Citizenship by birth

The cover of a biometric Czech passport

The principle of jus sanguinis is used to determine eligibility for citizenship, as is typical in Europe. In principle, any person born to a Czech citizen is a Czech citizen at birth. If both grandparents on someone's maternal lineage or paternal lineage, Czech nationality will be transmitted down to the family lineage up till grandchildren. Whether a person is born in the Czech Republic or elsewhere is irrelevant. Where only the father is Czech, and the parents are unmarried, proof of paternity is required — by the parents making a concerted declaration before the Registry Office or a court, submission of a DNA test, or a court determination relating to the paternity of the child.

Children born in the Czech Republic to non-Czech parents do not acquire Czech citizenship unless:

• the parents are stateless; and
• at least one parent is a legal resident of the Czech Republic (i.e. that they are permitted to reside in the Czech Republic for more than 90 days).

Abandoned children aged less than 15 years found on the territory of the Czech Republic (where the identity of the parents cannot be established) are deemed to be Czech citizens.^[4]

Naturalization

Resident foreigners or stateless persons who have held a right of permanent residence for at least five years (reduced to three years for EU citizens) and have resided in the Czech Republic for most of that time can apply for Czech naturalization if they can prove they are of good character and are proficient in Czech (current or former Slovak citizens are exempt from language requirements). Parents can apply for their children under 15 years of age, and naturalization occurs at the discretion of the Interior Ministry.

The residence requirement can be waived if the person has a permanent residence permit and

• Has lived there for at least 10 years continuously, or
• Was born on the territory of the Czech Republic, or
• Has held Czech or Czechoslovak citizenship before, or
• At least one of his or her parents is a Czech citizen, or
• Was adopted by a Czech citizen, or
• His or her spouse or registered/civil partner is a Czech citizen, or
• Is under 18 years of age, or
• Is stateless or has refugee status in the Czech Republic.,^[5] or
• Is applying for naturalization by Section 16 and whose grant of citizenship would be a significant benefit to the Czech Republic from a sports, scientific, cultural, or other perspective

Declaration

If a person was a citizen of the Czech and Slovak Federative Republic as of 31 December 1992, he may declare citizenship of either the Czech Republic or Slovakia (gaining Slovak citizenship) assuming he does not have any other citizenship. The Slovak provision allowing for this grant expired in 1993, however, the Czech equivalent remains in the citizenship law.

The children and grandchildren of former Czech or Czechoslovak citizens who lost their citizenship on or before 31 December 2013 are also eligible to claim citizenship by declaration, also known as citizenship by descent.^[6]

Since the new amendment allowing children and grandchildren to renew their Czech citizenship through the descent route was enacted in September 2019, only about 280 children or grandchildren have taken advantage of the fast-track citizenship as of April 2021. This in spite of over an estimated 1 million Czech descendants living in the United States and an estimated 100,000 or more being eligible for the citizenship.^[7]

Due to the fact that Czechoslovakia and the United States had a treaty that forbade dual nationality for those who were naturalized in the other country at the age of 21 or older, the new citizenship by descent (declaration) mainly concerns US citizens with Czech ancestry, as it is easy to prove loss of citizenship with a US naturalization certificate. Before 1993, simply naturalizing in another country did not automatically mean loss of citizenship unless the individual who lost it was at least 21 years and naturalized in the United States or was a minor child whose US citizenship was derived from his/her parents who naturalized in the United States.^[8]

If an individual with Czech ancestry has ascendants who naturalized in a country other than the United States and is thus unable to prove loss of citizenship by naturalization due to a lack of a treaty between their country and Czechoslovakia that restricted dual citizenship, they may be eligible for Czech citizenship by proving a loss of an ancestor's citizenship by other means. One such way could be if their ancestor was a grandmother who married a non-Czechoslovak citizen before 24 June 1947, in which case their grandmother would have automatically lost Czechoslovak citizenship ipso iure due to the Emigrant Patent of Austrian Law from 1832. The proof of loss of citizenship in this case would be the grandmother's marriage certificate.^[9]

Voluntary (restrictions on dual citizenship)

Czech citizenship can be renounced voluntarily if doing so wouldn't cause one to be stateless unless it is in connection with a marriage or by birth – the Czech Republic does not require children born with another nationality to renounce it upon reaching maturity.

Involuntary

The involuntary loss of citizenship is constitutionally prohibited. However, before the 2013 Citizenship Act (effective as of 1 January 2014) it was sometimes argued by emigrants and emigrant groups that the restrictions on dual citizenship were a form of involuntary deprivation of citizenship.^[10]

During the communist era (1948–89) hundreds of thousands of Czechoslovakian citizens had emigrated into other parts of the West. The regime punished emigration by removing Czechoslovak citizenship, along with property confiscation and in absentia prison sentences. Since the Velvet Revolution in 1989, many emigrants demanded their citizenship be restored. Between 1999 and 2004, a special measure allowed them to regain the citizenship,^[11] but a few people took advantage of the wording, which "granted" citizenship rather than "restored" it and so got dual citizenship. A few people from Volhynia and Romania also got citizenship.