Utilities are currently going through negotiations with Ofwat over what they will be able to charge bill-payers and spend on their pipes and infrastructure for 2015-20.
Seven companies are registered as water supply licensees but just one of the 2,200 eligible businesses has ever chosen to switch, Ofwat, the industry regulator, said.
The water industry has already been criticised for losing a significant amount of water through leakage, with Ofwat statistics showing 3,365 megalitres lost per day in 2010-11.
