As a CIS subcontractor, every legitimate business expense you claim reduces your taxable profit — which means a bigger tax refund. If you haven't started the refund process yet, read our guide on how to claim your CIS tax refund first. HMRC allows you to deduct any cost that is "wholly and exclusively" for your construction work. Here is the complete list of CIS expenses you can claim in 2025/26.
The Rule: "Wholly and Exclusively"
HMRC's golden rule is simple: if you spent the money purely for your work, you can claim it. If it's partly personal, you can usually claim the business portion. If it's entirely personal, you can't claim it at all.
You must keep evidence — receipts, invoices, bank statements, or a mileage log — for at least 6 years.
Travel and Vehicle Costs
Travel is typically the biggest expense category for construction subcontractors. You can claim travel to temporary workplaces — that means any site where you work for less than 24 months.
Option 1: Simplified mileage rate Use HMRC's flat rate if you use your own car or van:
- 45p per mile for the first 10,000 miles
- 25p per mile after that
- Motorcycles: 24p per mile
- Bicycles: 20p per mile
Option 2: Actual vehicle costs Claim the business proportion of your actual running costs: fuel, insurance, road tax, MOT, repairs, servicing, breakdown cover, and parking. You'll need to keep a log of business vs. personal miles.
You can also claim:
- Tolls, congestion charges, and parking fees on work journeys
- Public transport fares to temporary sites
- Hotel or B&B costs when working away from home overnight
You cannot claim:
- Travel to your regular place of work (a site you attend for 24+ months)
- Travel between home and a permanent workplace
- Commuting costs
Tools and Equipment
If you buy tools for your work, you can claim them. This includes:
- Hand tools (spanners, screwdrivers, hammers, tape measures, spirit levels)
- Power tools (drills, saws, grinders, nail guns)
- Ladders and scaffolding equipment
- Specialist trade tools (pipe benders, cable pullers, plastering hawks)
- Tool bags, belts, and boxes
- Replacement batteries and blades
- Tool insurance
Capital allowances: For expensive equipment (over £1,000), you may need to claim via Annual Investment Allowance rather than deducting the full cost in one year. Most CIS subcontractors fall well within the £1 million AIA limit and can deduct the full cost immediately.
Protective Clothing and Safety Equipment
Construction-specific clothing that you wouldn't wear outside of work is fully claimable:
- Steel-toe cap boots and safety shoes
- Hard hats and bump caps
- Hi-visibility vests and jackets
- Safety glasses and goggles
- Ear defenders and ear plugs
- Dust masks and respirators
- Gloves (work gloves, rigger gloves, cut-resistant gloves)
- Waterproof clothing (jackets, trousers, overalls)
- Knee pads
- Harnesses and fall protection equipment
- Sun protection (on-site sunscreen for outdoor work)
You cannot claim: Ordinary clothes, even if you only wear them for work. Jeans, trainers, and hoodies don't count unless they're branded uniform or protective.
Insurance
- Public liability insurance
- Professional indemnity insurance
- Tool and equipment insurance
- Employer's liability insurance (if you hire workers)
You cannot claim personal life insurance or health insurance premiums.
Phone and Internet
If you use your phone for work, you can claim the business proportion. If you have a phone solely for work, claim 100% of the costs. For a phone shared between work and personal use, estimate the business percentage (commonly 50-75%).
This includes monthly contracts, pay-as-you-go costs, and the cost of the handset itself if bought for work.
Accountancy and Professional Fees
- Accountant fees for preparing your tax return
- Tax advice costs
- Bookkeeping software subscriptions
- Construction Skills Certification Scheme (CSCS) card renewal
- Professional body memberships and union fees
- DBS check fees (if required for work)
Training and Qualifications
You can claim for training that maintains or improves skills in your current trade:
- CSCS card training and testing
- CITB courses
- Health and safety courses (SMSTS, SSSTS)
- First aid training
- Asbestos awareness
- Working at height training
- Trade-specific CPD courses
You cannot claim: Training for a completely new trade or career. If you're a plumber training to become an electrician, that's not claimable.
Subsistence (Food and Drink)
When working away from your normal area, you can claim reasonable meal costs:
- Breakfast, lunch, and evening meals when at a temporary workplace
- Drinks (non-alcoholic, work-related)
HMRC expects "reasonable" costs. A sandwich and a drink is fine. A three-course restaurant meal every night will raise questions.
You cannot claim: Meals at or near your regular workplace, or food you'd eat anyway.
