Presented are embodiments of a modular transport robot for transporting consignments. The transport robot includes at least one base element for the structure of the transport robot, at least two expansion modules for the technical equipping of the transport robot, at least one consignment box for receiving consignments, and at least one control device. The base element and each of the expansion modules have corresponding connecting elements and are electrically connected to one another by an electrical connection. The base element has at least one wiring harness for electrically connecting the connecting elements of the base element to one another, and the base element and the expansion modules are designed correspondingly to one another such that the connecting elements of the expansion modules are selectively connectable directly to at least two connecting elements provided at different points, so as to form one common connection to the base element.