Prenup clauses fall into three groups: the ones nearly every state will enforce, the ones that depend on where you live and how the agreement was drafted, and the ones no court will touch no matter what both of you signed. Getting the mix right is what separates a prenuptial agreement that actually protects you from one that collapses the moment it is challenged.
Dividing Property and Assets
The core clause of most prenups draws a line between separate and marital property. What you owned before the wedding stays yours. What the two of you acquire during the marriage gets divided by whatever formula you agree on. Skip this clause and state law decides the split, and many states treat nearly everything acquired during marriage as jointly owned regardless of whose name is on the title.
A workable asset clause goes beyond categories. It says what happens when separate property gains value. If you own a house worth $400,000 at the wedding and it is worth $600,000 at divorce, the prenup should answer directly whether your spouse has any claim to that $200,000 gain. The same question applies to investment accounts, real estate, and anything else likely to appreciate.
Both parties also have to attach a complete financial schedule listing every significant asset, debt, and income source. Full disclosure is a requirement in most states and courts take it seriously. If a spouse can later prove the other hid a brokerage account or understated a property’s value, a judge can throw out the whole agreement. The disclosure does not have to be perfect to the dollar, but it has to give an honest picture.
Protecting a Business
Business owners usually have the most to lose in a divorce, and a prenup is the most reliable way to keep a company off the negotiating table. The central clause defines the business and the income it generates as separate property, so a divorce does not force a sale or hand voting rights to a spouse who did not build the entity.
Appreciation is where business clauses get tested. A company that grows during the marriage raises the question of whether that growth counts as a marital asset. If you started a business worth $1 million before the wedding and it is worth $5 million ten years later, the default rule in many states would let your spouse claim a share of that increase. A well-drafted prenup either assigns all appreciation to the owner or sets a formula for compensating the other spouse without giving them an ownership stake.
Confidentiality and non-compete provisions deserve a look too. A confidentiality clause stops a spouse from sharing proprietary information learned during the marriage. A non-compete keeps a spouse from launching a competing venture using knowledge gained through the relationship. These matter most when the spouse has been actively involved in the business.
Allocating Debt
A debt clause keeps your partner’s financial baggage off your balance sheet. The standard approach assigns premarital debt to whoever incurred it, so student loans, car payments, and credit card balances from before the wedding stay with that spouse.
Debt taken on during the marriage needs its own treatment. Joint obligations like a mortgage usually get split under the prenup’s terms, while debt one spouse incurs for individual purposes stays with that spouse. If your spouse borrows $50,000 to fund a side venture that fails, a well-written debt clause keeps creditors away from your assets.
Tax debt deserves a separate line. Couples who file jointly are both liable for the full bill, and the IRS does not care what your prenup says. What a prenup can do is include an indemnification clause requiring the spouse who caused the deficiency to reimburse the other. The IRS can still collect from either of you, but between the two of you, the one responsible for the underreporting owes the other.
Spousal Support and Sunset Provisions
Alimony clauses range from a complete waiver to a detailed payment schedule. Full waivers are enforceable in many states, but courts look at them closely. Under the framework roughly half the states have adopted based on the Uniform Premarital Agreement Act, a judge can override an alimony waiver if enforcing it would leave one spouse eligible for public assistance.
Many couples skip the blanket waiver and set a predetermined support amount instead. The agreement might set a fixed monthly sum for a set number of years, or a lump sum at separation. Some tie the number to how long the marriage lasted, with support growing for each additional year together.
Sunset clauses are increasingly common. A sunset provision puts an expiration date on part of the prenup, or on all of it. A prenup might waive alimony for the first ten years, then let state law apply to any divorce filed afterward. Once a sunset kicks in, the affected provisions disappear and the court applies default state rules as if the prenup never addressed the issue.
Waiving Inheritance Rights
When one spouse dies, state probate law gives the survivor a right to claim a percentage of the estate even if the will leaves everything to someone else. This elective share usually runs from about one-third to one-half of the estate, depending on the state. A prenup clause waiving the elective share ensures that specific assets pass to children from a prior marriage, other relatives, or anyone else the deceased named.
These clauses work alongside a will and any trusts. The prenup handles the waiver; the will and trusts direct where the assets actually go. Without the waiver, a surviving spouse can override the will by electing their statutory share and derail an estate plan.
The trigger here is death, not divorce. A prenup can carry separate provisions for each scenario, with different rules applying to each. Anyone with children from a prior relationship should treat the death clause as seriously as the divorce clause.
The Retirement Account Limit
This is where prenups hit a wall. Federal law governing employer-sponsored retirement plans like 401(k)s and pensions overrides any prenuptial agreement. Under ERISA, a waiver of plan benefits requires spousal consent, and that consent can only come from someone who is already a spouse. Because a prenup is signed before the wedding, the parties are not spouses yet, so any waiver of qualified plan benefits in the prenup itself is legally meaningless.1Office of the Law Revision Counsel. United States Code Title 29 Section 1055
You can still address retirement assets, just not directly through the prenup alone. A prenup can create a contractual obligation for the spouse to sign a plan-level waiver after the wedding, using the plan’s own procedures. If the spouse refuses later, the prenup gives you a breach-of-contract claim. The plan itself will not honor the prenup. IRAs are different because ERISA does not govern them, so a prenup can address IRA assets more directly, subject to state law.
