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Guidance

Water fittings regulations: specifications approved by the regulators

Approved specifications as a way of showing compliance with relevant regulations. The specifications on this page apply from 6 May 2027.

Applies to England and Wales

Role of the regulations and specifications

The Water Supply (Water Fittings) Regulations 1999 set out the requirements for water fittings. For the public water supply, the regulations aim to:

  • prevent contamination

  • ensure efficient water use (undue consumption)

  • protect against misuse and waste

Water undertakers are responsible for enforcing the regulations.

If you have any questions about complying with the regulations, contact your local water company or Water Regs UK. Water Regs UK are funded by water undertakers to promote compliance with the regulations.

Specifications approved by the regulator

Water fitting specifications set out the legal requirements as a way to comply with the regulations. Some specifications are referred to as Test Code Sheets (TCS).

The specifications published on the Water Regs UK website apply in their current form.

Specifications applicable from 6 May 2027

From 6 May 2027, these updated specifications will apply:

From 6 May 2027, specification TCS 5011-5 Measurement of dimension, will no longer apply.

Updates to this page

Published 6 May 2026

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