A washing machine appliance defines a mutually perpendicular vertical direction, lateral direction, and transverse direction. The washing machine appliance includes a cabinet and a top cover. A wash tub is mounted within the cabinet and a wash basket is mounted rotatably within the wash tub. The wash basket is accessible through an opening in the top cover. A bulk tank is mounted inside the top cover. The washing machine appliance further includes a dispensing pump spaced apart from the bulk tank and in fluid communication with the bulk tank. The dispensing pump is operable to draw a liquid additive from the bulk tank. The washing machine appliance also includes a dispenser box downstream of the dispensing pump and upstream of the wash tub.