Method for location-independent electricity withdrawal and/or location-independent feeding in of electricity by a mobile storage and consumption unit at a stationary charging station of an arbitrary station operator, wherein a plurality of charging stations (T1 - Tn) are supplied with electricity by a station supplier via electricity supply lines of at least one electricity distribution network operator and at least the following method steps are carried out: - establishing a first communication connection for transmission of a first data packet between the storage and consumption unit and the charging station when the mobile storage and consumption unit spatially approaches the stationary charging station, wherein the storage and consumption unit is assigned a unique identification number, which allows for an allocation to a customer supplier, and the charging station carries at least one electricity meter with a meter number; - transmission of a second data packet comprising at least the identification number and the meter number via a second communication connection between the charging station and a billing server, wherein the billing server is allocated to a station operator; - allocation of the storage and consumption unit to a customer supplier by means of the first data packet transmitted by the mobile storage and consumption unit; - transmission of a third data packet, comprising at least the identification number and the meter number, to a customer billing server at which the storage and consumption unit is registered via a further communication connection between the billing server and the customer billing server; - activation of the charging station after successful allocation and approval by the customer billing server; - delivery of electricity to the storage and consumption unit or feeding in of electricity from the storage and consumption unit to the charging station via a charging cable or via non-contact, preferably inductive or capacitive, electricity transmission; and - transmission to the billing server of the amount of electricity withdrawn from or fed into the charging station by the storage and consumption unit via the second communication connection; wherein there exists a roaming agreement between the station operator and the customer supplier; and wherein the entire electricity consumption of the charging station is registered in the charging station by means of a further electricity meter. - establishing a first communication connection for transmission of a first data packet between the storage and consumption unit and the charging station when the mobile storage and consumption unit spatially approaches the stationary charging station, wherein the storage and consumption unit is assigned a unique identification number, which allows for an allocation to a customer supplier, and the charging station carries at least one electricity meter with a meter number; - transmission of a second data packet comprising at least the identification number and the meter number via a second communication connection between the charging station and a billing server, wherein the billing server is allocated to a station operator; - allocation of the storage and consumption unit to a customer supplier by means of the first data packet transmitted by the mobile storage and consumption unit; - transmission of a third data packet, comprising at least the identification number and the meter number, to a customer billing server at which the storage and consumption unit is registered via a further communication connection between the billing server and the customer billing server; - activation of the charging station after successful allocation and approval by the customer billing server; - delivery of electricity to the storage and consumption unit or feeding in of electricity from the storage and consumption unit to the charging station via a charging cable or via non-contact, preferably inductive or capacitive, electricity transmission; and - transmission to the billing server of the amount of electricity withdrawn from or fed into the charging station by the storage and consumption unit via the second communication connection;