Unlike electricians and gas engineers, there is no legal requirement for plumbers in the UK to hold a specific licence. Anyone can call themselves a plumber. This means the due diligence falls entirely on you — and knowing what to look for can protect you from poor workmanship, overcharging, and legal liability.
Start with Gas Safe registration (if gas work is involved)
If any part of the job involves gas — boiler installation, gas pipework, cooker connections — the engineer must be Gas Safe registered by law. This is non-negotiable. Gas Safe Register is the official UK register, and you can verify any engineer at gassaferegister.co.uk by entering their registration number or business name.
Never allow unlicensed gas work. It is illegal, invalidates your home insurance, and can be fatal. Always check the engineer's ID card before work begins — it lists exactly which gas appliances they are qualified to work on.
Check WaterSafe for plumbing work
WaterSafe is a government-approved scheme for plumbers in England and Wales. Members must demonstrate competency and adhere to Water Regulations. Plumbers who are WaterSafe approved can self-certify plumbing work without the need for a separate local authority inspection.
WaterSafe membership is voluntary but is a strong indicator of professionalism. Search the register at watersafe.org.uk.
Look for CIPHE or APHC membership
- CIPHE (Chartered Institute of Plumbing and Heating Engineering): The professional body for the industry. Chartered Members have demonstrated high levels of competence and experience.
- APHC (Association of Plumbing and Heating Contractors): A trade association for businesses. Member companies have agreed to a code of professional conduct and offer consumer protection schemes.
Verify through Companies House
If a plumber operates as a limited company, their accounts are filed at Companies House. A trading history of several years with filed accounts is a positive signal. Very new companies with no filing history warrant more caution.
Ask the right questions before hiring
- Are you Gas Safe registered? (If gas work is involved — ask to see the card)
- Do you have public liability insurance? (Ask for the certificate)
- Do you offer a written guarantee on your work, and for how long?
- Will you provide a written quote before starting work?
- Can you provide references from recent similar jobs?
Red flags to watch for
- Unwilling to provide a written quote or contract
- Asks for a large cash deposit upfront (over 25% is unusual)
- No fixed business address or verifiable contact details
- Pressure to start work immediately without a written agreement
- No insurance documentation when asked
Use TopTenTrades to find verified ethical plumbers
Every plumber listed on TopTenTrades has been verified against public registers. Our Social Ethics Score covers not just accreditations but also employment practices, tax responsibility, and community investment — so you can hire with confidence that your money is going to a business that genuinely gives back.