A prenuptial agreement can cover property, debts, spousal support, business interests, retirement accounts, tax liability, and inheritance rights. What to include in a prenuptial agreement comes down to the financial decisions you want to lock in now instead of leaving to a judge or to default state law later. What you cannot include: anything about child custody or child support, and anything a court would read as encouraging divorce or governing non-financial conduct.
The clauses below are the ones that do real work. Each one has rules that make it stick, and traps that quietly undo it.
What Has to Be True for Any Clause to Hold Up
Before the specific terms matter, the agreement itself has to be enforceable. Oral prenups are not enforceable anywhere. The agreement must be in writing and signed by both parties, and courts look at four things when deciding whether to honor it:
- Voluntary consent. Both parties must sign willingly. Presenting an agreement days before the wedding, after invitations are sent and deposits paid, invites a duress claim. Sign well in advance.
- Independent legal counsel. Not every state requires each party to have their own lawyer, but courts view a prenup with far more skepticism when one side had no representation. Under the updated model uniform act, a party who lacked access to independent counsel can challenge enforceability.
- Full financial disclosure. Each party must provide a reasonably accurate picture of assets, debts, and income before signing. Hidden accounts or understated values can invalidate the entire agreement.
- Substantive fairness. Terms that were unconscionable when signed, or that create extreme hardship by the time of enforcement, can be struck down.
The updated model act lets a court override a spousal support waiver if enforcing it would leave one spouse eligible for public assistance at the time of divorce.1Uniform Law Commission. Uniform Premarital and Marital Agreements Act That safety valve exists even in states that generally favor enforcing prenups as written.
Property: Separate, Marital, and the Commingling Problem
The most common reason to sign a prenup is to control what happens to property. Without one, state law dictates the split.
Separate property typically includes anything owned before the marriage, plus gifts and inheritances received individually during it. Marital property covers assets acquired by either spouse while married. Your agreement can confirm these default categories or override them. You might agree that a rental property owned before the wedding stays with the original owner no matter what, including any increase in value.
Writing it down is only half the job. During the marriage, your behavior can undo what the agreement says. Commingling happens when you mix separate property with marital property so thoroughly that a court can no longer tell what belongs to whom. The classic example: depositing an inheritance into a joint checking account used for groceries, vacations, and mortgage payments. Once those funds blend, proving which dollars were yours becomes difficult or impossible.
A well-drafted prenup should address this directly. It can specify that depositing separate funds into a joint account for convenience doesn’t convert them to marital property, as long as you maintain records showing the source. It can also address what happens when marital funds improve separate property, like when both spouses pay the mortgage on a home one of them owned before the wedding. Without clear language on these scenarios, the agreement’s property classifications erode through everyday financial decisions.
Spousal Support
You can waive support altogether, cap it at a specific amount, limit its duration, or tie it to factors like the length of the marriage or each spouse’s income at divorce.
Courts scrutinize these provisions more heavily than almost anything else in a prenup. A complete waiver that looked reasonable when both spouses earned similar incomes may become unenforceable ten years later if one spouse left the workforce to raise children. Judges generally won’t uphold a waiver that would leave one spouse in severe financial hardship, regardless of what the agreement says. Specific, graduated provisions survive judicial review far more reliably than blanket waivers. Building in adjustments tied to the length of the marriage or changes in earning capacity makes enforcement more predictable.
Debt Allocation
Debts deserve the same attention as assets. A prenup can assign responsibility for pre-marital debts like student loans or credit card balances, keeping one spouse from inheriting the other’s financial baggage. It can also spell out how debts incurred during the marriage will be divided, whether that’s a mortgage, car loan, or medical bills.
Without a prenup, divorce courts in many states can assign marital debt to either spouse regardless of whose name is on the account. A clear allocation clause protects both parties. For these provisions to hold up, both spouses need to disclose all existing debts during drafting. Hidden debts discovered later can undermine the entire agreement.
Tax Liability
If you file jointly during the marriage, the agreement can specify how you’ll split any tax liability or divide refunds. It can also clarify that filing a joint return doesn’t convert separate assets into marital property. For separate property, the agreement can assign tax reporting and payment responsibility to the spouse who owns the asset. In community property states, a prenup can even allow spouses to opt out of community property treatment for income tax purposes, treating their income as if they lived in a non-community-property state.2IRS. Internal Revenue Manual Part 25-015-005
Business Interests
If either spouse owns a business, a professional practice, or valuable intellectual property, the prenup should address it specifically. Without a clear provision, a divorce court might treat part or all of the business as marital property, potentially forcing a sale or buyout at the worst possible time.
The tricky part is appreciation. A business you started before the marriage is your separate property, but its growth during the marriage might not be. Courts distinguish between passive appreciation and active appreciation. If the business grew because the broader market lifted all boats, that increase generally stays separate. If it grew because you or your spouse put in long hours building it, that growth may be treated as marital property. A prenup can address this head-on by classifying all appreciation as separate, setting a formula for valuing any marital share, or establishing a buyout mechanism.
