Do plumbers have to join WaterSafe?

Joining is not compulsory to work as a plumber, but it is what makes you an approved contractor. Approved contractors can install specified water fittings without first notifying the water undertaker and getting its consent, which everyone else has to do before the work starts.

How much public liability insurance does a plumber need?

There is no legal minimum, but a WaterSafe approved business has to hold £2m of public liability insurance and, where it employs people, £5m of employers' liability cover. Most landlords and letting agents ask for proof of public liability before you start work.

Do I need Gas Safe registration to work on boilers?

Yes. Any gas work in the course of business has to be done by a member of the class of persons approved by the Health and Safety Executive, which is the Gas Safe Register. It covers domestic, commercial and industrial gas installations.

Should I start as a sole trader or a limited company?

A sole trader registers for Self Assessment with HMRC once they earn more than £1,000 in a tax year, and is personally responsible for all the debts of the business. A limited company is registered at Companies House and is legally separate from its owners, so they are responsible for business debts only up to what they invested.

Plumber Business Startup Checklist

Sol WrightCo-founder, Tradehand

Published 6 May 2026Updated 19 August 2026

Everything you need to launch a compliant, professional plumbing business in the UK, from WaterSafe and Gas Safe registration through to tools, van stock, and your first customers.

What's included

Legal structure registration (Ltd vs sole trader)
WaterSafe approved contractor scheme membership
Gas Safe registration for gas work (if applicable)
Insurance requirements and minimum cover amounts
Essential tools checklist for a plumbing start-up
Van stock list for common emergency callouts
Accounting software setup guidance
How to win your first customers with your Tradehand assistant

Preview: first 5 steps

Decide between sole trader (simpler, HMRC Self Assessment) or limited company (more protection, more admin). Most plumbers start sole trader and convert later.

Join WaterSafe (approved contractor scheme)

WaterSafe is the national accreditation body for approved plumbers across England, Scotland, Wales and Northern Ireland. Approved contractors can install certain water fittings without giving the water supplier prior notice under the Water Supply (Water Fittings) Regulations 1999.

Public liability insurance (minimum £2m)

PLI covers you if you cause damage to a customer's property or injure a third party. Most landlords and letting agents require proof before you start work, and £2m is what WaterSafe requires of an approved business, alongside £5m employers' liability cover where appropriate.

Gas Safe registration if doing gas work

It is illegal to carry out gas work without being a member of the class of persons approved by the HSE , the Gas Safe Register. The scheme covers domestic, commercial, and industrial gas installations.

Essential tools: pipe cutters, press fit tools, leak detection

Minimum toolkit: pipe cutters (15mm and 22mm), pipe bender, press fit crimping tool, leak detection kit, and a set of isolation valves. Add expansion tools for MLCP.

Plumber Business Startup Checklist

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