Firstly, on the Traveller's map, find out what rules apply to you before entering a foreign country (e.g. PCR test, quarantine, etc.) Also, check the current hygiene measures at the airport (Václav Havel Airport).
At the international airports in the Czech Republic, the obligation to wear a respirator of class FFP2 (KN 95) without an exhalation valve, or another protective means of the nose and mouth with a filtering effect of at least 94% applies. Children from 3 to 15 years of age have an exception and can wear only a medical veil, but we also recommend the use of a respirator.
Exceptions to wearing the veil have children under 2 years of age (including of) and persons with intellectual disabilities and severe mental disorders if they cannot wear the veil due to this condition.
Returning to the Czech Republic for Czech citizens
The currently valid rules of entry into the Czech Republic can be found in this life situation.
For the purpose of entering the Czech Republic, the same rules apply as for Czech citizens for family members of Czech citizens who have a temporary residence permit in the Czech Republic, for foreigners with a permanent residence permit in the Czech Republic, and for EU citizens with a temporary residence permit issued on the territory of the Czech Republic.
Other foreigners (citizens of third countries who do not have a residence permit issued by the Czech Republic or who do not have a long-term or permanent residence permit in another EU+ country and citizens of third countries who have been issued a short-term visa by the Czech Republic before 11 May 2020 and who have been issued a short-term or long-term visa in another EU+ country) are prohibited from coming to the Czech Republic for other than necessary reasons. There is a certain exception to this ban. For further information, look at Tourism in Czech.
If you are traveling for any of the above reasons, proceed according to the obligations of foreigners when entering the Czech Republic.
Duties of airport operators
Operators of public international airports in the Czech Republic are obliged to ensure random checks of passengers arriving in the Czech Republic (this applies to flights from Schengen area countries as well as from other countries). They will check compliance with the obligations for entry into the Czech Republic, as described in Possibilities and obligations of foreigners entering the Czech Republic, i.e. the documents required for entry (e.g. a completed entry form, a vaccination certificate, proof of a negative test for SARS-CoV-2 or a certificate of having contracted covid-19). Checks may be carried out in cooperation with the Police of the Czech Republic or the Customs Administration. They have access to the ISIN API framework for checks.
Persons entering the Czech Republic are obliged to present the necessary documents.
The Ministry of Foreign Affairs of the Czech Republic recommends that you secure travel insurance before your trip, including medical expenses in the event of COVID-19.
Czech airports as transit airports
If you are transiting the Czech Republic by plane and the transit does not exceed 12 hours, you are required to complete an arrival form and if you are required to be tested by the color of the country you are coming from, you must have a negative RT-PCR or antigen test result before entering the Czech Republic. If you are traveling from a country with a very high risk of infection, you may only enter for the necessary reasons described in the Tourism in the Czech Republic.
Transit airports outside the Czech Republic
If you are traveling abroad and you have to change trains during your flight, look at the Traveler's map. The rules for transit should be written here. If this information is not explicitly written on the given page, contact the info line of the Ministry of the Foreign Affairs: +420 222 264 222 (available on MON-FRI from 08:00 - 16:00. Additionally, outside of this time frame there will be available basic information regarding traveling to other countries).