What Expenses Can Subcontractors Claim?

If you are working long days on site, chasing payments and trying to keep CIS deductions straight, tax admin usually drops to the bottom of the pile. That is exactly why so many people ask what expenses can subcontractors claim - because getting it right can lower your tax bill, improve your records and stop you missing legitimate costs that come with doing the job.

For UK subcontractors, the basic rule is straightforward. You can usually claim expenses that are wholly and exclusively for your work. In plain terms, that means the cost must be genuinely for the business, not mainly for personal use. The detail matters, though, because some expenses are fully allowable, some are partly allowable, and some are not claimable at all.

What expenses can subcontractors claim under HMRC rules?

HMRC does not work on guesswork or rough estimates. If you are claiming costs on a self assessment tax return, you need to be able to show what you spent, why you spent it and how it relates to your subcontracting work. Good bookkeeping is not just about staying tidy - it is what supports the claim if HMRC ever asks questions.

In practice, most allowable expenses for subcontractors fall into a few regular categories: travel, tools and equipment, protective clothing, phone and office costs, insurance, training in some cases, and professional fees. The challenge is usually not finding expenses. It is separating genuine business costs from day-to-day personal spending.

Travel to temporary sites

Travel is one of the most common areas subcontractors ask about. If you are travelling to a temporary workplace, that cost is often allowable. This can include mileage if you use your own vehicle, or actual costs such as fuel, parking, train fares or tolls, depending on how you work out your claim.

The grey area is ordinary commuting. If you are travelling to the same permanent site every day over a long period, HMRC may treat that as normal commuting, which is not usually allowable. This is where facts matter. Two subcontractors in similar trades can end up with different treatment depending on the contract, the site duration and whether the workplace is temporary.

If you use your own van or car for both work and private journeys, you can only claim the business-use element. That means keeping a proper mileage log or another reliable record. Estimating after the year-end is where people get caught out.

Tools, equipment and materials

If you buy tools you need for the job, these are often claimable. The same goes for equipment and materials you pay for yourself rather than being reimbursed by the contractor. For many trades, this is a major area of cost and one worth tracking carefully.

Smaller items may be claimed as day-to-day business expenses, while larger purchases can fall under capital allowances. The tax treatment is not always identical, but either way the cost may still be deductible. What matters is how the item is used and whether it is for the business.

If there is mixed use, the personal element should be stripped out. For example, if you buy a laptop that is partly for quoting jobs and accounts but also used by the family at home, only the business proportion should be claimed.

Protective clothing and uniforms

There is a clear difference between protective workwear and everyday clothing. Items such as safety boots, hard hats, high-vis jackets, gloves and goggles are normally allowable because they are specifically required for the work.

Standard clothing, even if you wear it only on site, is a different story. Jeans, T-shirts and ordinary jackets are usually not claimable just because they are practical for work. HMRC tends to take a firm view here, so it is worth getting the distinction right.

Phone, internet and working from home

Subcontractors often run a lot of admin from home, even if the actual job happens on site. Calling suppliers, invoicing contractors, completing tax paperwork and storing records all count as part of running the business.

If you use your mobile phone for work, you can claim the business-use part of the bill. The same principle applies to internet costs if you use broadband for business admin. If there is clear mixed use, the claim needs to be apportioned fairly.

Working from home can also create allowable costs. You may be able to claim a proportion of household expenses or use HMRC's simplified flat rate method, depending on your situation. This usually covers the business use of home for admin rather than the physical trade itself. It is rarely a huge claim, but it is often worth including if you regularly handle paperwork from home.

Insurance and financial costs

Public liability insurance, professional indemnity insurance where relevant, tools insurance and other business insurance policies are generally allowable. These are normal costs of protecting yourself and your work.

Bank charges on a business bank account can also be claimed, along with interest on business loans in some cases. If you use a personal bank account for business, you need to separate out only the charges that relate to the business side. This is one reason many subcontractors find it easier to keep business finances separate from the start.

Accountancy fees and office costs

Fees for your accountant, bookkeeping software, stationery, postage and similar admin costs are normally allowable. If you pay for help with your self assessment tax return or CIS records, that is generally a business expense where it relates to your trading income.

This is often an easy area to miss because the costs can feel small compared with vehicle or tools spending. Over a full tax year, though, they add up. More importantly, these are the costs of staying compliant, which matters just as much as reducing tax.

Training, subscriptions and professional costs

Some training costs can be claimed, but this depends on the purpose of the course. If the training updates existing skills or maintains knowledge you already use in your subcontracting work, it may be allowable. If it gives you a completely new skill or moves you into a new trade area, HMRC may treat it as capital in nature and disallow it.

Trade association fees or professional subscriptions can also be allowable where they are relevant to your work. Again, the link to your current business needs to be clear.

This is one of those areas where a quick assumption can cause problems. The fact that a course helps your career does not automatically make it deductible for tax.

What subcontractors usually cannot claim

Knowing what not to claim is just as important. Everyday meals are usually not allowable unless there is a genuine business travel reason that makes the cost part of a work journey. Ordinary lunches on site are normally treated as personal living costs.

Personal clothing, gym memberships, most fines and penalties, and private medical costs are also usually non-allowable. The same applies to the private element of any mixed-use purchase. If an expense has a strong personal benefit and only a weak business link, HMRC is unlikely to accept the claim.

That does not mean every borderline expense is automatically wrong. It means you need to be realistic. A sensible, evidence-backed claim is far better than pushing for everything and inviting questions later.

Records matter as much as the expense itself

A perfectly valid expense can still become a problem if you cannot support it. Keep receipts, invoices, bank records and mileage logs. Digital copies are fine as long as they are readable and organised.

This is especially important for subcontractors because income under CIS is already being reported and deductions may already have been taken at source. When your tax return is prepared, the expenses side needs to be just as accurate as the income side. That is often where the final tax position - including whether you are due a refund - is really determined.

At Short And Sons Accountants Ltd, this is where practical support makes a difference. It is not just about filing figures with HMRC. It is about helping subcontractors claim what they are entitled to without wandering into risky territory.

When it is worth getting advice

If your costs are simple and well recorded, your claim may be fairly straightforward. But if you use your vehicle for mixed purposes, work across changing sites, buy expensive equipment, or are unsure whether a course or home cost qualifies, advice can save both money and hassle.

The right answer is not always the most aggressive one. Sometimes the better route is the claim that is clearly supportable, easy to evidence and less likely to be challenged. That approach tends to serve subcontractors better over the long run than stretching the rules for a slightly bigger deduction.

The main thing is this: if a cost is genuinely for your subcontracting work, there is a good chance it may be claimable, but the detail decides everything. Keep solid records, separate business from personal spending where you can, and treat your expenses with the same care you give the work itself. That usually leads to a cleaner return, fewer surprises and a fairer tax result.