A locking device for a box includes a first panel defining a locking tab separable from the first panel and comprising a first tab subpanel and a second tab subpanel; the first tab subpanel extending from the first panel and the second tab subpanel extending from the first tab subpanel, the second tab subpanel including a neck and an ear, the ear extending from the neck in a lateral direction of the locking tab; and a second panel defining a locking opening, the locking opening sized to receive and capture the locking tab, the locking tab configured to engage an edge of the locking opening and thereby configured to prevent movement of the locking tab with respect to the locking opening in an opening direction of the locking device.