A mixed marriage is where one party is a Catholic and the other party is not a Catholic, whether baptised or not. A Catholic, even when entering a mixed marriage must be married before a Catholic priest.

Permission can be given for a Catholic to marry one who is not Catholic provided that the Catholic promises to safeguard his/her own Catholic faith and to do all in his/her power to have the children of their marriage baptised and raised as Catholic.

The partner who is not a Catholic, though not required to make a promise must be properly informed before the wedding of the obligations and expectations the Church has of their Catholic spouse.