What Is a Prenup — and Who Actually Needs One?

A prenuptial agreement is a contract signed before marriage that defines how property and spousal support will be handled if the marriage ends by divorce or death. It can designate separate property, protect a business, address debt, and set or waive support — it cannot decide child custody or child support, which courts always retain. Far from being only for the wealthy, prenups do their best work in four situations: one or both spouses own a business, either has children from a prior relationship, there's a meaningful asset or debt imbalance, or a significant inheritance is expected.

What a Prenup Actually Protects

Most states treat property acquired during marriage as marital and property brought in as separate — but the line blurs in practice as accounts mix, businesses grow, and separate assets appreciate through marital effort. A prenup replaces those fact-intensive fights with clear definitions, which is why business owners sign them: the alternative can be a divorce-court valuation of the company and a buyout of a spouse's interest at the worst possible time.

What Makes Prenups Enforceable — and What Voids Them

Courts enforce agreements that are voluntary, based on full financial disclosure, and not unconscionable, with each side having had the opportunity for independent counsel. The classic failures: hiding assets during disclosure, presenting the document days before the wedding, and terms so one-sided a court won't stomach them. A prenup done right is boring paperwork months before the wedding; a prenup done wrong is expensive litigation later.

The Conversation Is the Real Product

Couples who negotiate a prenup complete full financial disclosure and align on money before marrying — which financial planners will tell you is rarer and more valuable than the document itself. Postnuptial agreements exist for couples who marry first, though they receive closer judicial scrutiny in many states.