Thames Water approved contractor: what a WaterSafe approval actually is

Someone has told you to use a Thames Water approved contractor. It may have arrived in a leak notice, from a neighbour, or written on a plumber's quote. The phrase is doing a lot of work, and part of it is out of date.

There is no Thames Water badge to look for any more. A January 2022 fact sheet from the Approved Contractors Forum listed seven separate approved contractor schemes, among them TAPS operated by Thames Water, APLUS operated by Anglian Water and WaterMark operated by Severn Trent Water. Water Regs UK now lists four schemes, and TAPS is not one of them. Thames Water's own find a plumber page tells customers to choose a WaterSafe approved contractor, and the contact WIAPS publishes for Thames Water's approved plumber scheme is a WIAPS email address, not a Thames Water one.

So the honest translation of "you need a Thames Water approved contractor" is: you need someone on the WaterSafe register, and in London that almost always means WIAPS. Here is what that actually involves, what it protects you from, and what it does not.

WaterSafe is a search box, not a qualification

Nobody is approved by WaterSafe. The Approved Contractors Forum fact sheet says it plainly: WaterSafe "is an umbrella brand to allow members of the seven Approved Contractors schemes to be found on the WaterSafe website", and it "does not administer membership applications, membership renewals, audits or complaints".

WaterSafe is the shop window. It runs the website, the postcode search and the consumer campaigns. The approval itself happens inside one of the schemes behind it, and so does the auditing and the complaints handling. That distinction matters the moment something goes wrong, because it tells you who to ring.

The four schemes behind the window

Water Regs UK currently lists four approved contractor schemes:

• WIAPS, the Water Industry Approved Plumbers' Scheme, operated by Water Regs UK "on behalf of 18 water undertakers". This is the route for London.
• APHC, the Association of Plumbing and Heating Contractors, operating in England and Wales.
• CIPHE, the Chartered Institute of Plumbing and Heating Engineering, operating UK wide.
• SNIPEF, covering Scotland and Northern Ireland.

WIAPS membership is currently free for plumbers, with fees applying to the other sector schemes. That is worth knowing before you read too much into the logo. The badge is not evidence that a business invested heavily in it.

What a business has to do to get approved

The joining requirements are short and specific. An approved contractor must hold an appropriate water fittings regulations qualification, and an approved plumber must also hold a recognised plumbing qualification. The business must carry appropriate insurance; WaterSafe requires every registered business to hold public liability cover of at least GBP 2 million, and employers' liability cover where it applies. On completion of work the contractor must issue a certificate stating whether that work complies with the regulations.

Then there is the part that gives the scheme any teeth at all. In WIAPS's own words, "You must also make yourself available to be periodically audited by the local water company." Nobody inspects every job. The scheme works by sampling.

What approval actually buys you

Two things, and both are narrower than the marketing suggests.

It removes the notification requirement on exactly three items

Regulation 5 of the Water Supply (Water Fittings) Regulations 1999 lists work you must notify to your water company before you start. You must not begin without consent, though consent "shall not be withheld unreasonably", and if the company has not replied within ten working days consent is deemed to have been granted unconditionally.

The list includes installing a bath over 230 litres, a pump or booster drawing more than 12 litres a minute, a reverse osmosis unit, an automatic garden watering system, and "any water system laid outside a building and either less than 750mm or more than 1350mm below ground level".

Regulation 5(2) then says the regulation "does not apply to the installation by an approved contractor of a water fitting falling within paragraph 2, 4(b) or 4(g) in the Table". That is three items: altering a water system on premises other than a house, a bidet with an ascending spray or flexible hose, and a reduced pressure zone valve assembly.

Read that again against the depth rule. If your underground supply pipe is replaced at a depth outside 750mm to 1350mm, that is notifiable work and being an approved contractor does not exempt it. A firm telling you that its approval means no paperwork is either simplifying or wrong. This comes up constantly on London properties where the run crosses a shallow patio or a deep basement lightwell, which is exactly where garden and driveway leaks tend to sit.

