Plumber

Fix your tax affairs with this guide for self-employed plumbers.

Allowable Expenses

• Materials & Parts — Pipes, fittings, valves, boiler parts, and materials purchased for jobs. Keep all supplier invoices.
• Van & Vehicle Costs — Van insurance, servicing, fuel (use mileage rate or actual costs), and commercial vehicle tax.
• Tools & Equipment — Pipe cutters, soldering equipment, pressure testing kits, and power tools — claim via Annual Investment Allowance.
• Gas Safe Registration — Annual Gas Safe Register fee — required for gas work and fully deductible as a professional licence.
• PPE & Workwear — Safety boots, overalls, gloves, and hi-vis clothing worn exclusively for work.
• Insurance — Public liability and tools insurance — essential for sole trader tradespeople.

Tax Tips

• Gas Safe registration is legally required for gas work — it is also a fully deductible business cost.
• Materials purchased for specific jobs are a cost of goods sold — keep job records to match materials to invoiced work.
• The Construction Industry Scheme (CIS) applies if you work as a subcontractor for a contractor — you may have 20% tax deducted at source, which you reclaim on Self Assessment.
• Van running costs are substantial — use the actual cost method for vans (not the mileage rate, which applies to cars) to claim the full business proportion.

Frequently Asked Questions

What is the Construction Industry Scheme (CIS) and does it affect me?

CIS is a scheme where contractors deduct tax at source from payments to subcontractors in the construction industry. If you are a plumber working as a subcontractor, 20% is deducted and paid to HMRC on your behalf. You reclaim any overpaid tax on your Self Assessment return.

Do I need Gas Safe registration to claim those costs?

You need Gas Safe registration to legally carry out gas work regardless of tax. The annual registration fee is a professional licence cost and fully deductible. Without valid Gas Safe registration, you cannot legally install, repair, or service gas appliances.

Can I claim a van as a business expense?

Yes. A van used for business is not subject to the mileage rate rules that apply to cars. You can claim actual running costs (fuel, insurance, servicing, MOT) for a van. If used privately as well, claim only the business proportion.

Can I claim tools stolen from my van?

If your tools are stolen and you are not fully reimbursed by insurance, the unrecovered loss may be claimable as a deductible business expense. If the original tool costs were claimed through AIA, the insurance payout reduces the loss. Keep a tools inventory and crime reference number as evidence.