A bargaining unit
in labor relations
is a group of employees with a clear and identifiable community of interests who are (under U.S. law) represented by a single labor union
in collective bargaining
and other dealings with management. Examples would be "non-management professors"; "law enforcement professionals"; "blue-collar workers"; "clerical and administrative employees"; etc. Geographic location as well as the number of facilities included in bargaining units can be at issue during representation cases.
The size of a company does not relate to the size of a bargaining unit. Bargaining units must consist of at least 3 employees, and must have the support of a majority of employees in the bargaining unit. However, the bargaining unit could be a small portion of a large company, where no other employees are members of a union.