Trade unions may operate at warious levels:

• trade union organization (workplace trade union) operates within a single employer. Such an organisation has the statutory rights of a trade union if it has at least 10 members performing paid work for that employer. If these persons are not employees, only those who have worked for the employer for at least six months are counted towards the required number of 10,
• multi-employer trade union organization represents employees of at least two employers. As a general rule, the provisions concerning workplace trade union organisations also apply to such organisations. This solution allows employees of small workplaces, for example, workplaces with only a few employees to benefit from trade union representation where it would not otherwise be possible to establish a workplace organisation,
• multi-workplace trade union organization covers structures operating across multiple employers within a particular industry, profession, region or throughout the country. It may take the form of a nationwide trade union, an industry trade union or a regional organisation,
• A federation of trade unions uniting independent trade unions. The individual unions retain their separate legal and organisational identity, but entrust the federation with representing their common interests at a higher level, 
• Confederation of trade unions – brings together trade unions and federations.  It is the broadest organisational structure, capable of operating at the national level, participating in social dialogue and giving opinions on draft legislation. Therefore, a larger union may represent employee not only from single workplace, but also from larger groups of employees or a specific sector.