The most important document in our activity. Regulation (EC) No 261/2004 of the European Parliament and of the Council of 11 February 2004, or in short EC 261, ascertain general rules on compensation and assistance to passengers in the event of flight delays and flight cancellations. This document was created to provide a high level of protection of passengers and their rights, as well as to reduce passengers’ problems and inconveniences caused by long delays or cancellations.