A tank system for a reducing agent includes: a vessel configured to store the reducing agent, the vessel having: an upper vessel wall, lateral vessel walls, and a lower vessel wall; and a conveying device, the conveying device being configured to provide the reducing agent under pressure by way of an outlet to an exhaust gas. One or more openings are arranged in the lower vessel wall, the one or more openings forming a connection to a further volume (V) filled with reducing agent. At least one opening of the one or more openings has radially inwardly directed elements arranged on a circumference of the at least one opening.