What Is a Prenuptial Agreement?

A prenuptial agreement — commonly called a “prenup” — is a legally binding contract that two people sign before getting married. It specifies how assets, debts, and spousal support will be divided if the marriage ends in divorce or death. Once considered taboo, prenups have become mainstream: a 2022 Harris Poll found that 15% of married Americans have one, and 40% of unmarried adults say they would consider signing one.

How Does a Prenuptial Agreement Work?

Both parties disclose their financial positions — income, assets, debts, and expected inheritances — and then negotiate terms that will govern property division and support if the marriage ends. Each party should have independent legal counsel review the agreement before signing.

Once signed, the prenup sits dormant unless the couple divorces or one spouse dies. At that point, it overrides default state property-division laws and replaces them with the terms the couple agreed to.

What Can a Prenuptial Agreement Cover?

Prenups are highly customizable. Common provisions include:

• Separate property protection — Designating assets owned before marriage (homes, investments, family businesses) as separate property that will not be divided
• Debt allocation — Specifying that premarital debts (student loans, credit card balances) remain the responsibility of the spouse who incurred them
• Spousal support terms — Setting alimony amounts, duration, or waiving it entirely
• Business ownership — Protecting a family business or professional practice from division
• Inheritance protection — Ensuring inherited assets or expected inheritances stay with the receiving spouse
• Property division formula — Establishing a custom split (e.g., 60/40 instead of the state default) for marital assets
• Sunset clause — A provision that causes the prenup to expire after a certain number of years (often 10—20 years)

What Can a Prenuptial Agreement NOT Cover?

Courts will not enforce prenup provisions that address:

• Child custody or visitation — These decisions must be made based on the child’s best interests at the time of divorce, not predetermined by contract
• Child support — Support obligations belong to the child and cannot be waived or limited by the parents
• Illegal terms — Any provision that incentivizes divorce or requires illegal activity
• Personal lifestyle clauses — Weight requirements, household chores, or intimacy schedules are generally unenforceable (though some states allow limited lifestyle provisions)
• Unconscionable terms — Courts can void agreements that are so one-sided they “shock the conscience”

Requirements for Enforceability

A prenup must meet specific legal standards to hold up in court. Requirements vary by state, but most follow the Uniform Premarital Agreement Act (UPAA), adopted by 28 states, or its updated version (UPMAA).

Requirement	Details
Written and signed	Oral prenups are not enforceable in any state
Voluntary execution	Neither party can be coerced or pressured into signing
Full financial disclosure	Both parties must honestly reveal all assets, debts, and income
Independent legal counsel	While not required in every state, courts strongly favor agreements where both parties had their own attorney
Timing	The agreement should be signed well before the wedding — ideally 30+ days — to avoid claims of duress
Not unconscionable	The terms must be fair at the time of signing (and in some states, also at the time of enforcement)

The most common reason prenups get thrown out is inadequate financial disclosure. If one spouse hid a bank account or undervalued a business, the entire agreement may be voided.

When Should You Get a Prenuptial Agreement?

Prenups are especially valuable when:

• One or both spouses own significant assets before marriage
• One spouse has substantially more debt than the other
• Either spouse owns a business or professional practice
• There are children from a prior marriage whose inheritance needs protection
• One spouse expects a large inheritance
• There is a significant income disparity between the spouses
• Either spouse is entering a second or third marriage

Financial planners generally recommend discussing a prenup at least 3—6 months before the wedding to allow adequate time for negotiation and review.

How Much Does a Prenuptial Agreement Cost?

Prenup costs vary based on complexity and location:

Complexity	Typical Cost Range
Simple (few assets, straightforward terms)	$1,500—$3,000 per spouse
Moderate (business interests, multiple properties)	$3,000—$7,500 per spouse
Complex (high net worth, trusts, international assets)	$7,500—$25,000+ per spouse

Since each spouse needs their own attorney, the total cost is roughly double the per-spouse figure. Online prenup services cost $500—$2,000 but may not provide the same legal protection as a fully negotiated agreement.

Frequently Asked Questions

Can a prenup be changed after marriage?

Yes. Couples can amend a prenuptial agreement at any time during the marriage through a written, signed modification. Alternatively, they can replace the prenup entirely with a postnuptial agreement. Both parties must consent, and the same enforceability requirements (voluntariness, disclosure, fairness) apply.

Will a prenup hold up in court if we didn’t use lawyers?

It depends on the state, but the risk of invalidation increases significantly without independent legal counsel. Courts in states like California (under the UPMAA) require that each party either had an attorney or was advised in writing to seek one and expressly waived that right. Even in states without a strict attorney requirement, a judge is more likely to void a prenup if one party was unrepresented.

Does asking for a prenup mean the marriage is doomed?

Research suggests the opposite. A 2023 study from the American Academy of Matrimonial Lawyers found that couples who discuss finances openly before marriage — including through prenup negotiations — report higher relationship satisfaction. The prenup process forces transparency about assets, debts, and financial expectations that many couples otherwise avoid.

How Untie Can Help

A prenup is only as strong as the financial disclosure behind it. If one party conceals accounts, undervalues a business, or fails to disclose cryptocurrency holdings, the agreement could be voided years later. Untie’s asset-tracing technology provides a verified snapshot of each party’s financial position, helping attorneys ensure full disclosure and protecting the enforceability of the agreement.