A toner cartridge according to one example embodiment includes a housing defining a reservoir for containing toner. An exit port in fluid communication with the reservoir faces downward on a front of the housing near a first side of the housing. A first alignment guide is positioned on the first side of the housing and a second alignment guide positioned on the second side of the housing. A toner delivery system for transferring toner from the reservoir out of the exit port includes a main interface gear. A portion of the main interface gear is exposed on the front of the housing at a second side of the housing above the second alignment guide. A connector on the first side of the housing has a forward facing opening positioned above the first alignment guide. Electrical contacts are positioned within the connector and are accessible through the forward facing opening.