Materials and Consumables
If you supply your own materials on a job, you can claim the cost:
- Building materials you've purchased
- Consumables (sandpaper, sealant, screws, nails, tape, drill bits)
- Waste disposal costs
- Cleaning products for equipment
Office and Administrative Costs
- Stationery and printing
- Postage
- Computer or tablet (if used for work admin, invoicing, tax)
- Software subscriptions (accounting, invoicing, project management) — with Making Tax Digital arriving in April 2026, these may become essential
- Business bank account fees
Working from Home
If you do admin work from home (invoicing, quoting, record-keeping), you can claim a proportion of household costs:
Simplified method: Claim a flat rate based on hours worked from home per month:
- 25-50 hours: £10/month
- 51-100 hours: £18/month
- 101+ hours: £26/month
Actual cost method: Calculate the business proportion of mortgage interest/rent, utilities, council tax, and broadband.
Hire and Subcontractor Costs
- Hired plant and equipment (cherry pickers, excavators, generators)
- Skip hire and waste removal
- Payments to other subcontractors you hire to help on a job
Expenses by Trade — Quick Reference
| Trade | Top Claimable Expenses |
|---|---|
| Plumber | Pipe cutters, soldering equipment, van costs, plumbing materials |
| Electrician | Multimeters, cable tools, conduit benders, testing equipment |
| Bricklayer | Trowels, levels, line and pins, mixer hire, mortar materials |
| Carpenter | Saws, chisels, planes, workbenches, timber (if self-supplied) |
| Plasterer | Hawks, trowels, mixing drills, stilts, plaster (if self-supplied) |
| Painter/Decorator | Brushes, rollers, dust sheets, paint (if self-supplied), ladders |
| Roofer | Harnesses, roofing tools, ladders, felt/flashing materials |
| General Labourer | PPE, travel, tools, subsistence (often the biggest refund category) |
Common Mistakes to Avoid
- Claiming personal expenses — HMRC can check your return and impose penalties for false claims
- Not keeping receipts — No evidence means no claim if HMRC investigates
- Missing travel expenses — This is the most commonly forgotten category and often the largest
- Not claiming for previous years — You can go back 4 years
- Inflating expenses — Some dodgy refund companies do this. It's illegal and you're responsible, not them
How Expenses Affect Your Refund
A simple example:
- CIS income (gross): £40,000
- CIS deducted (20%): £8,000
- Allowable expenses: £6,000
- Taxable profit: £34,000
- Personal allowance: £12,570
- Income tax (20% on £21,430): £4,286
- Class 4 NIC (6% on £21,430): £1,285.80
- Total actually owed: £5,571.80
- CIS already paid: £8,000
- Your refund: £2,428.20
Every extra pound of legitimate expenses you claim reduces your taxable profit and increases your refund. See our worked examples for how much CIS refund you could get by trade.
Want to see your exact numbers? Try our free CIS tax refund calculator.
Frequently Asked Questions
Can I claim for tools bought in previous years?
Yes, if you haven't already claimed them. You can amend tax returns or file for up to 4 previous years.
What if I don't have receipts?
Bank and card statements can serve as evidence for most expenses. But HMRC prefers itemised receipts where possible. Start keeping them now.
Can I claim for my CSCS card?
Yes. The cost of obtaining, renewing, or upgrading your CSCS card is a legitimate business expense.
How do I split expenses between personal and business?
Use a reasonable estimate. For a phone used 70% for work, claim 70% of the cost. Be consistent and keep a record of how you calculated the split.
Can I claim for parking at site?
Yes. Parking fees at temporary work sites are a legitimate travel expense. However, parking near a site you attend for 24+ months (your permanent workplace) is not claimable.
Do I need separate receipts for each tool?
Ideally yes — individual receipts make claims easier to evidence. But if you buy multiple tools in one transaction, a single itemised receipt covering all items is fine. Keep the receipt for at least 6 years.
Are National Insurance contributions an expense?
No. Class 4 NICs are calculated as part of your Self Assessment and are separate from your business expenses. Class 2 NIC is no longer mandatory from April 2024.
Related Guides
- How to Claim Your CIS Tax Refund — Step-by-step guide to claiming your refund from HMRC
- How Much CIS Refund Will I Get? — Worked examples showing how expenses affect your refund amount
- Making Tax Digital for CIS Subcontractors — What changes from April 2026 and how to prepare
Last updated: September 2025. Uses 2024/25 and 2025/26 HMRC rates. This is general guidance — for advice on your specific situation, consult a qualified tax professional.