An antenuptial agreement, more commonly known as a prenuptial agreement, is a contract entered into between prospective spouses before they get married. The reasons people enter in to these contracts are many, but generally the purpose is to protect their assets in case the marriage ends in divorce.
There is no express statutory authority in MO giving approval to these contracts, conversely, there are no statutes against them. That said, in MO prenups are examined very closely to make sure the signers made an informed decision. In Hosmer v. Hosmer, the MO Supreme Court observed that “the relation of a man to a woman he is about ot marry is a confidential one in an exacting and stringent sense…he carries the burden of showing that any antenuptial contract entered into under the glow and trust of that tender relationship was entered into fairly.” In other words, the Court wants to make sure love did not cloud your judgment.
So at the end of the day, a prenup is a valid, binding contract, and both parties can spell out almost anything they want in the contract. Although the great majority of prenups in MO follow a standard form and generally adhere to normal principles, the contract is not limited and in some cases couples have negotiated penalties for infidelity, the number of days between the time they are served with divorce papers and the time they must vacate the marital home and who gets the pets.
To overturn a prenup, the spouse seeking to overturn will have to show that they did not understand what they were signing when they entered in to the contract, but it’s not enough to just allege that, the petitioning party must then prove that they were unclear on what they were doing. For example, if there was little or no time to consider the contract or take it to another attorney for review or coercive behavior was used to make you sign, then those are good reasons why you the contract should be overturned.
If you are successful in getting the prenup voided, then the statutory rules on Dissolution apply.