A cartomizer for a vapor provision system, the cartomizer including: a container for holding a reservoir of free liquid to be vaporized; an atomizing chamber; a porous wick extending from inside the container, through an aperture in a wall of the atomizing chamber, to inside the atomizing chamber in order to convey the liquid from the reservoir to the inside of the atomizing chamber for vaporization; and a resilient seal provided in the aperture to restrict the liquid from entering the atomizing chamber from the reservoir except by travelling along the wick.