A modular box assembly includes a box, the box defining a top end and a bottom end disposed opposite from the top end, the box including a plurality of side panels extending between the top end and the bottom end, the plurality of side panels at least partially defining a box cavity within the box; and an inner box positioned within the box cavity, the inner box dividing the box cavity into a first sub-compartment and a second sub-compartment, the inner box including a channel tab extending outward from a side panel of the inner box, the channel tab engaging a first side panel of the plurality of side panels of the box.