How to Hire a Plumber
Written by James Walker · Last reviewed 15 August 2026
James Walker has 2 degrees in construction (BSc (Hons) Building Surveying · MSc Environmental Design of Buildings) and an extensive background in issue resolution, resolving over £4 billion of consumer issues.
The short answer
- General plumbing is not a regulated trade. Anyone can call themselves a plumber.
- Anything involving gas legally requires Gas Safe registration, that is a different qualification.
- Unvented hot water cylinders require a specific qualification. Ask for it.
- Emergency call-outs are where overcharging concentrates. Agree the basis of charge before they travel.
- Establish hourly rate or fixed price up front, including what happens to parts and call-out time.
On this page
What makes hiring a plumber different
There is no licence for general plumbing. Unlike gas or notifiable electrical work, most plumbing carries no legal registration requirement. Competence varies enormously and nothing external signals it.
The second difference is urgency. Most plumbers are hired calmly for planned work, but a significant share are hired in a crisis, water coming through a ceiling at ten at night. That is the worst possible position from which to negotiate, and it is exactly where inflated charging happens.
Qualifications that do matter
Gas Safe registration is legally required for gas work. A plumber is not automatically gas qualified, and many are not.
Unvented hot water cylinders require specific qualification to install or service. If your system has a sealed cylinder, ask directly.
Water regulations apply to how plumbing systems connect to the mains supply. A competent plumber will know them; ask if anything unusual is proposed.
Emergency call-outs
Before they travel, establish: the call-out charge, whether it includes any labour, the hourly rate after that, how parts are charged, and whether out-of-hours rates apply.
Get it by text if you can. A five-line message costs nothing and removes the argument later.
If water is actively escaping, find your stopcock and turn it off first. That converts an emergency into a job you can arrange properly in daylight.
Deposits and payment stages
For small work, no deposit should be needed, materials are inexpensive and readily available. For a bathroom or full system replacement, around 10% is reasonable.
Hold the final 10% until the system has run for a week. Slow leaks at joints are the classic plumbing failure, and they do not show up on the day.
What usually goes wrong
- Emergency charges far above what was implied on the phone
- Hourly work with no cap, expanding to fill the day
- Leaks appearing days later at joints made under time pressure
- Damage from the original leak disputed as pre-existing
- Gas work carried out by someone not Gas Safe registered
Questions to ask
- Are you Gas Safe registered, and is this job gas work?
- Are you qualified for unvented cylinders?
- Is this hourly or fixed price, and what does that include?
- What is the call-out charge and does it cover any labour?
- How are parts charged, at cost, or with a markup?
How it works
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