The agreement can also set the method for valuing the business, whether that’s book value, a multiple of earnings, or an independent appraisal. Agreeing on the method in advance avoids one of the most contentious and costly aspects of divorcing business owners.
Retirement Accounts and the Federal Law Trap
Retirement accounts are often the largest asset a couple owns, and they come with a legal trap. Federal law governing employer-sponsored retirement plans like 401(k)s and pensions requires specific procedures for waiving survivor benefits, and a prenup signed before the wedding does not satisfy those requirements.
Under federal law, the spouse of a retirement plan participant has an automatic right to survivor benefits. Waiving that right requires written consent from someone who is already a spouse, witnessed by a plan representative or notary public. The waiver must designate an alternate beneficiary or payment form, and it must be submitted to the plan during an applicable election period.3Office of the Law Revision Counsel. United States Code Title 29 – 1055 Because you aren’t married yet when you sign a prenup, any waiver of these benefits inside the prenuptial agreement is not binding on the plan.
The fix is straightforward but easy to forget. After the wedding, sign a postnuptial agreement or a standalone spousal consent form that confirms the waiver under the proper federal procedures. Skip this step and the retirement provisions are effectively decorative. The prenup should explicitly flag the need for the post-marriage follow-up document.
IRAs follow different rules since they aren’t governed by the same federal statute, so a prenup can address IRA division more directly. For any employer-sponsored plan, the post-wedding waiver step is essential.
Inheritance and Estate Rights
A prenup can reshape what happens to your assets when you die, not just when you divorce. Most states give a surviving spouse the right to claim a share of the deceased spouse’s estate regardless of what the will says. A prenup can waive that right, which matters enormously if you want to leave the bulk of your estate to children from a prior marriage or to other beneficiaries.
Spouses can use a prenup to agree that each party’s separate property passes according to their own estate plan, free of any spousal claim. The waiver of elective share rights in a prenup overrides the state laws designed to protect a surviving spouse, making it one of the most powerful estate planning tools available to couples entering second or third marriages.4Nolo. Prenuptial Agreements and Inheritance Rights – Section: Prenuptial Agreements Override State Property Laws
A prenup is not a substitute for a will or trust. It works alongside those documents, and the three need to be consistent. If your prenup waives your spouse’s inheritance rights but your will leaves everything to your spouse, the conflict creates exactly the kind of expensive legal dispute you were trying to avoid. Review your estate plan whenever you draft or update a prenup.
Optional Clauses That Add Durability
Sunset Clauses
A sunset clause sets an expiration date on the agreement. After a specified number of years of marriage, the prenup either terminates entirely or specific provisions fall away. Ten to twenty years is a common range. Couples use sunset clauses when they want protections for the early years of marriage but believe that a long-lasting union should eventually be governed by standard state law. If you include one, make the language precise about which provisions expire and which survive. Vague drafting can accidentally void protections you intended to keep.
Dispute Resolution
You can require that disagreements about the prenup go through mediation or arbitration rather than straight to court. Mediation is less adversarial and typically cheaper than litigation. Arbitration produces a binding decision without a public court record. Either option can reduce the cost and emotional toll of enforcing the agreement if the marriage ends.
Confidentiality
A confidentiality clause can prevent either spouse from disclosing the terms of the prenup or sensitive financial details revealed during the disclosure process. These are common when one or both spouses are public figures or business owners.
What You Cannot Include
Certain provisions will not survive judicial review, and including them can undermine the credibility of the rest of the agreement.
Anything About Children
No prenup can predetermine child custody, visitation schedules, or child support amounts. Courts decide these issues based on the child’s best interests at the time of the proceeding, and they will not defer to an agreement the parents made years earlier under different circumstances. Any child-related provisions are unenforceable.
Terms That Encourage Divorce or Violate Public Policy
Clauses that create a financial incentive to end the marriage are suspect. A provision paying one spouse a large bonus for filing for divorce could be struck as encouraging marital dissolution. Terms that are grossly one-sided at signing, or that become unconscionable by the time of enforcement, can also be invalidated.
Infidelity and Lifestyle Clauses
Financial penalties for adultery come up often, but enforceability is genuinely uncertain. Some states have upheld them; others have rejected them as inconsistent with no-fault divorce principles. Building your financial plan around an infidelity clause is risky. If you include one, it needs clear definitions, proportionate consequences, and an understanding that a court may disregard it. A poorly drafted infidelity clause can put the rest of the agreement at risk if a judge finds it offensive to public policy.
Non-financial lifestyle provisions, like who does the dishes or how often you visit in-laws, are not enforceable. Courts treat prenups as financial contracts and have no interest in adjudicating household chores.