An individual is considered resident for tax purposes in the Czech Republic if either of the following conditions is met:
The individual possesses a permanent home in the Czech Republic. The possession of a long-term visa does not itself make an individual a tax resident in the Czech Republic.
The individual is present in the Czech Republic for 183 or more days in a calendar year. This includes the days of arrival and departure.
If a foreigner is considered resident for tax purposes in the Czech Republic and at the same time he/she is a tax resident of a country with which the Czech Republic has concluded a double-taxation treaty, the determination of tax residency under the treaty applies (subject to Czech interpretation of the treaty).
Czech tax residents are taxable on their worldwide income, subject to restrictions by the applicable double taxation treaty (if any). Czech tax non-residents are generally taxable only on their Czech-source income.