The article deals with the current change in the concept of a cassation complaint filed with the Supreme Administrative Court of the Czech Republic. The Supreme Administrative Court’s core activity is deciding on cassation complaints. They challenge previous final decisions of regional courts in the administrative judiciary. An amendment was adopted in February 2021. Since April 2021, it has been introducing (or rather substantially expanding) a certain “filter” of cassation complaints. This “filter” consists of restricting access to the Supreme Administrative Court, aimed at reducing the Supreme Administrative Court’s workload through cassation complaints. The essence of this “filter” is that it will be easier for the Supreme Administrativ...