How to Choose a Plumber: A UK Checklist
General plumbing in the UK is an unregulated trade — anyone can call themselves a plumber — so the vetting burden sits with you, and the difference between a professional and a chancer shows up in exactly the checks most people skip. The good news: five questions and ten minutes of verification separate them reliably. This is the checklist we apply to every plumber in our own network.
Qualifications and the regulated islands
Look for recognised trade qualifications (NVQ/SVQ Level 2–3 in plumbing, or long-standing time-served experience with evidence) as the baseline. Then match the job to the regulated islands within plumbing: unvented cylinder work legally requires G3 certification; anything touching gas is Gas Safe territory (a separate register you can search online); electrical work alongside plumbing needs a qualified electrician.
Membership of CIPHE (the professional body) or WaterSafe/APHC (approved contractor schemes) isn't mandatory but signals a plumber who's opted into standards and oversight — worth weight in a tiebreak.
Insurance, and why you insist
Public liability insurance (£2m+ is standard) is the non-negotiable: it's what pays when a soldering job meets a joist badly or a fitting lets go overnight. A professional carries it as unremarkably as tools and will confirm without friction; hesitation at the question is a complete answer.
For larger jobs, ask about workmanship guarantees in writing — 12 months on labour is a reasonable norm — and whether parts carry manufacturer warranties (fitted-by-certified conditions apply to some, notably unvented kit).
Quotes that protect both sides
A quality quote is written, itemised (labour, parts, any call-out or minimum, VAT status) and states what's excluded — making good, disposal, unforeseen access. For hourly work, the rate, the minimum and the parts-markup basis should be explicit before anyone travels. Compare quotes on scope, not just the bottom line: the cheap quote that excludes reinstatement isn't cheap.
Payment structure is a character reference: small jobs settle on completion; larger jobs stage payments against progress. Full payment upfront is a red flag with few exceptions (special-order kit deposits are legitimate).
Reviews, red flags and the two-minute phone test
Read reviews for patterns rather than scores — repeated mentions of punctuality, tidiness, honest pricing and fixed-first-time carry more signal than star averages, and how a firm answers its critical reviews tells you how it'll handle your problem. Local reputation (neighbours, community groups) still outperforms most platforms.
Red flags to act on: cash-only insistence, no traceable address or landline history, pressure tactics ('price only good today'), vagueness on insurance or quals, and doorstep cold-calling after 'noticing a problem'. And the two-minute phone test works: describe your fault and listen — a pro asks diagnostic questions, gives a realistic range and explains the pricing model unprompted. Vagueness on all three at quote stage becomes vagueness on the invoice.
| Check | Pass looks like | Fail looks like |
|---|---|---|
| Qualifications | NVQ/time-served; G3/Gas Safe as needed | Evasive, 'no need' |
| Insurance | £2m+ PL confirmed readily | Hesitation |
| Quote | Written, itemised, exclusions stated | Verbal, round number |
| Reviews/reputation | Consistent patterns, answered criticism | None traceable |
| Payment | On completion / staged | All upfront, cash-only |
Timing the change well
Decisions like this have natural moments: replacement time (when something has failed anyway), renovation time (when access is open and trades are on site), and pre-failure time (when the incumbent is old enough that acting on your schedule beats reacting on its). The expensive moment is mid-emergency, choosing under pressure with no time to compare. If your current setup is ageing, deciding now — even if executing later — is the cheap insurance.
Frequently asked questions
Are plumbers regulated in the UK?
General plumbing isn't — no licence is required — which is why vetting matters. The regulated islands are gas (Gas Safe, legally required), unvented hot water (G3) and associated electrics. Approved-contractor schemes like WaterSafe are voluntary quality signals.
Should I always get three quotes?
For substantial work, yes — not to chase the lowest but to triangulate scope and price. For small repairs, one well-vetted plumber with clear pricing beats three quotes' worth of delay; that's the gap our vetted network exists to fill.
What's a fair deposit for plumbing work?
Small jobs: none — pay on completion. Larger installs: staged payments tied to milestones, with any deposit proportionate to special-order materials. Walk away from full-payment-upfront regardless of the story.
The cheap quote is half the others — tempting?
Interrogate the gap: missing scope (making good, parts quality, disposal), missing insurance/quals, or a business that underprices and cuts corners under pressure. Occasionally it's a genuine quiet-week price — the vetting checklist tells you which you're looking at.
Sorting it for good
The recurring theme across our guides holds here too: fix causes, not symptoms. A repair that addresses why the fault happened — the pressure that's too high, the scale that keeps returning, the valve that should have been replaced a decade ago — is the one you don't repeat next year. When you book through our network, tell the engineer you want the cause addressed, not just the symptom silenced; it occasionally costs a little more on the day and reliably costs less over the years.