A prenuptial agreement’s clauses fall into a predictable set: who keeps what they brought into the marriage, how jointly acquired property gets divided, who is responsible for which debts, and whether spousal support will be paid, waived, or capped. Those are the provisions that do the work. Everything else in a prenuptial agreement, from disclosure schedules to severability language, exists to make those core clauses enforceable when a court eventually reads them.
Property Division Clauses
The most important job of a prenup is drawing a line between separate property and marital property. Separate property is what one person owned before the wedding: a house, an investment account, a family business. A clause can state that this property, including any appreciation in its value, stays with the original owner. The same protection can extend to gifts and inheritances received during the marriage, as long as those assets aren’t mixed with joint funds.
Marital property covers what the couple acquires together through shared income or joint effort. Rather than leaving division to a court’s equitable-distribution analysis, prenup clauses often set a fixed percentage for splitting joint assets. The agreement can also address specific items. A primary-residence clause, for example, can spell out whether one spouse has the right to stay in the home for a set period after separation and how a buyout would be calculated.
Each spouse typically retains the right to sell, transfer, or manage their separate property without the other’s consent. That autonomy is one of the main reasons people sign a prenup, but it only holds up if the separate property actually stays separate.
The Commingling Problem
This is where most property clauses quietly fail. Commingling happens when separate property gets mixed with marital property, and it can erase the protection the clause was designed to create. Deposit an inheritance into a joint checking account, and a court may treat the entire account as marital property. Use joint income to pay the mortgage on a house owned before the marriage, and that house starts looking like a shared asset.
The legal term for this shift is transmutation, and it often hinges on intent: adding a spouse to a deed, using an inheritance to pay down a joint mortgage, or losing track of which dollars came from where. The burden of proof falls on the person claiming the asset is still separate, which means a clear paper trail matters.
A good prenup anticipates this risk. It should define what happens if separate funds are accidentally deposited into a joint account, and it should require each spouse to maintain individual accounts for separate property. The contract language helps, but day-to-day financial discipline is what actually preserves the protection.
Debt Clauses
Debts get the same level of detail as assets. A prenup should assign responsibility for pre-marital debts, such as student loans or credit card balances, to the person who incurred them. This keeps creditors from reaching the other spouse’s assets. Future debts taken on during the marriage, including business loans or car financing, are typically addressed through indemnification language: if one spouse defaults on their own debt, the other must be reimbursed for any resulting losses.
The practical side matters as much as the drafting. Keeping debt in the name of the person who incurred it, avoiding joint credit cards, and maintaining separate accounts for separate obligations reinforces the legal protections the prenup creates. A well-written clause means nothing if the couple’s actual financial behavior contradicts it.
Spousal Support Clauses
Every state allows a prenup to address spousal support, though the rules on how far you can go vary. Some agreements waive alimony entirely, which works best when both people have independent careers and comparable earning power. Others set a formula, such as a fixed monthly payment for each year the marriage lasted, or specify that support only kicks in after a minimum number of years.
A handful of states will override an alimony waiver if enforcing it would leave one spouse dependent on public assistance. Courts in those states reason that taxpayers shouldn’t subsidize a private agreement that leaves someone destitute. If you are waiving support, your attorney should flag whether your state has that kind of safety valve.
Sunset Clauses
Sunset clauses set an expiration date on the entire agreement or on specific provisions. The most common use is around alimony: a waiver of spousal support might expire after ten or fifteen years of marriage, reflecting the idea that a long marriage creates different economic expectations than a short one. Sunset clauses can also convert what started as separate property into marital property after a set milestone.
Drafting these clauses requires precision. In one widely discussed case, a couple’s prenup expired on their seventh wedding anniversary. The husband filed for divorce four months before the anniversary, but the divorce wasn’t finalized in time. The court sided with the wife and voided the agreement, because the expiration was tied to the anniversary date rather than the filing date. If you include a sunset clause, define the trigger event exactly.
Financial Disclosure: What Makes the Clauses Enforceable
No prenup survives a legal challenge without full financial disclosure from both sides. Under the Uniform Premarital Agreement Act, which roughly half the states have adopted in some form, an agreement is unenforceable if one party was not given a fair and reasonable picture of the other’s finances before signing.1Uniform Law Commission. Premarital and Marital Agreements Act States that haven’t adopted the UPAA apply similar principles through their own contract and family law rules. The core idea is the same everywhere: you can’t agree to give up rights you didn’t know you had.
In practice, disclosure means gathering several years of federal tax returns, current appraisals on real estate, and detailed statements for every investment account, retirement plan, and bank account. These records are typically attached as numbered schedules at the end of the agreement, creating a snapshot of each person’s wealth on the signing date. List specific account numbers and current fair market values. Vague or incomplete disclosures invite exactly the kind of challenge the prenup is supposed to prevent.
