What Should Be in a Prenup

A prenuptial agreement is only as strong as what it contains. Too vague and a court will not know how to apply it. Too one-sided and a judge may throw the whole thing out. The difference between a prenup that protects you and one that falls apart in court comes down to what you put in it — and what you leave out.

Many couples know they want a prenup but have no idea what it should say. A well-drafted prenuptial agreement addresses dozens of financial questions that affect both parties — from who pays which debts to what happens to a retirement account built during the marriage.

This guide covers what a prenup can include, what it cannot include, the essential clauses every agreement needs, and the mistakes that cause courts to throw them out.

What a Prenup Can Cover

A prenuptial agreement can address nearly any financial matter between two spouses. Courts enforce prenups that deal with property, debt, income, and support obligations. Here are the core provisions to consider.

Property classification. One of the most important functions of a prenup is defining what counts as separate property and what counts as marital property. Pre-marriage assets, future inheritances, and gifts can all be designated as separate property. Without a prenup, commingling these assets during marriage can blur the lines and expose them to division in divorce.

Property division. A prenup can specify how assets will be divided if the marriage ends. This overrides your state’s default rules — whether that is community property or equitable distribution. You can set percentages, allocate specific assets to each spouse, or create formulas tied to the length of the marriage.

Debt protection. A prenup can establish that each spouse is responsible for their own pre-marriage debts — student loans, credit card balances, car loans, or business liabilities. It can also address debts incurred during the marriage.

Spousal support (alimony). Many prenups waive, limit, or define the terms of spousal support. You can set a monthly amount, cap the duration, or tie alimony to the length of the marriage. Some states will not enforce a complete waiver if it would leave one spouse destitute.

Business interests. If one or both spouses own a business, the prenup can protect that interest from division. It can define whether appreciation during the marriage is separate or marital property, establish a valuation method, and set buyout terms.

Retirement accounts. 401(k)s, pensions, and IRAs accumulated during a marriage are typically marital property. A prenup can specify whether contributions made during the marriage are subject to division or remain with the account holder.

Real estate. A prenup can address what happens to a home bought before marriage, purchased during marriage, or inherited by one spouse — who keeps it, how equity is split, and whether refinancing is required.

Estate planning. A prenup can coordinate with wills and trusts to ensure assets pass according to each spouse’s wishes. This is especially important in second marriages. A spouse can waive their elective share — the legal right to claim a portion of the other’s estate — as part of the prenup.

What a Prenup Cannot Cover

Courts will refuse to enforce prenuptial provisions that deal with non-financial matters, violate public policy, or attempt to override a judge’s authority.

Child custody. A prenup cannot predetermine who gets custody of children. Courts decide custody based on the best interests of the child at the time of divorce — not based on an agreement signed years earlier, potentially before the child was born.

Child support. Child support cannot be waived, reduced, or predetermined in a prenup. It is the child’s right, not the parent’s. Courts calculate it using statutory guidelines based on current income and needs.

Illegal provisions. A prenup cannot require either party to do something unlawful or include terms that violate public policy — for example, a clause that creates financial incentives to divorce.

Personal lifestyle clauses. Weight requirements, chore divisions, rules about in-laws, and intimacy provisions are not enforceable. Courts do not regulate personal behavior through contracts. Including these clauses can undermine the credibility of the entire agreement.

Unconscionable terms. A prenup that leaves one spouse with nothing while the other retains everything will likely be struck down. Courts evaluate whether the terms were fundamentally unfair when signed and whether enforcement would be unconscionable at the time of divorce.

Essential Clauses for Every Prenup

Regardless of your financial situation, certain clauses should appear in every prenuptial agreement. These provisions form the backbone of an enforceable prenup.

Full financial disclosure. Both parties must attach a complete list of all assets, debts, income, and financial obligations. This is not optional. Incomplete disclosure is one of the top reasons courts invalidate prenups.

Definitions section. The prenup should clearly define key terms — what counts as marital property, what counts as separate property, and how income is classified. Ambiguity leads to disputes.

Property division terms. Spell out how assets will be divided if the marriage ends. Use specific language, percentages, or formulas — not vague statements like “fair and equitable.”

Debt allocation. Identify each spouse’s existing debts and state who is responsible for debts incurred during the marriage.

Spousal support terms. Either define the terms of alimony — amount, duration, and conditions — or include an explicit waiver. Silence on spousal support leaves the issue to the court.

Sunset clause. A sunset clause causes the prenup to expire after a specified number of years — commonly 10, 15, or 20 years. This is optional but increasingly common.

Amendment procedure. Include a process for modifying the prenup after marriage — typically a written amendment signed by both parties, sometimes called a postnuptial agreement.

