Apply for this licence

Start now on the Drinking Water Inspectorate website


You need approval from the Drinking Water Inspectorate (DWI) if you manufacture or supply some products or substances to water suppliers.

What you need approval for

You need approval for products used to treat or distribute public water. This includes:

  • construction materials that will come into contact with water intended for human consumption
  • water treatment chemicals and filtering materials not covered by a British or EU standard

This includes private drinking water supplies as well as public ones.

Products used when water has already passed into consumers’ pipes

These are regulated by the Water Regulations Advisory Scheme.

How to apply

Make sure you have:

  • read the ‘Instructions for Use’ (PDF, 180KB) document
  • asked your suppliers to provide confidential product or ingredient formulation information to the DWI (they can send this to the DWI separately)

Don’t submit applications for products still in development or you may need to make a new application if you make changes to the product.

There is a fee for making an application (currently £2,350). You may also have to pay for consultants and laboratories to test your product.