Wholesale providers

New appointments and variations (NAVs) are companies that have successfully applied to become a new service provider within an existing water company’s region. Successful applicants provide water and/or sewerage services for a specific area, typically a new or large development. Here you'll find information on how the NAV regime works and how to apply to bulk supply clean water to a new development.

We offer a number of services directly to wholesale providers or NAVs with inset sites within our region.  For more information on the services available please contact your Contract and Account Management team.

NAV market interfaces and application timeline

NAV criteria

A new appointment can be granted under these three circumstances:

  • the unserved criterion: your site has no existing water or sewer connections - areas such as these are known as ‘green’ sites and locations where these connections have been destroyed or capped off are known as ‘brown’ sites
  • the consent criterion: the existing local supplier agrees to transfer your site or premises to another company
  • the large user criterion: your site uses 50 million litres of water or more per year - this also applies to new appointments for sewerage services.
For more information on how to apply for a new appointment or variation please see the Ofwat guidance.


Please fill out the form below, and the team will contact you to take you through the process and requirements for your development site. Alternatively, if you wish to discuss your application prior to submitting it, please contact Wholesale Market Services here.

NAV agreements 

A NAV (also known as an inset appointee) providing water services will need to make sure that it has access to an adequate water supply in order to serve its customers. This may be met by arranging a bulk supply from an agreed ‘point of connection’ to our water network, usually at the site boundary. Similarly, those providing wastewater services may need an agreed ‘point of discharge’ into our sewerage network.