If either party owns a private business, a simple account statement is not enough. Businesses need a formal valuation by a qualified professional, performed independently rather than relying on the owner’s estimate. The prenup should identify the business’s value at the time of marriage as separate property and include a formula for how future growth will be treated. For fast-growing companies, periodic revaluation clauses tied to milestones like major funding rounds help keep the agreement realistic over time.
Tax Consequences Built Into the Clauses
Prenup clauses create tax consequences that catch people off guard, especially around alimony and property transfers.
For any divorce agreement executed after 2018, alimony payments are not deductible by the person paying and are not counted as income for the person receiving them.2Internal Revenue Service. Topic No. 452, Alimony and Separate Maintenance This is a permanent change under the Tax Cuts and Jobs Act and applies to every new prenup. If your agreement includes a spousal support formula, both sides need to run the after-tax math rather than assuming the old deduction rules still apply.
Property transfers between spouses during marriage or as part of a divorce carry no income tax and no gift tax. Federal law treats these transfers as gifts for tax purposes, meaning the receiving spouse takes over the original owner’s cost basis rather than getting a stepped-up basis at the property’s current market value.3Office of the Law Revision Counsel. 26 USC 1041 – Transfers of Property Between Spouses or Incident to Divorce The unlimited marital deduction means gifts between spouses are not subject to gift tax.4Internal Revenue Service. Frequently Asked Questions on Gift Taxes The basis carryover matters, though. If you receive appreciated stock from your spouse and later sell it, you will owe capital gains tax on the full appreciation, not just the gain since you received it. A prenup that transfers a $500,000 asset with a $50,000 cost basis is also transferring a $450,000 built-in tax bill.
Clauses a Court Will Not Enforce
Some provisions are off-limits regardless of what both parties agreed to, and including them can jeopardize the rest of the document.
- Child custody and visitation. Every state prohibits prenuptial agreements from setting custody arrangements or defining visitation schedules. Courts determine custody based on the child’s best interests at the time of separation, not based on what two people agreed to before the child existed.
- Child support. No state allows a prenup to cap, waive, or define child support obligations. A child’s right to financial support from both parents cannot be bargained away by the parents.
- Lifestyle clauses. Provisions that impose financial penalties for infidelity, weight gain, or other personal behavior are a gamble. In no-fault divorce states, courts generally refuse to enforce them, because they require a judge to assign fault in a system designed to avoid exactly that. A few states have upheld infidelity penalties, but the outcome is unpredictable enough that most family law attorneys advise against including them.
Depending on the jurisdiction and how the agreement is drafted, a court might strike the offending clause and enforce the rest, or it might use the problematic provision as evidence that the entire agreement is unconscionable. A severability clause helps protect against the second outcome, but the safer approach is to leave these topics out entirely.
Grounds for Throwing Out a Prenup
Even a signed, notarized agreement can be set aside if the circumstances surrounding its creation were unfair. Courts evaluate challenges under two broad frameworks.
Procedural Problems
Procedural problems involve how the agreement was negotiated and signed. The most common are presenting the agreement for the first time days before the wedding, failing to provide adequate financial disclosure, and pressuring one party to sign without time to consult an attorney. Courts recognize that the practical difficulty of canceling a wedding creates real coercive pressure, even without explicit threats.1Uniform Law Commission. Premarital and Marital Agreements Act
The standard recommendation is to begin the process at least 60 to 90 days before the wedding. That window allows time for drafts, financial disclosure, negotiation, independent attorney review, and a signing date that doesn’t feel like an ultimatum. Courts look at the totality of the circumstances rather than any single factor, but tight timelines consistently raise red flags.
Substantive Problems
Substantive challenges target the terms themselves. An agreement is unconscionable when its provisions are so lopsided that they shock the conscience of the court. Examples include an extremely unequal property split that leaves one spouse with virtually nothing, a complete alimony waiver when one party gave up a career to raise children, or terms that violate public policy. The bar is high because adults are generally free to make bad deals, but it isn’t infinite.
Signing It So It Sticks
Most states don’t technically require both parties to have their own lawyer for a prenup to be valid. But skipping independent counsel is one of the fastest ways to make an agreement vulnerable. When only one attorney drafts the document, courts view the result with heightened skepticism, because the other party may not have fully understood what they were giving up. Lack of independent representation strengthens nearly every other challenge: it supports claims of unconscionability, makes duress arguments more credible, and undercuts the idea that the person gave informed consent. Each attorney should represent only one party and should never attempt to represent both.
Execution requirements vary more than most people expect. The Uniform Premarital Agreement Act itself does not require notarization, and many states follow that approach. Other states require notarization, particularly if the agreement involves real estate transfers. A few states require one or two witnesses. Because the rules depend entirely on where you live, this is one area where local counsel is non-negotiable. Regardless of your state’s minimum, notarize the signatures anyway. Notarization provides independent verification that both parties appeared voluntarily and showed valid identification. Each spouse should receive a signed original, and each attorney should retain a copy. The agreement becomes a binding contract once signed, but it only takes legal effect when the marriage ceremony occurs. If the wedding doesn’t happen, the prenup is just a draft.