CIS Subcontractor Expenses: The Complete List of What You Can Claim

Most CIS subcontractors claim far fewer expenses than they're entitled to — and leave hundreds or thousands of pounds with HMRC as a result. Every pound of allowable expense reduces your taxable profit and increases your refund. This guide covers every expense you can claim in 2026/27: tools, mileage at 55p per mile, PPE, insurance, training, phone, and more.

Back to all articles

CIS Tax · 10 min read ·

CIS Subcontractor Expenses: The Complete List of What You Can Claim
CIS Subcontractor Expenses: The Complete List of What You Can Claim in 2026/27

QuoteDone · CIS Tax Guides

CIS Subcontractor Expenses: The Complete List of What You Can Claim in 2026/27

Published by QuoteDone Editorial Team  ·  Aligned to HMRC 2026/27 Tax Year

Most CIS subcontractors claim far fewer expenses than they're entitled to. Every pound of allowable expense reduces your taxable profit — which means less tax owed and a bigger refund from HMRC. Here's every expense you can claim, with examples.

55p Per mile for first 10,000 business miles
5 years How long to keep expense records
£1 in = £1 off Every allowable expense reduces your tax bill

When HMRC calculates your CIS refund, they don't just look at how much was deducted from your payments. They look at your taxable profit — your income minus your allowable business expenses. The lower your taxable profit, the less tax you owe, and the bigger the refund.

This is where most subcontractors lose money — not by failing to register, not by filing late, but by not claiming everything they're entitled to. Tools they bought, miles they drove, insurance they paid, training they completed — all of it reduces the tax bill. All of it goes unclaimed by thousands of subcontractors every year.

"The most common reason subcontractors miss out on their full refund is underclaiming expenses. Many don't claim mileage at all, forget accountancy costs, or fail to separate materials from labour."

— QuoteDone CIS Tax Guides
💡 Did You Know? The most common reason CIS subcontractors miss out on their full refund isn't a missing deduction statement or a late return. It's simply not claiming the expenses they're legally entitled to. Mileage alone — at 55p per mile — can add thousands to your refund. Are you one of the thousands who's been driving to sites all year without claiming a penny?

The Golden Rule: Wholly and Exclusively

HMRC's rule for allowable expenses is simple: wholly and exclusively for the purpose of your business. If you bought something for work and only work, you can claim the full cost. If you bought something with a personal element, you can claim the business proportion only.

A dedicated work phone — 100% claimable. A personal phone used partly for work — claim the business percentage only. A van used only for work — 100% claimable. A car used for work and personal journeys — claim the business proportion or use the mileage rate instead.

📊 Want to see what your refund looks like with expenses included? Use our free CIS Refund Calculator →

✓ No registration required  ·  100% Free  ·  HMRC 2026/27 Aligned

The Complete Expenses List

1. Tools and Equipment

🔧 Tools and Equipment — What You Can Claim

✓
Hand tools Hammers, screwdrivers, chisels, spanners, spirit levels, tape measures, wire strippers — anything you bought for the job.
✓
Power tools Drills, grinders, circular saws, nail guns, jigsaws, sanders. Full cost claimable in year of purchase for tools under £1,000 used mainly for business.
✓
Tool bags, belts, and storage Cases, bags, toolboxes, and storage units purchased for transporting or organising work tools.
✓
Tool hire Hired equipment — scaffold, access platforms, specialist machinery — for specific jobs.
✓
Tool repairs and maintenance Cost of repairing or servicing tools you use for work.
✓
Measuring and testing equipment Laser levels, multimeters, pipe pressure gauges, survey equipment.
⚠️ Keep Receipts for Everything HMRC can request receipts during an enquiry. A bank statement showing a payment to Screwfix or Toolstation is supporting evidence but not a substitute for a receipt or invoice. If you lost a receipt, reconstruct what you can and keep notes.

2. Vehicle and Travel Costs

This is the biggest expense most CIS subcontractors underclaim — partly because they don't keep mileage logs and partly because they don't know the current rate has increased.

🚗 Vehicle and Travel — What You Can Claim

✓
Mileage at 55p per mile (first 10,000 miles) The HMRC approved mileage rate for 2026/27. Covers fuel, wear and tear, and running costs. 25p per mile above 10,000 miles. If you claim mileage, you cannot also claim fuel or servicing.
✓
Actual vehicle running costs (alternative to mileage) Fuel, insurance, servicing, MOT, road tax, repairs — business proportion only. Choose one method (mileage or actual costs) and stick with it for that vehicle.
✓
Parking fees Site parking, town centre parking for work-related visits. Not parking fines.
✓
Public transport and tolls Train, bus, or tube fares for business journeys. Congestion charge, tolls, and ferry costs for work travel.
✗
Commuting from home to a permanent workplace HMRC does not allow you to claim travel between your home and a regular, fixed workplace. Travel to different sites is claimable — travel to the same site every day for a long period may not be.
🚗 Van or car? It affects what you can claim. Read Van or Car: The HMRC Test That Catches Thousands of CIS Workers before deciding how to claim your vehicle costs.

