Application process

The diagram below illustrates the stages involved in the application process, and the indicative timescales for the application process.

Initial checking stage

We will only accept applications that contain all the information we require and when the application fee has been received.

As soon as reasonably practicable following our decision that we are satisfied that a complete application has been received, we will provide the applicant with written confirmation. The written confirmation will signal the start of our assessment process. We aim to notify the applicant that its application has or has not been accepted as complete within five working days of receipt of the application.

Once we are satisfied that an application is complete, we will publish a notice of the application on our website.

As part of completing the application form, applicants will be required to confirm that they consent to us sharing the information provided in its application with the Drinking Water Inspectorate (DWI), Environment Agency (EA) and Natural Resources Wales (NRW) (if applicable), to enable them to complete an assessment of the technical competency of the applicant.

How we assess applications

To assess an application, we will consider whether the applicant has the appropriate level of competency to hold a WSSL with a retail authorisation limited to self-supply. We do this by assessing a number of key areas, including managerial competency, financial stability and technical competency.

  • Managerial competency  is a key element of our assessment criteria. In particular, we look at: the skills, qualifications and experience of the applicant’s staff; whether the applicant has an adequate understanding of the duties of licensees limited to self-supply under the law and licence conditions; and the systems and procedures it has in place to comply with those duties.
  • With regards to financial stability, we consider whether the applicant has sufficient financial resources to finance its obligations under the law and to deliver its business plan and whether it has the capacity to raise funds in future if necessary to operate as a licensee limited to self-supply. The applicant should be able to demonstrate to us its understanding of the functions of a licensee limited to self-supply and the impact being a licensee will have on its financial statements.
  • Technical competency should be demonstrated relating to the measures expected by the DWI, NRW and EA – for example, knowledge of the relevant security and emergency measures required. The DWI, NRW and EA will provide an assessment of whether applicants have the technical competency required. Our guidance covers the technical information that the DWI, EA and NRW will assess as part of the application process. The DWI, EA and NRW review applications to ensure that applicants for a WSSL limited to self-supply have an overall understanding of water supply and water quality issues and the potential environmental impacts that can arise from their usage of supply systems so that licensees’ activities do not have a detrimental effect on an appointed company (the wholesaler)’s supply system.

The market operator

In order to enter the market, a self-supplier will need to make a trading application to MOSL (the market operator), complete Market Entry Assurance Certification (MEAC) and satisfy the trading conditions.

MOSL’s website provides further information on the Market Entry Assurance process. MEAC provides assurance that a company seeking to become a trading party within the retail market has the required systems, processes and capabilities to fulfil its market obligations. We expect applicants to complete the Market Entry Assurance process alongside applying for a WSSL as these processes are interdependent. As such we require certification from MOSL in order to grant a WSSL.


At the same time that an application is made, an applicant must pay an application fee (£3,000) to have its application assessed. The application fee is intended to cover the average cost incurred by Ofwat in processing each application. An application will not be processed until the application fee has been paid.

Applicants should note that there will be other costs to operating as a self-supplier including the annual fees to MOSL, costs involved in maintaining the appropriate security status to access CMOS and the general administrative costs of operating in the market and ensuring compliance with the market codes.