Guide

How to check a plumber

Short answer

Search the WaterSafe register, which lists plumbers from several approved contractor schemes. An approved contractor gives you a signed certificate that says if the work meets the water fittings rules. Check a limited company on Companies House. For any gas work, the engineer must be on the Gas Safe Register by law.

Updated 15 October 2026 · 2 min read · 11 sources

Check the WaterSafe register

WaterSafe is the national register of plumbers in approved contractor schemes. It brings together the approved contractor schemes, including APHC, CIPHE and the Water Industry Approved Plumbers’ Scheme.

An individual, not the business, becomes an approved contractor, for a set scope of work. Check that the person who does your job is an approved contractor for that kind of work.

Search WaterSafe by your postcode or by the firm’s name.

What an approved contractor can certify

Under regulation 6 of the Water Supply (Water Fittings) Regulations 1999, an approved contractor gives you a signed certificate when the work is done. It says if the fittings comply with the regulations.

Some jobs need notice to the water company before work starts. An approved contractor can do some of them without the notice, such as a bidet with an upward spray.

WaterSafe says the certificate gives you a legal defence, if the approved contractor holds that scope of work. Keep it with your house papers.

Check the other registers

Other registers cover other parts of the job. Use the one that fits the work.

APHC: firms that are members of the Association of Plumbing and Heating Contractors.
CIPHE: members of the Chartered Institute of Plumbing and Heating Engineering.
Gas Safe Register: by law, anyone who works on gas in your home must be on it. This includes gas boilers.
TrustMark: the Government Endorsed Quality Scheme for work in and around the home.
Companies House: check that a limited company is active, and see its registered address.

Questions to ask before you book

Ask each firm the same questions, so you can compare them fairly.

Are you on the WaterSafe register, and for which type of work?
Will I get a water regulations certificate when the job is done?
Will you tell the water company or building control, if the job needs it?
Do you have public liability insurance? Can I see the certificate?
Is the quote fixed, or an estimate? Does it include VAT?

How our listings help

We are a directory. We do not do the work, and nobody pays for position. For each firm we show the register checks we did, the date, and a link to the register.

We do not check the quality of work or insurance unless a firm sends proof. If we did not find a firm on a register, we show nothing for that register, because a search can miss a firm.

Questions

Does a plumber have to be registered?

Not for most water work. But only an approved contractor can give you the certificate under the water fittings rules. For gas work, the engineer must be on the Gas Safe Register by law.

Is WaterSafe a government register?

WaterSafe describes itself as a free online directory and national accreditation body for competent and qualified plumbers. It lists approved contractors from several schemes.

What if I cannot find the plumber on WaterSafe?

Ask which scheme they belong to and search that scheme. Only an approved contractor can give you the certificate.