퇴직금 명목 금원의 부당이득 성립 여부 및 상계의 허부 (대상판결：대법원 2010. 5. 20. 선고 2007다90760 전원합의체 판결)

The Court ruled that monies paid to employees separate from the monthly or daily wages in the name of severance pay in accordance with a severance pay installment agreement that is void amount to unjust enrichment and that the employer is allowed to offset the employee’s claim for severance pay against the employer’s claim for unjust enrichment, limited to the portion over and above one-half (1/2) of the amount of the claim for severance pay. This ruling would serve as an important guidance for the lower courts. First and foremost, the decision reaffirmed that a severance installment agreement between an employer and an employee whereby an employer would pay an employee a specified amount of monies as severance pay along with wages paid monthly or daily, unless the agreement is recognized as a valid interim adjustment of severance pay under the Labor Standards Act, would be null and void in violation of the mandatory rule regarding the severance pay system of the Labor Standards Act because the employee would be relinquishing in advance his or her entitlement to severance pay that arises at the time of retirement. Without the Supreme Court’s explicit determination on whether monies actually paid by an employer in the name of severance pay under a void severance installment agreement, as stated above, would constitute unjust enrichment and, if they do constitute unjust enrichment, whether it is permissible to offset the claim for employee’s claim for severance pay against employer’s claim for unjust enrichment, there exist inconsistencies in the case law in the courts below and disorder in practice. Therefore, a clear judgment from the Supreme Court was strongly called for in order to unify the inconsistent practices of the lower courts by providing them with guidelines. In this light, the decision holds its significance in that it clarified the Court’s opinion that regarding the said issue the monies actually paid by an employer to an employee along with the monthly or daily wages in the name of severance pay in accordance with a severance installment agreement that is void would not constitute severance pay nor wages but would constitute unjust enrichment, which the employee shall return the employer, and further that the offset of the employee’s claim for severance pay by the employer’s claim for the said unjust enrichment is limited to the portion in excess of the one-half (1/2) of the claim for severance pay. Nonetheless, even following the holding which applied the theory of unjust enrichment with respect to the legal nature of the said monies in the name of severance pay, determination would be due on the existence of a severance installment agreement between the employer and the employee which stipulates on the payment of severance pay distinct from wages and on the existence of payment of monies in the name of severance pay distinct from monthly wages. The criteria forsuch determination are yet to be developed and defined by future decisions of the lower courts as well as those of the Supreme Court reviewing the former.