Investigation into whether Thames Water is contravening the Competition Act 1998

Case summary: updated 9 July 2020

On 21 June 2019, we opened an investigation into allegations that Thames Water Utilities Limited has contravened the prohibition in Chapter II of the Competition Act 1998 (“CA98”) by abusing a dominant position. The allegations relate to:

  • the approach that Thames Water has taken when installing digital smart meters and the impact that this has had on providers of data logging services and their customers
  • the accuracy of the data about customers that Thames Water made available to retailers at the time of the opening of the business retail market
  • the fairness of certain contractual credit terms that Thames Water applies to retailers

As part of our on-going analysis we keep under review which of our regulatory tools are most appropriate to each of the issues being considered. On the basis of our assessment, we no longer consider that the CA98 is the most appropriate tool to use in relation to the allegation about contractual credit terms. We consider that this can be more effectively considered using our powers under sections 66DA and 117F of the Water Industry Act 1991 in relation to compliance with the Wholesale Retail Code. We have therefore now split this out into a separate investigation. We continue to progress the other strands of our investigation under the CA98.

Date opened

21 June 2019

Relevant powers

Chapter II of the Act




We opened this case after carrying out a preliminary assessment of the complaint and having given consideration to our prioritisation principles.

We have sought and obtained agreement from the Competition and Markets Authority that it is appropriate for us to exercise our concurrent functions under the Act to investigate the allegations.

We will gather information from a number of parties and assess this with a view to identifying whether Thames Water has abused a dominant position.

Further details on the processes that we will follow can be found in our guidance on the application of the Act to the water and wastewater sector.


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