A method and apparatus for transferring communication data over power lines, the power lines comprising multiple phase transmission lines and a neutral line. The method includes inserting the communication data between multiple lines, typically between the different phase lines and the neutral, and combining the communication data from any one of the lines, and transmitting the combined signal to multiple lines in a receiving premises. In this way the signal can be picked up from any power socket at the receiving premises irrespective of what line or phase it may be attached to.