3. Materials and Consumables

🧱 Materials — What You Can Claim

✓
Materials you bought and were not reimbursed for Timber, cement, bricks, wiring, pipework, fixings — anything you purchased and supplied as part of a job without the contractor covering the cost.
✓
Consumables Blades, drill bits, sanding discs, cutting wheels, sealant, adhesive — items used up during work that need regular replacement.
✗
Materials reimbursed by your contractor If the contractor paid for or refunded materials, you cannot also claim them on your Self Assessment. Double-counting is an HMRC red flag.
⚠️ Materials on Your Invoice Materials listed separately on your invoice are excluded from CIS deduction by your contractor. But they still count as turnover on your Self Assessment — declare the full invoice amount as income, then claim materials as an expense. The net effect is the same, but the process matters.

4. PPE and Workwear

🦺 PPE and Workwear — What You Can Claim

✓
Personal Protective Equipment Safety boots, hard hats, high-vis vests, safety glasses, gloves, ear defenders, dust masks, knee pads, fall arrest harnesses.
✓
Specialist workwear Overalls, waterproofs, work trousers, steel-toecap boots. Must be clothing you wear specifically for work — not everyday clothing you happen to wear to site.
✗
Everyday clothing worn to site Jeans, t-shirts, and casual clothing are not allowable even if you only wear them for work. The item must be specialist or protective by nature.

5. Insurance

🛡️ Insurance — What You Can Claim

✓
Public liability insurance Essential for most CIS subcontractors. Fully claimable as a business expense.
✓
Professional indemnity insurance Relevant for design-and-build or technical roles. Fully claimable.
✓
Tools and equipment insurance Cover for your own tools and plant. Fully claimable.
✓
Van or vehicle insurance (business use) Business proportion of your vehicle insurance — or the full amount if the vehicle is used exclusively for work.

6. Phone and Communication

📱 Phone and Communication — What You Can Claim

✓
Business mobile phone If your phone is used exclusively for business, claim the full monthly bill and any handset cost.
✓
Personal mobile — business proportion If your phone is mixed use, claim the percentage used for business. HMRC typically accepts 50–80% for sole traders whose work requires regular calls and messaging.
✓
Broadband — business proportion If you use home broadband for work (invoicing, emails, admin), claim the business proportion.

7. Professional Fees

📋 Professional Fees — What You Can Claim

✓
Accountancy fees What you pay your accountant to prepare and file your Self Assessment. Fully claimable — and one of the easiest to forget.
✓
Legal fees (business related) Legal advice related to your business — contract disputes, debt recovery — is claimable. Personal legal matters are not.
✓
Tax agent or bookkeeper fees If you pay someone to keep your books or manage your records, that cost is claimable.

8. Training and Qualifications

🎓 Training and Qualifications — What You Can Claim

✓
CSCS card renewal The cost of renewing your Construction Skills Certification Scheme card is an allowable expense.
✓
Trade-specific courses Courses that update or extend your existing skills — asbestos awareness, working at height, first aid, IPAF, PASMA.
✓
Industry licences and registrations Gas Safe registration, NICEIC registration, CHAS, Constructionline — annual fees for accreditation required to work.
✗
Courses to enter a new trade Training to qualify in a completely new area is generally not allowable — it must update existing skills, not create new ones.

9. Use of Home as Office

🏠 Use of Home as Office — What You Can Claim

✓
HMRC flat rate — simplified method If you work from home 25+ hours per month, HMRC allows £10–£26/month without any calculation. The simplest method if you do invoicing and admin from home.
✓
Actual cost method Calculate the business proportion of heating, electricity, broadband, and mortgage interest (renters can include rent). Divide by number of rooms used for work and time spent. More complex but can give a higher claim.

10. Other Allowable Expenses

📦 Other Expenses — What You Can Claim

✓
Bank charges on your business account Monthly fees, transaction charges, or overdraft interest on a business bank account.
✓
Stationery and office supplies Printer ink, paper, invoicing software subscriptions, folders, stamps.
✓
Advertising and marketing Business cards, website costs, online adverts to find work.
✓
Subscriptions relevant to your trade Trade magazines, industry body memberships, reference materials directly related to your construction work.

How Expenses Affect Your Refund — A Realistic Example

Here's how expenses work in practice for a typical CIS subcontractor:

The Difference Expenses Make — £40,000 Gross CIS Income

Gross CIS income (turnover) £40,000
CIS deducted at 20% £8,000
Tools + PPE claimed £1,800
Mileage (8,000 miles × 55p) £4,400
Insurance + phone + training £800
Total expenses claimed £7,000
Taxable profit (£40,000 - £7,000) £33,000
Income after personal allowance £20,430
Income tax + Class 4 NIC £5,490
CIS already paid £8,000
Refund with £7,000 expenses claimed £2,510
✅ What Underclaiming Costs You If the subcontractor in this example claimed only £2,000 in expenses instead of £7,000, their taxable profit would be £38,000 instead of £33,000. The extra £5,000 of profit would cost approximately £1,000 in additional tax — money that went to HMRC unnecessarily. Every pound of legitimate expenses matters.

