Fifth District Rules Plain Language Govern Interpretation of Ante-Nuptial Agreement What is a Prenuptial Agreement? A Premarital or prenuptial or antenuptial agreement means an agreement between prospective spouses made in contemplation of marriage and to be effective upon marriage. The agreement typically speaks to issues relating to property and can involve virtually any interest or rights in any present or future real or personal property rights. Prenuptial agreements can also allocate rights and risks to the parties’ income and earnings, both active and passive.