Severability clause. This states that if a court finds one provision invalid, the rest of the agreement survives. Without it, a single bad provision could take down the entire prenup.

Governing law. Specify which state’s law applies. This is critical for couples who may relocate.

Voluntary execution. Both parties confirm they signed voluntarily, without coercion, and that each had the opportunity to consult independent counsel.

Clauses to Consider Based on Your Situation

Beyond the essentials, the right prenup clauses depend on your specific circumstances.

Business owners. Specify the valuation method (fair market value, book value, or a formula), set buyout terms, and clarify whether appreciation during the marriage is separate or marital property. Without these provisions, a divorce could force a sale or give your spouse a claim to a portion of the business.

High-income earners. Define how income earned during the marriage is classified. Address bonuses, stock options, restricted stock units, and deferred compensation. These are frequently disputed in divorce because they may be earned during the marriage but received afterward.

Inherited wealth. If you expect a significant inheritance or hold family assets in trust, the prenup should explicitly protect those assets as separate property — including any income or growth they generate during the marriage.

Second marriages. Couples entering a second marriage often need provisions that protect children from a prior relationship. A prenup can ensure that specific assets pass to those children rather than to the new spouse.

Entrepreneurs. If you are building a startup or developing intellectual property, address how those interests will be valued and divided. Startup equity, patents, and future business income need clear prenup language.

Couples who may relocate. Include a choice of law clause specifying which state’s rules govern the prenup. Property division rules vary significantly between community property and equitable distribution states, and a move can change which rules apply.

Mistakes That Invalidate Prenups

Even well-intentioned prenups can be thrown out if the process is flawed. These are the most common mistakes.

No independent counsel. Each party should have their own attorney. When one spouse drafts the prenup and the other signs without legal advice, courts are far more likely to find it unenforceable.

Signing under duress or too close to the wedding. A prenup presented days before the ceremony — with the implied threat of calling off the wedding — is vulnerable to challenge. Sign at least 30 days before the wedding. Many attorneys recommend 3 to 6 months.

Incomplete financial disclosure. If either party hides assets, undervalues property, or fails to disclose debts, the entire prenup can be invalidated.

Unconscionable terms. An agreement that is grossly unfair — leaving one spouse with nothing while the other keeps millions — will not survive court scrutiny.

Improper execution. Some states require prenups to be notarized or witnessed. Failing to meet your state’s requirements renders the agreement unenforceable regardless of its content.

Frequently Asked Questions

Can I include an infidelity clause in my prenup?

Some states allow infidelity clauses that adjust property division or spousal support if one spouse commits adultery. However, enforceability varies widely. In no-fault divorce states, courts may disregard them entirely. In states that recognize fault-based grounds, an infidelity clause is more likely to hold up. Ask your attorney whether this clause is enforceable in your state.

Should a prenup include a sunset clause?

A sunset clause is optional but worth considering. It causes the prenup to expire after a set number of years — often 10 to 20 years. A prenup designed at the start of a marriage may not reflect the couple’s reality decades later. Without one, the prenup stays in effect until amended, revoked, or the marriage ends.

Can a prenup waive alimony?

In most states, yes — but with limits. Courts in some states will not enforce a complete waiver if it would leave one spouse unable to support themselves. A partial waiver or formula-based approach (for example, $2,000 per month for every 5 years of marriage) is more likely to be upheld. See our guide on how alimony works for more detail.

Does each person need their own attorney?

Technically, most states do not require both parties to have independent counsel. Practically, it is one of the most important steps you can take to ensure enforceability. A prenup signed without independent legal advice is far easier to challenge. Courts often view the absence of separate attorneys as evidence that the agreement was not truly voluntary.

Can we modify a prenup after marriage?

Yes. A prenup can be modified through a written amendment signed by both spouses — sometimes called a postnuptial agreement. The same enforceability requirements apply: full disclosure, voluntary execution, and fair terms.

What to Do Next

Ready to draft a prenup or review one your partner has proposed? Here is how to move forward:

1. Make a list of your assets, debts, and priorities. Know what you own, what you owe, and what matters most to you before meeting with an attorney.
2. Discuss the key terms with your partner. Agree on the big-picture issues before involving attorneys. This saves time and legal fees.
3. Hire your own family law attorney. Each party needs independent counsel. Do not share an attorney.
4. Allow enough time. Start 3 to 6 months before the wedding. Rushing undermines both the agreement’s quality and its enforceability.
5. Schedule a consultation. A family law attorney can explain your state’s specific rules and help you build a prenup that protects both parties. Talk to an attorney today.