How to choose a plumber in the UK

The one legal requirement: Gas Safe

Gas work is the exception to the general rule that plumbing is unregulated. Anyone working on gas appliances, boilers or pipework in the UK must be on the Gas Safe Register, which replaced CORGI in 2009. Working on gas without registration is a criminal offence, not a technicality.

Every registered engineer carries an ID card showing a licence number, an expiry date and, importantly, the specific types of gas work they are qualified for. An engineer qualified for cookers is not automatically qualified for boilers. Ask to see the card and check the number on the Gas Safe Register website.

For non-gas work, look for accountability instead

General plumbing: leaks, bathrooms, drainage: carries no licensing requirement. That does not leave you without checks; it just means you are looking for accountability rather than a licence.

Membership of a trade body such as the Chartered Institute of Plumbing and Heating Engineering, or an approval scheme, means someone has a complaints route above the trader. Public liability insurance matters if work goes wrong in your home. A registered company number lets you look up the business on Companies House.

Questions worth asking before you book

• Are you Gas Safe registered, and what is your licence number? (For any gas work.)
• Is the quote fixed, or an estimate that could change?
• What is the call-out charge, and is it deducted from the final bill?
• Does the price include parts, VAT and removing the old unit?
• What guarantee applies to the labour, and how long does it run?
• Who will actually do the work: you, or a subcontractor?
• Do you have public liability insurance?

Comparing quotes properly

Costs vary widely by region, by the age and accessibility of your system, by whether parts are readily available, and by whether the job is an emergency. That is why a headline hourly rate tells you very little on its own.

Ask for quotes in writing, itemised into labour, parts and VAT, and make sure each covers the same scope of work. A cheaper quote that excludes making good, disposal or a new part is not cheaper. If one quote is dramatically lower than the others, ask what it leaves out before assuming it is a bargain.

Emergency call-outs

Emergency rates are higher, and reasonably so. What matters is knowing the terms before the engineer arrives: the call-out fee, the minimum charge, what counts as out of hours, and whether the fee covers any work at all or only the visit.

If you smell gas, do not wait for a plumber. Call the National Gas Emergency Service on 0800 111 999, turn off the supply at the meter if you can reach it safely, open windows and leave the property.

Paperwork to keep

• The written quote and the final invoice.
• A Building Regulations compliance certificate for a new boiler installation.
• The manufacturer warranty, which often requires annual servicing to remain valid.
• The engineer name and Gas Safe licence number for any gas work.