In Finland, Universal validity of collective labour agreements is a condition that a collective agreement in an economic sector becomes a universally applicable legal minimum for any individual's employment contract, union member or not. It requires that half of the workforce in that sector support the agreement, i.e. are union members.
Workers are not forced to join a union in a specific workplace. Nevertheless, with 70% average unionization, most economic sectors are under a collective labour agreement. Notice that an agreement doesn't prohibit higher wages and better benefits, but establishes a legal minimum, similarly to a minimum wage. Furthermore, a Comprehensive Income Policy Agreement is often, but not always reached, which includes all trade unions, employer's unions and the Finnish government.