According to the statutes of October 2014, the cultural promotion tax of the city of Cologne must be paid by everyone who stays overnight in accommodation in Cologne. It amounts to 5% of the accommodation price and is collected by us together with the accommodation price and paid to the city.
More information and official forms are available at http://www.stadt-koeln.de/politik-und-verwaltung/finanzen/kulturfoerderabgabe