An electrically operated aerosol-generating system comprising a device (10) and a removable cartridge (20), the removable cartridge comprising an aerosol-forming substrate, an electrically operated vapouriser, and first electrical contacts connected to the vapouriser, the device comprising a main body (11) defining a cavity (18) for receiving the cartridge, an electrical power source (14), second electrical contacts (19) connected to the electrical power source and a mouthpiece portion, wherein the mouthpiece portion (12), in a closed position, retains the first electrical contacts on the cartridge in contact with the second electrical contacts on the device. By providing a device and cartridge based system in which the device includes a main body and a mouthpiece portion, the components for the cartridge can be simplified as compared with prior cartomiser type cartridges. Using the mouthpiece portion to retain the electrical contacts on the cartridge in contact with corresponding contacts on the device allows the manner of insertion of the cartridge into the device and removal of the cartridge from the device to be made very simple, with no complex mechanical fixings required on the cartridge.