Acquiring Austrian citizenship by descent

Children acquire citizenship at the time of their birth if their mother is an Austrian citizen. The same applies if the parents are married and only the father is an Austrian citizen.  

If the parents are not married and the father is an Austrian citizen, but the mother is a citizen of another state, the child acquires Austrian citizenship by descent if their Austrian father acknowledges paternity within eight weeks following the birth, or if his paternity has been legally established by a court. Paternity can also be acknowledged before the child is born. Where paternity is only acknowledged more than eight weeks after the birth, or where paternity is determined by a court, children can have Austrian citizenship conferred upon them under facilitated conditions.

If the child acquires another citizenship at birth in addition to Austrian citizenship – e.g. by descent from the other parent ("ius sanguinis") or by birth in a state (e.g. USA) where the territoriality principle ("ius soli") applies – then there is no loss of Austrian citizenship, but the child has two citizenships (dual citizenship). Under Austrian law, the child does not have to decide on one nationality when he or she reaches the age of majority; however, it may be that the other state requires a decision.

Legal basis

Section 7 of the Staatsbürgerschaftsgesetz