The article is devoted to the issue of the coalition in trade unions of persons employed on civil law basis. The notion of civil law employment may be understood in different ways. In the narrow interpretation (sensu stricto) it refers only to individuals who perform work under civil law agreements, such as a contract of mandate or an agreement on the provision of services. In the wider sense (sensu largo), one might also add performing work by self-employed persons (b2b). Moreover, the article discusses some aspects of the status of trade union officials performing work on a civil law basis.