New Appointments and Variations (NAVs)

What is a NAV?

New appointments and variations (NAVs) are limited companies which provide a water and/or sewerage service to customers in an area which was previously provided by the incumbent monopoly provider.

A new appointment is made when a limited company is appointed by Ofwat to provide water and/or sewerage services for a specific geographic area. A new appointee has the same duties and responsibilities as the previous statutory water company.

A variation is where an existing appointed company (an “appointee”) asks Ofwat to vary its appointment so it can extend the areas it provides services to.

A NAV, therefore, involves one company replacing another as the appointee for a specific geographic area.

More information can be found about getting a new appointment or variation.


NAV web graphic


This picture illustrates how a new appointee’s area of appointment could relate to that of existing appointees.

NAVs provide competition in a market which is inherently monopolistic. This can provide a number of benefits for society, end-customers and developers. The benefits include serving a site at a lower cost, facilitating multi-utility developer service and encouraging innovation.

The scale of the market is relatively modest. Because of the wide range of benefits NAVs provide, we are actively encouraging an effective market through evidence-based policy. We have published a number of policy initiatives and documents with this aim, they can be found in the NAV publications section of the website.

List of NAVs and further information

A list of NAV appointees and our table of relevant NAV documents and links can be found in the boxes on the left-hand side of this page.

Maps of company boundaries

Ofwat produces a digital representation of the water and sewerage undertaker boundaries as GIS shapefiles. The shapefiles are designed for geospatial analysis only. The definitive legal record of water supply and sewerage services areas remains the maps and other information set out in the appointments of companies as water and/or sewerage undertakers and subsequent area variations.

For a copy of the NAV boundaries as GIS shapefiles please email us at [email protected].

You can also download the shapefiles from the  House of Commons Library website.

The GIS shapefiles have been digitised from the legal records by Ofwat with support from Ordnance Survey. They are published under the Open Government Licence.