Licensing factors primarily occur in eukaryotic cells, since bacteria use simpler systems to initiate replication.
The origins are required to fire only once per cell cycle, an observation that led to the postulated existence of licensing factors by biologists in the first place.
At this point Cdc6 leaves the complex and is inactivated, by being degraded in yeast but by being exported from the nucleus in metazoans, triggered by CDK-dependent phosphorylation.
In this way their mode of action is limited to starting replication once, since once they have been ejected from the complex by other proteins, the cell enters S phase, during which they are not re-produced or re-activated.
It has been suggested that the whole pre-replication complex be called the licensing factor since the whole is required for assembling additional proteins to initiate replication.