Builder Tax Calculator 2025/26
Calculate your take-home pay as a self-employed builder or construction worker. Factor in CIS deductions, tool costs, and van expenses to see your real tax position.
Common deductions for builders
These are typical expenses you may be able to claim against your taxable profit.
Tools and power tools
Drills, saws, nail guns, levels, mixers, and other construction tools. Claim under the Annual Investment Allowance.
Van and vehicle costs
Work van or truck fuel, insurance, road tax, MOT, servicing, and repairs — business proportion.
Building materials
Timber, cement, plasterboard, screws, and other materials you supply that are not recharged to the client.
Work clothing and PPE
Hard hats, hi-vis vests, steel-toe boots, safety glasses, and dust masks required on site.
CSCS card and training
CSCS card renewals, health and safety courses, and trade qualification training.
Skip hire and waste disposal
Site clearance, skip hire, and waste disposal costs incurred during jobs.
Public liability insurance
Insurance premiums required for working on construction sites and client properties.
Subcontractor payments
Payments to other tradespeople you hire to work on your jobs (subject to CIS if applicable).
Yearly
£25,120
take-home
Monthly
£2,093
take-home
Weekly
£483
take-home
Deductions
Effective rate
16.27%
The actual percentage of your total income going to income tax and NI combined.Marginal rate
28%
The tax rate on your next £1 of income. Above £100k this can be 60% due to Personal Allowance tapering.Income tax bands
Where your money goes
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Try AI Tax Advisor — £9.99How does CIS affect a self-employed builder's tax?
Under the Construction Industry Scheme (CIS), contractors deduct 20% from your payments and send it to HMRC. This is not extra tax — it is an advance payment. When you file your Self Assessment, CIS deductions are offset against your tax bill. If more was deducted than you owe, you get a refund. Self-employed builders pay income tax on net profit (after expenses) and Class 4 NI at 6% on profits between £12,571 and £50,270.
- CIS deductions (20%) are advance tax payments, not additional tax
- Offset CIS against your Self Assessment tax bill
- Tools, van costs, PPE, and materials are deductible
- CSCS card and training fees are claimable
- File by 31 January to claim any CIS refund
Last reviewed:
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