The COMPASS Upgrade (COMPASS-U) tokamak represents a compact, medium-size (R=0.894m, a=0.27m), high-magnetic-field (5T) and high-density device with a flexible set of poloidal field coils. It will be equipped with a closed divertor, plasma heating will be facilitated by 4MW of NBI and 4MW of ECRH. The project received funding and started at the beginning the year 2018. The conceptual design of the individual COMPASS-U systems is presented with emphasis on the technical aspects, e.g. magnets, vacuum vessel, support structure and power supply system.