An arrangement that requires an employer to hire only union members. In a closed shop, union membership is a condition of continued employment. Closed shops are illegal under federal labor law and state public employment relations acts.
An agreement between an employer and a union that, as a condition of employment, all employees must belong to the union before being hired. The employer agrees to retain only those employees who belong to a union.
A closed shop is a business or industrial establishment whose employees are required to be union members (often of a specific union and no other) as a precondition to employment. It is opposed to the open shop, which refuses either to hire workers on the basis of their union membership or to give union members preference in hiring. It is different from the union shop, which does not require employees to be union members as a condition of employment, but does require that they join the union or pay the equivalent of union dues within a set period of time following their hire, although this too is commonly referred to as a "closed shop" in the United Kingdom.