According to the Ministry of Foreign Affairs (MFA), the longer name Czech Republic must be used only in official government documents, in the names of embassies, official correspondence, etc.
The Czechia brand should be used in all other cases. Among other things, it is more practical and less formal. As a shorter version of our country's marking, it fits better signs accompanying official meetings at the highest political level or meetings of international organizations, as well as promotional materials such as large advertising signs at trade fairs. Czechia also works better in informal communication and correspondence as well as in literary works, newspaper articles, etc. It is similar with the jerseys and other clothing of people representing the state in culture, science, sports and other spheres. For example, the Czech Olympic Committee has already switched to the short version - Czechia.
To sum up the Czechia brand should be used for press coverage and other materials presenting domestic achievements, history or personalities of the country. This applies to promotional printed materials and items as well as to private entities.