What You Cannot Claim

  • Commuting — travel between home and a fixed, regular workplace
  • Everyday clothing — clothing that isn't specialist or protective by nature
  • Personal expenses — food, drinks, personal hygiene, entertainment (unless entertaining clients — and even then, strict rules apply)
  • Fines and penalties — parking fines, speeding fines, HMRC late payment penalties
  • Reimbursed costs — anything your contractor paid for or refunded
  • Capital items not on CIS work — a holiday caravan, personal investments, home improvements

Record Keeping — What HMRC Expects

You must keep records of all expenses for at least 5 years after the 31 January filing deadline for the relevant tax year. For 2025/26 returns, that means keeping records until at least February 2032.

  • Keep receipts for all purchases — physical or digital photograph
  • Keep a mileage log — date, destination, business purpose, miles driven
  • Keep bank statements showing business outgoings
  • Keep insurance certificates and renewal notices
  • Keep training certificates and course receipts
  • Store digital copies — cloud storage, email to yourself, secure folder
📄 Filing your expenses on Self Assessment? Read How to Fill In Your Self Assessment as a CIS Subcontractor — covers which boxes to use for each expense category on SA103S.
💰 Ready to see your refund estimate? How to Claim a CIS Tax Refund: Step-by-Step Guide — covers the full Self Assessment process and how your expenses feed into the final calculation.

Frequently Asked Questions

Can I claim expenses if I don't have receipts?

HMRC expects receipts, but bank statements and other evidence can support claims where receipts are lost. For small routine purchases (drill bits, fixings, consumables) a reasonable estimate is often accepted if you can show a consistent pattern. For larger items, make every effort to obtain a duplicate receipt from the supplier. Going forward, photograph every receipt the moment you get it.

Can I claim expenses for tools I bought before I started CIS work?

For tools you owned before starting self-employment, HMRC may allow you to claim the current market value (not the original purchase price) at the point you started using them for business. This is known as introducing an asset — your accountant can help you value and claim these correctly.

Can I claim the cost of setting up my business?

Pre-trading expenses — costs incurred before you officially started trading — can be claimed as if they were incurred on your first day of trading, provided they were wholly and exclusively for the business. This includes tools purchased in preparation, insurance taken out before starting, and training completed before the first job.

Do I need to separate materials from labour on my invoices to claim expenses?

Yes — and this is important for two reasons. First, your contractor can only exclude the materials cost from CIS deduction if it's clearly identified on the invoice. Second, your Self Assessment requires you to declare full turnover and then deduct expenses — so having clear records of what was materials and what was labour keeps your return accurate and defensible.

People Also Ask

What expenses can a CIS subcontractor claim on their tax return?

CIS subcontractors can claim tools and equipment, materials they supplied, mileage at 55p per mile (first 10,000 business miles in 2026/27), PPE and workwear, public liability insurance, the business proportion of phone bills, accountancy fees, CSCS card and training costs, and use of home as office. All expenses must be wholly and exclusively for the business.

Can CIS subcontractors claim mileage?

Yes. The HMRC approved mileage rate for 2026/27 is 55p per mile for the first 10,000 business miles, and 25p above that. Keep a mileage log showing date, destination, and purpose of each journey. You cannot claim commuting from home to a fixed regular workplace — only journeys between sites and for business purposes.

How do expenses increase my CIS refund?

Every pound of allowable expense reduces your taxable profit. Lower taxable profit means less tax owed. Less tax owed means the gap between what CIS deducted and what you actually owe is bigger — which means a larger refund. On a typical £40,000 income with £7,000 in expenses, the difference can be over £1,400 in additional refund compared to claiming nothing.

Can I claim tools as a CIS subcontractor?

Yes. Tools, power tools, hand tools, measuring equipment, and consumables you purchased for your CIS work are allowable expenses. Keep receipts. For tools costing under £1,000 used mainly for business, you can claim the full cost in the year of purchase.

QuoteDone Tools

Know Your Expenses. Know Your Refund.

Use our free CIS Refund Calculator to estimate what HMRC owes you — and make sure every invoice separates labour and materials correctly.

CIS Refund Calculator Ready to claim your CIS refund? Use our free calculator to find out what HMRC owes you. CHECK YOUR REFUND NOW →
Free Invoice Generator Need professional invoices fast? Create clean, compliant invoices in seconds with our free tool. TRY FREE INVOICE GENERATOR →

This article is for informational purposes only and does not constitute formal tax, financial, or legal advice. Allowable expense rules and mileage rates are subject to change. Always check the latest HMRC guidance or consult a qualified accountant. Aligned to 2026/27 HMRC guidance.