In accounting for compensated absences, the difference between vested rights and accumulated rights is that:

vested rights carry a stipulated dollar amount that is owed to the employee; accumulated rights do not represent monetary compensation.

vested rights are a legal and binding obligation on the company, whereas accumulated rights expire at the end of the accounting period in which they arose.

vested rights are normally for a longer period of employment than are accumulated rights.

vested rights are not contingent upon an employee's future service.