In contrast to the past, nowadays the law knows only a few marriage prohibitions—meaning the presence of certain circumstances under which the registrar may not marry. These are:
- Kinship:
Marriage may not be contracted between blood relatives in a straight line and between full or half siblings. However, marriage between cousins is not prohibited. If there is kinship, the marriage is null and void, and this nullity cannot be cured.
- Double marriage:
In Austria the principle of single marriage applies—a marriage with a second person at the same time is therefore not possible. A violation of the prohibition of double marriages also leads to incurable nullity.
- Adoption:
Adoption also precludes marriage, although the restrictions are less far-reaching than in the case of kinship. Thus, while the adopted child and its descendants and the adopter are prohibited from marrying while the adoption is in force, there is nothing to prevent marriage if the adoption is removed.