Any prenup that touches a 401(k) or pension needs a follow-up step after the wedding: a clause requiring both spouses to execute the appropriate plan-level waivers within a set time after the ceremony.
Tax Basis and Filing
Property transfers between spouses during marriage or as part of a divorce carry no immediate tax bill. Federal law treats them as gifts with no recognized gain or loss, and the recipient takes over the original owner’s tax basis.2Office of the Law Revision Counsel. United States Code Title 26 Section 1041 – Transfers of Property Between Spouses or Incident to Divorce
Carryover basis matters more than most people realize. If your spouse transfers a rental property they bought for $200,000 that is now worth $500,000, you inherit the $200,000 basis. When you sell, you owe taxes on $300,000 in gains. A prenup that divides assets purely by current market value without accounting for embedded tax liability can leave one spouse with a much worse deal than it looks on paper. Good drafting either adjusts the division to account for basis or includes an explicit clause on how unrealized gains are handled.
The tax-free transfer rule covers transfers within one year after the marriage ends, or transfers related to the end of the marriage. Transfers to a nonresident alien spouse do not qualify.2Office of the Law Revision Counsel. United States Code Title 26 Section 1041 – Transfers of Property Between Spouses or Incident to Divorce
Prenups can also address how the couple files during the marriage. Joint filing usually produces a lower combined bill, but both spouses become jointly liable for the whole amount. A filing clause can commit the couple to joint returns while an indemnification provision allocates responsibility if one spouse’s reporting triggers an audit or deficiency.
Infidelity Clauses
Infidelity clauses impose a financial penalty on a spouse who cheats, and they are among the most requested and least reliable provisions a prenup can contain. Enforceability varies dramatically by state with no national consensus. Some courts have upheld them, including a Florida case where proven adultery triggered alimony that had been waived in the prenup, and a Maryland case enforcing a $7 million penalty. Other states with strong no-fault divorce policies, including California and Iowa, have refused to enforce them on the ground that marital misconduct should not drive financial outcomes.
An infidelity clause may still carry weight in negotiations even if it would not survive a court challenge, because the risk of enforcement creates pressure to settle. But if the plan is to win millions in court because a spouse was unfaithful, that plan rests on a provision most family law practitioners view as unreliable.
Clauses Courts Will Not Enforce
Some provisions are void no matter what both parties agreed to. The most absolute involves children. No prenup can set custody, dictate visitation, or cap child support. Courts decide child-related matters based on what is best for the child at the time of the proceedings, and parents cannot contract those rights away in advance.
Provisions that incentivize divorce are also unenforceable. If a clause promises an outsized financial reward for ending the marriage, courts treat it as encouraging divorce and refuse to apply it. Agreements with large per-year payouts have failed on this ground because the accumulating payout gives one spouse an obvious financial motive to file.
Lifestyle clauses sit in a gray area that leans heavily toward unenforceable. Terms dictating a spouse’s weight, appearance, housekeeping, or frequency of intimacy strike most courts as unconscionable. They show up occasionally in celebrity prenups, but they rarely survive judicial review. A court that finds one clause unconscionable may use that finding to scrutinize the rest of the agreement more aggressively.
The catch-all limit is unconscionability itself. Courts evaluate this on two tracks: whether the process of creating the agreement was fair, and whether the actual terms are fair. An agreement signed under pressure with no time to review has procedural problems. An agreement that leaves one spouse with nothing after a long marriage has substantive problems. Either kind can sink the whole document.
What Makes the Agreement Hold Up
Good clauses still fail if the process of creating the prenup was flawed. Courts across the country weigh several factors, and failing on any one can unravel everything.
Voluntariness and Timing
Both parties must sign voluntarily, without coercion. The strongest evidence of voluntariness is time. Presenting a prenup months before the wedding gives both sides room to negotiate, consult attorneys, and make changes. Dropping it on your fiancé the week before the ceremony practically invites a court to throw it out. Family law attorneys generally recommend finalizing the agreement one to three months before the wedding date.
Full Financial Disclosure
Hiding assets is the fastest way to void a prenup. Both parties should exchange detailed financial statements covering income, assets, debts, and business interests, and the statements should be attached to the agreement as exhibits. If a spouse can later show they were never told about a significant asset, the court has grounds to set the agreement aside.
Independent Legal Counsel
Not every state requires each party to have their own lawyer, but the absence of independent counsel is one of the most common grounds used to challenge a prenup. A spouse who signed without legal advice can argue they did not understand the terms or the rights they gave up. Separate attorneys for each party largely eliminate that argument.
Written and Properly Executed
Every prenup has to be in writing and signed by both parties. Oral prenuptial agreements are unenforceable everywhere. Notarization and witnesses strengthen the document, especially for provisions affecting real estate or inheritance, because they give the court strong evidence that both parties knew what they were signing.
Changing a Prenup After the Wedding
A prenup signed at 28 may not fit at 45. Under the framework most states follow, a prenup can be amended or revoked after marriage, but only through a new written agreement signed by both spouses. A verbal agreement to ignore the prenup will not hold up.
A post-marriage amendment should identify the original agreement, specify which provisions are changing, and include updated financial disclosures. The same enforceability rules apply: both spouses sign voluntarily, and the revised terms cannot be unconscionable or violate public policy. If only one spouse wants changes, the other has no obligation to agree, and the original stays in effect.