All too common is the assumption that because a company’s policies comply with Federal law, and perhaps other states’ laws, the policy should be fine under California law. This wrong assumption is clearly illustrated by a recent study by Expedia that estimates employees forfeit $34.3 billion in unused vacation time across the U.S. From what I’ve read, I do not see any adjustment in the study for the fact that such use-it-or-lose-it vacation policies are illegal under California law.
California law is clear that while paid vacations are not required, if a California employer provides for paid vacations, these benefits are considered wages and are earned by the employee on a pro rata basis for each day of work. Moreover, because vacation is a form of deferred wages and vests as it is earned, vacation wages cannot be forfeited – so no "use-it-or-lose-it" policies. An employer can place a reasonable cap on vacation benefits that prevents an employee from earning vacation over a certain amount of hours, and the Division of Labor Standards Enforcement has opined that a cap that allows at least nine months for the employee to use the vacation after the vacation was earned is a reasonable cap. See DSLE Enforcement Policies and Interpretations Manual section 220.127.116.11. Moreover, Labor Code section 227.3 requires that when an employment relationship ends all vacation earned but not yet taken by the employee must be paid at the time of termination.