Writing Off Equipment: Section 179 and Capital Allowances
When you buy a van, a laptop, a coffee machine or a workshop full of tools, the cost does not always come off your taxable profit the way an ordinary bill does. Writing off equipment follows its own rules. In the US, Section 179 can let you deduct the full cost in the first year. In the UK, capital allowances such as the Annual Investment Allowance and full expensing do a similar job. This explainer shows how both work in plain language.
Key takeaways
- Equipment that lasts more than a year is usually treated as an asset, not an everyday expense, so special rules decide when you can deduct it.
- US Section 179 lets businesses deduct the full cost of qualifying equipment in the year it is placed in service, up to an annual limit you should check each year.
- In the UK, the Annual Investment Allowance gives 100% relief on qualifying plant and machinery up to £1 million a year, and companies can also use full expensing for qualifying main-rate assets.
- A full write-off lowers this year's tax, but it is not free money. Buy equipment because the business needs it, then claim the relief correctly.
Late winter is when many owners sit down with their accountant, look back at last year and plan the next round of purchases. It is also when the same question keeps coming up: "If I buy this now, can I write it off?" The honest answer is often "probably, but it depends." Knowing the basics helps you ask better questions and avoid expensive surprises.
Please read this as general information, not tax advice. Rules, limits and eligibility change, and the right approach depends on your country, structure and profits. Check the current guidance from the IRS or HMRC and talk to a qualified accountant before you rely on any relief.
Why equipment is treated differently from other costs
Most running costs, like rent, phone bills and office supplies, are used up quickly. Tax systems generally let you deduct them in the year you pay them. Equipment is different. A delivery van or a commercial oven keeps working for years, so the default approach in many tax systems is to spread its cost over its useful life rather than taking it all at once.
In accounting, that spreading is called depreciation. For tax, the US uses its own depreciation rules and the UK uses capital allowances instead of accounting depreciation. The reliefs in this article are ways to speed things up, letting you claim much or all of the cost in the first year.
What usually counts as equipment
- Machinery and tools: workshop equipment, kitchen equipment, production machines.
- Computers and tech: laptops, servers, printers, point of sale hardware.
- Furniture and fittings: desks, shelving, display units.
- Vehicles: vans and trucks often qualify, but cars usually follow special rules in both countries.
Land and buildings generally sit outside these reliefs, and some items, such as certain property improvements, have their own rules. When in doubt, ask before you buy.
How Section 179 works in the US
Section 179 of the US tax code lets a business choose to deduct the full cost of qualifying equipment in the year it is placed in service, instead of depreciating it over several years. The word "choose" matters: it is an election you make on your tax return, not something that happens automatically.
The key conditions
- Placed in service: the equipment must be ready and available for use in your business during the tax year. Buying it in December and leaving it in a box until February may move the deduction to the next year.
- Business use: the asset generally needs to be used mostly for business. Mixed-use items, like a laptop you also use personally, need careful records of the business share.
- Annual limit: there is a maximum amount you can deduct each year, and the deduction starts to phase out once total equipment purchases pass a threshold. Both figures can change, so check the current IRS numbers.
- Income limit: the deduction is generally limited to your business taxable income for the year. Any unused amount may be carried forward.
The US also has other first-year depreciation options, such as bonus depreciation, which can interact with Section 179. Which one to use, or whether to use either, is a good conversation to have with your tax preparer.
Common mistake
Buying equipment in a rush at year end just to save tax. A deduction only reduces tax on the amount you spend, so you still part with more cash than you save. If the business did not need the item, the tax relief does not make it a good purchase.
How capital allowances work in the UK
In the UK, you cannot deduct accounting depreciation for tax. Instead, you claim capital allowances on qualifying plant and machinery. The two most useful ones for small businesses are the Annual Investment Allowance and, for companies, full expensing.
Annual Investment Allowance (AIA)
The AIA gives 100% relief on qualifying plant and machinery up to £1 million a year. For most small businesses, that limit is far above what they spend, so in practice the full cost of qualifying equipment can come off taxable profits in the year of purchase. Sole traders, partnerships and limited companies can all use the AIA. Cars are generally excluded and have their own allowance rules.
Full expensing for companies
Limited companies can also use full expensing, which gives a 100% first-year deduction for qualifying main-rate plant and machinery. Because it has no fixed annual cap, it mainly matters for larger investments beyond the AIA. Special rules apply when you later sell an asset you fully expensed, so keep good records.
Writing down allowances
Anything that does not get full relief up front, such as spending above the limits or items that do not qualify, usually goes into a pool and is claimed gradually through writing down allowances. The rates differ between the main pool and the special rate pool. Check GOV.UK for the current rates.
UK Annual Investment Allowance
100% relief on qualifying plant and machinery up to £1 million a year.
Source: HMRC guidance on capital allowances, GOV.UK. Check current rules.
