In this paper, the basic functions of an electric vehicle charging service provider are described with a focus on the associated optimization problems. A novel method of planning the charging of electric drive vehicles including electricity grid constraints, both voltage and power, is shown. The method establishes an individual charging plan for each vehicle and avoids distribution grid congestion while satisfying the requirements of the individual vehicle owners. The concepts proposed in this paper are tested on a simulated electricity grid. It is shown that both power and voltage constraints due to electric vehicle charging can be avoided using the proposed method.