If a person was a citizen of the Czech and Slovak Federative Republic as of 31 December , he may declare citizenship of either the Czech Republic or Slovakia gaining Slovak citizenship assuming he does not have any other citizenship. The law came into effect on 1 January , the date of the dissolution of Czechoslovakia , and has been amended in , , , , , , and Visa required prior to arrival. Since 1 January , multiple citizenship under Czech law is allowed. 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:. From Wikipedia, the free encyclopedia.