Carpenter & Joiner Tax UK 2026/27: CIS, Tools and a £36,000 Example
Self-employed carpenters working for contractors are usually paid under the Construction Industry Scheme, with tax deducted before they're even paid. Full worked example on £36,000 turnover and reclaiming CIS deductions.
Why CIS changes the shape of a carpenter's tax year
Most self-employed traders receive their income gross and settle their whole tax bill through Self Assessment after the year ends. Carpenters and joiners working as subcontractors for building contractors are different: under the Construction Industry Scheme, the contractor deducts 20% (registered subcontractors) or 30% (unregistered) from each payment and sends it straight to HMRC, before the carpenter sees a penny. This means most of the tax year is spent effectively pre-paying tax at source, with the final Self Assessment return reconciling what's actually owed against what's already been deducted.
Self-Employed Tax Calculator
Calculate income tax, Class 2 and Class 4 National Insurance for self-employed and sole traders for 2025/26.
Open Self-Employed Tax calculatorWorked example: £36,000 gross CIS turnover
Gross turnover (invoiced to contractors): £36,000
CIS deducted at source (20%, registered subcontractor): £7,200
Deductible expenses:
- Tools and power tools: £1,800
- Materials not recharged to contractor: £1,500
- Van running costs/mileage: £2,200
- Public liability insurance: £350
- PPE and workwear: £250
- Accountancy fees: £400
- Total expenses: £6,500
Taxable profit: £36,000 − £6,500 = £29,500
Income tax: (£29,500 − £12,570) × 20% = £16,930 × 20% = £3,386
Class 4 NI: (£29,500 − £12,570) × 6% = £16,930 × 6% = £1,016
Total actual tax and NI owed: £4,402
CIS already deducted: £7,200 — Refund due: £7,200 − £4,402 = £2,798
Take-Home Pay Calculator
Calculate your net salary after income tax, National Insurance and student loan deductions.
Open Take-Home Pay calculatorWhy CIS almost always overshoots for tradespeople with real costs
CIS is deducted on your labour element of invoices (roughly), calculated before any of your actual business expenses are taken into account. Since carpentry involves genuine costs — tools, van running costs, materials, insurance — the 20% deducted at source is very often more than the real tax and NI eventually owed once those expenses reduce taxable profit. That's why a CIS refund at the end of the tax year is the norm, not the exception, for most working subcontractor carpenters.
Deductible expenses checklist
- Hand tools and power tools (Annual Investment Allowance for bigger items)
- Materials and consumables not separately recharged
- Van running costs or mileage
- Public liability insurance
- PPE and protective workwear
- Accountancy fees
Filing and paying
Register as a CIS subcontractor to secure the 20% (rather than 30%) deduction rate, keep every CIS payment/deduction statement from contractors, and file your Self Assessment return by 31 January following the tax year end to reconcile CIS deductions against your actual liability and claim any refund.
uk-self-employed-allowable-expensesFrequently asked questions
What is the Construction Industry Scheme and how does it affect carpenters?
The Construction Industry Scheme (CIS) requires contractors to deduct money from a subcontractor's payments and pass it to HMRC as an advance payment toward the subcontractor's tax and National Insurance. Registered subcontractors have 20% deducted; unregistered ones have 30% deducted. This is deducted before you're even paid, which is different from most self-employed trades where you receive gross income and pay tax later via Self Assessment.
How do I get my CIS deductions back if too much tax was taken?
You claim CIS deductions as a credit against your Self Assessment tax bill at the end of the year — if the 20% (or 30%) deducted across the year exceeds your actual income tax and Class 4 NI liability once expenses are accounted for, HMRC refunds the difference. This is extremely common for carpenters with significant tool and material costs, since CIS is deducted on the labour/gross amount, not your net profit.
Can carpenters claim tools and equipment as an expense?
Yes. Hand tools, power tools and larger equipment are deductible, either as a straightforward revenue expense for smaller items or via the Annual Investment Allowance for bigger purchases, letting most self-employed carpenters deduct the full cost in the year of purchase.
How much tax does a carpenter get back on £36,000 turnover after 20% CIS deductions?
If £36,000 gross turnover had 20% CIS deducted at source (£7,200), and actual expenses of around £6,500 bring taxable profit down to £29,500, the real income tax and Class 4 NI liability is roughly £4,394 — meaning a refund of around £2,806 once the CIS deductions are reconciled against the actual bill.
Do carpenters need to verify their CIS status with contractors?
Yes — contractors are required to verify a subcontractor's CIS registration status with HMRC before making payments, which determines whether 20% or 30% is deducted. Registering for CIS as a subcontractor (rather than remaining unverified) is what secures the lower 20% deduction rate.
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