at the higher marginal rate. Similarly, for companies straddling the GBP 50,000 to GBP 250,000 marginal relief band, the effective rate of 26.5% makes capital allowances particularly valuable.