It gives the householder a legal defence

Contravening the notification and consent provisions is an offence under regulation 7, punishable on summary conviction by a fine not exceeding level 3 on the standard scale. Separately, under section 73 of the Water Industry Act 1991, an owner or occupier whose water fitting causes water to be contaminated, wasted or misused commits an offence.

Regulation 8 provides a defence to that second charge. It requires proof that the works were carried out by or under the direction of an approved contractor, and that the contractor "certified to the person who commissioned those works that the water fitting complied with the requirements of those regulations".

Note who is being protected. The defence belongs to you, the owner or occupier, and it only exists if the certificate exists. If a contractor tells you he is approved but never issues the certificate, you have paid for the badge and received none of the protection. Ask for the certificate at the point of quoting, not after the trench is backfilled.

What the register does not tell you

The WaterSafe search offers five contractor types: plumbers, water supply pipe installers, catering installers, point of use installers, and RPZ valve testers. Leak detection is not one of them, because leak detection is not work on a water fitting and is not notifiable under the regulations. There is no approval category for it to sit in.

Approved contractors are also not approved to work on water company assets. The register covers private plumbing. If the leak turns out to be on the communication pipe or the main, that is Thames Water's to fix, whoever you have hired, and the boundary between the two pipes decides who pays.

Finally, approval is a regulations test, not a workmanship rating and not a price control. WaterSafe's own advice to customers is to get three quotes. The complaints route runs contractor first, then the approval scheme, then WaterSafe. Nothing in that chain compensates you for a bad job that happened to comply.

How to check a claim, in about two minutes

1. Search the business name and your postcode at watersafe.org.uk. The listing is free to search.
2. Match the business, not the person. Approval attaches to a registered business and a named individual, and a subcontractor on site may not be covered by the listing you found.
3. Ask to see the ID card. WaterSafe states that all approved plumbers hold an ID badge carrying the WaterSafe Register logo.
4. If anything does not line up, ring the scheme directly. WaterSafe tells customers to contact the plumber's approved contractor scheme to validate membership.

An unnumbered claim on a van or a website footer is worth nothing. Neither is a logo. The register is the only check that means anything, and it takes less time than reading the quote.

Where a leak detection survey sits in all this

We should be straight about our own position. London Leak Specialist is not on the WaterSafe register. We detect leaks; we do not install or alter water fittings, and detection is not notifiable work, so there is no certificate for us to issue and no category on the register for us to appear in. If your repair turns out to be a supply pipe replacement or anything else on the regulation 5 table, use the register to pick the firm that does that work.

There is a practical reason to establish what the fault is before you go looking for a certified trade. Across our last 400 leak detection surveys, the cause was found in 95 per cent of cases. In 2 per cent the water was coming from a neighbouring property. In 3 per cent it was not a plumbing leak at all: gutters, roofs and other structural defects letting water in. In that last group an approved plumber would have been the wrong trade entirely, and in the group before it the pipe to be repaired was not even on your side of the wall.

If you have had a letter from Thames Water about a leak and you are being asked to arrange a repair, the sequence that wastes least money is: find the leak, confirm whose pipe it is on, then hire the approved contractor for the fitting work with the scope already known.

Our standard leak detection rate is GBP 160 an hour, and a typical survey runs two to four hours, so GBP 320 to GBP 640. Heating, mains and trace and access work is GBP 200 an hour. The rate is agreed before we travel and it does not rise on the day. If we attend a confirmed live leak and cannot locate it, the detection time is not charged, which is what no find, no fee means in practice. Call 020 7123 8560 and we will tell you the likely hours before you book.

We cover London out to the M25, all 32 boroughs. Full rates are on our pricing page, and if you are still comparing firms, the questions worth asking are set out in our guide to choosing a leak detection company.