Even if you try to codify custody and support in your post-nup, it won’t be enforceable unless a court agrees with you on every point. Post-nuptial agreements can be a murky area of the law ...

Are Postnuptial Agreements Enforceable? Postnuptial agreements are not yet fully recognized in all 50 states, so you will need to review the laws of your state before entering into an agreement.