The legal requirement for sacramental marriage is that at least one of the parties must be Catholic and both must live in a "free state." This means that the Catholic spouse has never entered into a church marriage and the non-Catholic spouse has not previously entered into a civil or church marriage. This must be proven by the Catholic spouse by means of a baptismal certificate that is not older than three months from the date of the vow and can be obtained from the baptismal parish. The non-Catholic spouse must make an official declaration that he or she is free.
The moral condition of sacramental marriage is that they want to live their married life in a Christian way and lead their unborn children to the Christian life.
More information about the sacrament can be found in Hungarian on the website of the Archdiocese of Esztergom-Budapest.