Definition - What does Union Shop mean?
A union shop is a business that allows non-union employees to be hired. However, if the business does hire a non-union member, then the person must become a union member within a certain time frame. If the person does not, then the company can be legally required to fire the person.
Justipedia explains Union Shop
Union shops are an alternative to closed shops. Closed shops are businesses that are only permitted to hire people who are already members of a union. If a person gets hired by a union shop business, then he or she typically has 30–60 days to join the union, or else faces getting fired from the position.
Employees often form unions in order to consolidate and strengthen their bargaining power within the workplace. Typially, union members must pay dues to the union.