Prenups: what they cover and how to talk about money before marriage

What is a prenup, and what happens without one?

A prenup lets a couple replace some of the default rules that would otherwise apply to their money. A postnup is the same idea signed after the wedding.

Without one, the law of where you live decides. In the US, nine states are community property states, according to the IRS: Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington and Wisconsin. There, income and property acquired during the marriage are generally treated as belonging to both spouses. Other states apply their own division rules. In England and Wales, there is no fixed formula: on divorce, a judge decides how to divide money and property under the Matrimonial Causes Act 1973, and a prenup is one of the circumstances the judge weighs.

Who tends to think about a prenup? People who own a business or a home before marrying, expect an inheritance, have children from a previous relationship, earn very different incomes, or carry significant debt. But the conversation that leads to a prenup is useful to every couple, whether or not they sign one.

What a prenup can and can’t cover

Section 3 of the Uniform Premarital Agreement Act (UPAA) lists what the parties may agree on. State versions differ, but the list gives a good picture:

Spousal support is where states differ most. In California, for instance, a clause about spousal support, including a waiver, can’t be enforced unless the spouse giving it up had an independent lawyer when signing, and can be set aside if it’s unconscionable when enforcement is sought.

Debts belong in the conversation too. A prenup can say that each spouse stays responsible for debts they bring into the marriage or take on alone. It can’t bind the lender, though: if you both sign a loan, the bank can still pursue either of you.

When a US court may refuse to enforce a prenup

Under section 6 of the UPAA, a prenup isn’t enforceable if the spouse challenging it proves either:

1. they didn’t sign it voluntarily; or
2. it was unconscionable when signed and, before signing, they didn’t receive fair and reasonable disclosure of the other’s property and debts, didn’t waive that disclosure in writing, and couldn’t reasonably have known about it.

The UPAA dates from 1983. By 2012, the Uniform Law Commission counted 26 jurisdictions that had adopted it, about half with significant changes. That year it published a successor, the Uniform Premarital and Marital Agreements Act, which adds requirements such as access to independent legal representation and a plain-language notice of the rights being waived. Colorado is one state that has adopted it. Because states have changed these rules in different ways, check the version that applies where you live.

Timing counts. The UPMAA’s commentary notes that an agreement presented hours before the wedding, with guests already arrived, clearly raises issues of duress. California goes further: for agreements signed since 2020, the spouse against whom the prenup is enforced must have had at least seven calendar days between first seeing the final agreement and signing it, and must have had independent counsel or waived it in a separate writing.

England, Wales and Scotland

England and Wales. In Radmacher v Granatino (2010), a German woman and a French man had signed a prenup in Germany before marrying in London. On their divorce, the UK Supreme Court upheld the agreement by eight judges to one, with Lady Hale dissenting. The majority set the test still used today: courts should uphold an agreement that each spouse entered freely and with a full understanding of its consequences, unless holding them to it would be unfair in the circumstances. The needs of the spouses and especially of the children remain central.

Resolution, the association of family lawyers in England and Wales, recommends signing as far ahead of the wedding as possible, ideally not less than 28 days before, after exchanging full financial disclosure and with independent legal advice for both.

Reform is under way. The Law Commission recommended in 2014 that “qualifying nuptial agreements” become binding, subject to safeguards, without allowing couples to contract out of meeting each other’s financial needs. In June 2026, the Ministry of Justice opened a consultation, “A fairer end to relationships”, which closed on 14 August 2026 and includes introducing binding qualifying nuptial agreements with safeguards so that decisions are fully informed and freely made. Until any law changes, the Radmacher test applies.

Scotland. The rules are different. Under section 16 of the Family Law (Scotland) Act 1985, a court can set aside or vary an agreement on financial provision if it was not fair and reasonable at the time it was entered into. Take Scottish advice if you live there.

How to get a prenup that holds up

How to talk about money before marriage

Many couples who never sign a prenup still benefit from the conversation. Pick a calm moment, set an hour aside, and put numbers on the table rather than impressions.

A few ground rules help. Talk about how money was handled in your families growing up; it explains a lot of reactions. Separate facts (the balance on a card) from judgments (“you’re bad with money”). Agree on a number above which you check with each other before spending. And come back to it once a year, because incomes, families and goals change.

For the day-to-day side, see three ways to run a couples budget, and for what to update once you’re married, money at every stage of life.

Once you’ve decided, write it down where you’ll both find it. In a shared Binome360 assistant, each of you adds from your own phone:

Frequently asked questions

What is a prenup?

A prenuptial agreement is a written contract two people sign before marrying. It sets out how their property, debts and sometimes spousal support will be handled if the marriage ends by divorce or death, in place of some of the default rules where they live.

Are prenups legally binding in the UK?

In England and Wales, not automatically, but courts give effect to an agreement freely made with a full understanding of its implications unless it would be unfair to hold the couple to it (Radmacher, 2010). In Scotland, an agreement can be set aside if it wasn’t fair and reasonable when made. The government consulted in 2026 on making qualifying agreements binding in England and Wales.

Can a prenup include child support or custody?

It can’t reduce a child’s right to support, and courts decide custody based on the child’s interests at the time. The UPAA and state laws such as California’s say so explicitly.

Does a prenup protect me from my spouse’s debts?

It can set out who is responsible for which debts between the two of you. It doesn’t bind lenders: on any loan or card you both signed, the lender can pursue either of you.

How far before the wedding should you sign a prenup?

As early as possible. In England and Wales, family lawyers recommend at least 28 days. In California, the law requires at least seven days between receiving the final text and signing it. Last-minute agreements invite challenges for duress.

In short

A prenup is a contract about money that each of you should understand, negotiate with your own lawyer and sign well before the wedding. It can settle property, debts and often spousal support, never child support. Even if you don’t sign one, have the conversation. First action: each of you writes down your assets, debts and income this week, then swap lists.

Sources

• Uniform Law Commission, Uniform Premarital Agreement Act (1983), sections 2, 3 and 6: uniformlaws.org.
• Uniform Law Commission, Uniform Premarital and Marital Agreements Act (2012), prefatory note and comments: ulc.wa.gov; Colorado Revised Statutes §§ 14-2-301 to 14-2-313: law.justia.com.
• California Family Code, sections 1612 and 1615: leginfo.legislature.ca.gov.
• IRS, Publication 555, Community Property: irs.gov/publications/p555.
• UK Supreme Court, Radmacher (formerly Granatino) v Granatino [2010] UKSC 42, judgment of 20 October 2010: supremecourt.uk.
• Resolution, “Guidance note: preparing pre- and post-marital agreements”, reviewed April 2026: resolution.org.uk.
• Law Commission, Matrimonial Property, Needs and Agreements (Law Com No 343), 2014: lawcom.gov.uk.
• Ministry of Justice, “A fairer end to relationships” consultation, 5 June to 14 August 2026: gov.uk.
• Family Law (Scotland) Act 1985, section 16: legislation.gov.uk.
• Federal Trade Commission, “You now have permanent access to free weekly credit reports”, October 2023: consumer.ftc.gov.

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