Nostrification (the process of recognition of previous education abroad) is necessary to study at the MIAS School of Business. Nostrification process of secondary education is organized by the city of Prague, specifically by the Division of Education, Youth and Sport of Prague City Hall.
Please, see their official website for further information. See this website for further useful information.
MIAS allows the nostrification process to be completed by the end of the first year of study (so not necessarily before enrolment); however the sooner the process starts, the better, as it may take several months to complete it.