A toner cartridge (100, 400) for use in an image forming device comprising: a housing (102, 402) having a top (106, 406), a bottom (108, 408), a front (114, 414), and a rear (116, 416) positioned between a first side (110, 410) and a second side (112, 412) of the housing (102, 402), the housing (102, 402) defining a reservoir for containing toner therein, the housing (102, 402) having an elongated shape between the first side (110, 410) and the second side (112, 412); an exit port (152, 452) in fluid communication with the reservoir and facing downward on the front (114, 414) of the housing (102, 402); a shutter (154, 509) positioned at the exit port (152, 452) that is movable between an open position to permit toner to pass out of the exit port (152, 452) and a closed position to prevent toner from passing out of the exit port (152, 452); a toner delivery system for transferring toner from the reservoir out of the exit port (152, 452) that includes a main interface gear (130, 430) for providing rotational power to the toner delivery system, characterized by the exit port (152, 452) being located near the first side (110, 410), a portion of the main interface gear (130, 430) being exposed on the front (114, 414) of the housing (102, 402) near the top (106,406) of the second side (112, 412) and engagable with a corresponding drive gear in the image forming device; a rearward facing opening (175, 475) exposed at the rear (116, 416) of the housing (102, 402) near the first side (110, 410) of the housing (102, 402) and extending from the rear (116, 416) of the housing (102, 402) toward the front (114, 414) of the housing (102, 402) for receiving a first engagement feature (210, 510) in the image forming device for opening and closing the shutter (154, 509); and a forward facing opening (174, 474) exposed at the front (114, 414) of the housing (102, 402) near the first side (110, 410) of the housing (102, 402) and extending from the front (114, 414) of the housing (102, 402) toward the rear (116, 416) of the housing (102, 402) for receiving a second engagement feature (210, 510) in the image forming device for locking and unlocking the shutter (154, 509). a housing (102, 402) having a top (106, 406), a bottom (108, 408), a front (114, 414), and a rear (116, 416) positioned between a first side (110, 410) and a second side (112, 412) of the housing (102, 402), the housing (102, 402) defining a reservoir for containing toner therein, the housing (102, 402) having an elongated shape between the first side (110, 410) and the second side (112, 412); an exit port (152, 452) in fluid communication with the reservoir and facing downward on the front (114, 414) of the housing (102, 402); a shutter (154, 509) positioned at the exit port (152, 452) that is movable between an open position to permit toner to pass out of the exit port (152, 452) and a closed position to prevent toner from passing out of the exit port (152, 452); a toner delivery system for transferring toner from the reservoir out of the exit port (152, 452) that includes a main interface gear (130, 430) for providing rotational power to the toner delivery system, characterized by the exit port (152, 452) being located near the first side (110, 410), a portion of the main interface gear (130, 430) being exposed on the front (114, 414) of the housing (102, 402) near the top (106,406) of the second side (112, 412) and engagable with a corresponding drive gear in the image forming device; a rearward facing opening (175, 475) exposed at the rear (116, 416) of the housing (102, 402) near the first side (110, 410) of the housing (102, 402) and extending from the rear (116, 416) of the housing (102, 402) toward the front (114, 414) of the housing (102, 402) for receiving a first engagement feature (210, 510) in the image forming device for opening and closing the shutter (154, 509); and a forward facing opening (174, 474) exposed at the front (114, 414) of the housing (102, 402) near the first side (110, 410) of the housing (102, 402) and extending from the front (114, 414) of the housing (102, 402) toward the rear (116, 416) of the housing (102, 402) for receiving a second engagement feature (210, 510) in the image forming device for locking and unlocking the shutter (154, 509).