Computer peripherals

Conditions

• Computer peripherals — monitors, keyboards, mice, docking stations, webcams, headsets, and similar items kept for use in the business — are plant and machinery for capital-allowances purposes. They qualify for the Annual Investment Allowance (AIA), giving 100% relief in the year of purchase up to £1 million per accounting period (verified GOV.UK June 2026 — re-check after each Budget). From April 2026, a 40% first-year allowance applies to qualifying new main-rate plant and machinery where spending exceeds the AIA; the main-pool writing-down rate reduces to 14% (from 18%). For most small businesses, the AIA gives full relief in the year of purchase.
• Under the cash basis — the default for most unincorporated businesses from 2024/25 — peripherals are claimed directly as allowable business expenses rather than through capital allowances.
• Very low-cost, short-lived items — such as a mouse or basic keyboard costing a few pounds — may in practice be treated as revenue running costs rather than capital items, particularly if replaced frequently. Higher-value durable peripherals (a large monitor, a quality headset used daily) are capital items and should go through capital allowances under traditional accounting.
• Where peripherals are also used personally — for example, a monitor at home used in the evenings for personal activity, or a headset also used for personal calls — only the business proportion is allowable. Keep a brief note of how the split was determined.
• For a limited company, peripherals purchased by the company for business use are company assets and the costs are allowable deductions.
• Employees can claim capital allowances on peripherals necessarily required for the performance of their duties, where there is no significant private use and the employer has not provided the item. This mirrors the conditions that apply to laptops and other equipment under EIM36500.

Common mistakes

• Claiming 100% of the cost of a peripheral kept at home where there is also personal use.
• Under traditional accounting, treating a substantial monitor or docking station as a day-to-day running expense rather than a capital item.
• An employee claiming peripherals where the employer would have supplied them on request, or where significant personal use exists.

What to keep

• Purchase invoices or receipts showing the peripheral, date, and cost.
• A note of the business-use proportion for any item also used privately.

Real-world example

A sole trader working from home on traditional accounting buys a 32-inch monitor (£620), a mechanical keyboard (£85), and a webcam (£90) used entirely for business. The total £795 is claimed under the Annual Investment Allowance in the year of purchase. She separately buys a replacement USB cable costing £8 — this is treated as a negligible running cost.

Frequently asked

Related allowances