The ESB is to change its billing system next month.
It comes as full de-regulation in the electricity market formally commences on February 19, 2005.
Christine Quinn, Press Officer for ESB consumer services, said: “Whereas previous customers would be familiar with having one account number from January of next year they will have two.”
“They will have their supply account number which relates to their actual bill and level of consumption and a network symbol which relates to the presence of the meter in their home.”