US and UK side by side
The two systems use different words but follow a similar idea: give businesses faster relief when they invest in equipment. Here is a quick comparison.
| US Section 179 | UK AIA | UK full expensing | |
|---|---|---|---|
| Who can use it | Businesses that elect it on their return | Sole traders, partnerships and companies | Companies only |
| How much relief | Full cost in year one, up to an annual limit | 100% up to £1 million a year | 100% on qualifying main-rate assets |
| When it applies | Year the asset is placed in service | Accounting period of purchase | Accounting period of purchase |
| Watch out for | Phase-out, income limit, business use share | Cars excluded, shared limit for related businesses | Rules on later disposal |
A simple process for claiming equipment write-offs
You do not need to become a tax expert to claim these reliefs well. You need good records and a clear routine.
- Plan the purchase. Decide what you need and why. Note the expected cost and when you will start using it.
- Check eligibility. Ask your accountant whether the item qualifies and which relief fits, especially for vehicles and mixed-use items.
- Keep the paperwork. Save the invoice, payment proof and any finance agreement in one folder.
- Record the in-service date. Write down when the equipment was installed or first used.
- Log business use. For mixed-use assets, track the business share with a simple diary or usage log.
- Add it to your asset register. Record cost, date, relief claimed and where the item is.
- Note disposals. When you sell, scrap or give away the item, record the date and amount received, since this can affect tax.
Equipment asset register template
Copy this into a spreadsheet and add one row per item. The amounts below are made-up examples.
| Item | Purchase date | In-service date | Cost | Business use | Relief claimed | Disposal |
|---|---|---|---|---|---|---|
| Laser printer | 2027-01-12 | 2027-01-14 | $600 (example) | 100% | Section 179 | None |
| Commercial oven | 2027-02-03 | 2027-02-20 | £4,500 (example) | 100% | AIA | None |
| Laptop | 2026-11-05 | 2026-11-05 | $1,400 (example) | 80% | Ask accountant | None |
Example
Imagine Aisha, who runs a small bakery in Leeds as a limited company. She buys a new mixer and a display fridge for a combined £9,000 (a made-up figure). Both are plant and machinery used only in the business, and her total spending for the year is well under the AIA limit. Her accountant claims the AIA, so the full £9,000 reduces the company's taxable profit for that year instead of being spread out. Aisha keeps the invoices and records the purchase dates in her asset register. If she sells the mixer later, her accountant will account for the sale proceeds.
Pro tip
Talk to your accountant before a big purchase, not after. Timing, financing and the type of asset can all change which relief applies, and a five-minute question can prevent a costly mistake.
Is a full write-off always the best choice?
Taking the whole deduction in year one sounds like an obvious win, and often it is. But there are times when spreading the relief makes more sense:
- Low profit this year: if your profits are small or you made a loss, a big deduction now may be worth less than relief in future, higher-profit years.
- Rising income: if you expect to move into a higher tax bracket, saving some relief for later may help.
- Lender or investor views: very low taxable profit can sometimes affect how lenders view your accounts, though accounting profit and taxable profit are separate.
- Selling soon: if you might sell the asset quickly, the tax treatment of the sale can claw back some of the benefit.
Financing does not usually stop you from claiming these reliefs, but the type of agreement matters. Hire purchase, leases and loans can be treated differently, so check before you sign.
Common mistake
Forgetting about the asset after the write-off. If you fully deduct an item and later sell it, the sale proceeds can become taxable or reduce your pool. Keep the asset register up to date so nothing surprises you later.
Your equipment write-off checklist
- List the equipment you plan to buy this year and why
- Check the current Section 179 limits or UK allowance rules
- Ask your accountant which relief fits each purchase
- Save invoices and payment proof in one folder
- Record purchase and in-service dates
- Track business use for mixed-use items
- Keep an asset register and update it when you sell or scrap items
Frequently asked questions
Can I use Section 179 for used equipment?
Used equipment can qualify as long as it is new to your business and meets the other conditions. Check the current IRS rules or ask your tax preparer for your specific case.
Can sole traders in the UK claim the Annual Investment Allowance?
Yes. The AIA is available to sole traders, partnerships and limited companies. Full expensing, by contrast, is for companies. If you use simplified cash basis accounting, the treatment of equipment can differ, so check GOV.UK.
Do cars count for these write-offs?
Cars usually follow special rules in both countries. In the UK, cars are generally excluded from the AIA, and in the US, there are specific limits for passenger vehicles. Vans and trucks are often treated differently from cars, so ask before you buy.
Related reading
The bottom line
Writing off equipment is one of the more generous parts of the tax system for small businesses. In the US, Section 179 can let you deduct qualifying equipment in full in the year it is placed in service. In the UK, the Annual Investment Allowance and full expensing do much the same through capital allowances.
Buy what the business genuinely needs, keep clean records of every purchase, and check the current rules with a qualified accountant each year. Do that, and the tax relief becomes a welcome bonus instead of a guessing game.
