Most CHERUB agents retire at age seventeen or eighteen. Some who grow up quickly and look older than their years may retire earlier. A few, who have been assigned to an unexpectedly lengthy mission, have served until they are nineteen or twenty years of age.

Retired CHERUB agents are strongly discouraged from entering the intelligence service or police force, as there is a chance that these jobs may bring them into contact with criminals they came into contact with when working undercover for CHERUB.