Prenuptial and Postnuptial Agreements: Planning for Love, Life, and Legal Certainty

Paradigm Family Law

February 2, 2026

In the whirlwind of excitement that comes with engagements, wedding planning, or preparing for a life together, one topic is often overlooked: prenuptial and postnuptial agreements. While not as romantic as choosing a venue or planning a honeymoon, they are conversations worth having for couples who want clarity and security.

This is not a modern or cynical idea. One of the most influential family law cases in England and Wales arose from exactly this situation. The Radmacher family sat down in Düsseldorf, before a German notary, to discuss their financial arrangements calmly and openly before marriage. That agreement later shaped how English courts approach nuptial agreements.

Prenuptial and postnuptial agreements are not about planning for failure. They are about transparency, collaboration, and making informed decisions at a time when both partners can engage constructively.

What Is a Prenuptial Agreement?

A prenuptial agreement is a legal contract entered into before marriage or a civil partnership. It sets out how finances and assets would be treated if the relationship were to end.

This modern approach follows the Supreme Court decision in Radmacher v Granatino, which confirmed that nuptial agreements should be given decisive weight where entered into freely, with full understanding, and where it would not be unfair to do so at the time they are relied upon.

A prenuptial agreement can deal with assets owned before marriage, inheritances, family wealth, business interests, responsibility for debts, and expectations around spousal maintenance.

In England and Wales, prenuptial agreements are not automatically legally binding. However, the courts will usually give them significant weight where both parties entered into the agreement freely, with full financial disclosure, independent legal advice, and terms that remain fair at the time of separation.

What Is a Postnuptial Agreement?

A postnuptial agreement serves the same purpose as a prenuptial agreement but is entered into after marriage.

Postnuptial agreements are commonly used where circumstances change during a marriage. This may include the birth of children, one spouse giving up work, receiving an inheritance, starting or expanding a business, or planning an international move.

When properly prepared, postnuptial agreements can carry similar legal weight to prenups and are often the most appropriate option for couples who are already married.

Are Prenuptial and Postnuptial Agreements Legally Binding in England and Wales?

Prenuptial and postnuptial agreements are not automatically binding, but the legal position has evolved significantly.

Following the Supreme Court decision in Radmacher v Granatino, the court confirmed that a nuptial agreement should be upheld where it was entered into freely, with full understanding, and where it would not be unfair to do so at the time it is relied upon.

In practice, this means a well-drafted prenup or postnup often plays a decisive role in shaping financial outcomes on divorce, even though the court retains overall discretion.

Why More Couples Are Considering Prenuptial and Postnuptial Agreements

One of the main reasons nuptial agreements have become far more common is that people are marrying later in life.

Many couples now marry in their thirties, forties, or later, often after years of building a career, buying property, accumulating savings, or developing business interests. It is also increasingly common for couples to have lived together, owned assets separately, or had children before marriage.

As a result, couples frequently enter marriage with unequal financial starting points. One partner may already own a home, have substantial savings, or run a business, while the other may have fewer assets or may step back from work to support family life.

A prenuptial or postnuptial agreement allows couples to acknowledge this imbalance openly and decide together how it should be treated. Some choose to ring-fence assets built up before marriage. Others agree how assets should be shared over time or how contributions during the marriage should be recognised.

This is not about one partner protecting themselves at the expense of the other. It is about transparency, fairness, and managing expectations from the outset.

Collaboration and Transparency

A nuptial agreement works best when approached collaboratively.

Open discussion helps ensure the agreement feels fair and balanced rather than imposed. This reduces resentment and makes it more likely the agreement will be respected if it is ever relied upon.

Approached properly, working together on a prenup or postnup can form part of building a strong foundation for married life.

Prenuptial and Postnuptial Agreements Before an Expat Move

For couples planning an international move together, this is one of the most important and most overlooked moments to put legal clarity in place.

Before leaving England and Wales to begin an expat life as a family, it is essential to consider what would happen if the relationship broke down abroad. Once you relocate, different legal systems may apply very different rules to finances and children.

Prenup or Postnup & Jurisdiction

If you are not yet married, a prenuptial agreement is usually appropriate.
If you are already married, a postnuptial agreement is normally the correct document.

Equally important is jurisdiction. An agreement drafted with England and Wales in mind may be treated very differently in another country. Some jurisdictions treat nuptial agreements as binding, while others do not.

Taking advice before you move allows you to choose the legal framework deliberately rather than reactively.

Questions to Address Before Leaving the UK

Putting a nuptial agreement in place before relocating allows couples to address which country’s courts would deal with divorce or financial claims, whether one parent could return to the UK with the children, and how relocation decisions would be viewed if there is later a dispute.

It also helps clarify what happens to assets that move abroad, including furniture, vehicles, household contents, overseas bank accounts, property, and income earned overseas.

Without planning, these issues are often resolved through urgent court proceedings, sometimes in more than one country.

Children, Relocation, and Returning to England and Wales

International family life carries particular risks where children are involved.

If a relationship breaks down overseas, a parent may assume they can return to England and Wales with the children. In many cases, that assumption is incorrect. International child abduction laws can apply even where the original move took place with consent.

While a nuptial agreement cannot override child welfare law, it can record shared intentions and reduce disputes about jurisdiction.

Prenuptial and Postnuptial Agreements for Business Owners

For business owners, entrepreneurs, and individuals with complex financial structures, nuptial agreements are often essential.

Divorce can place significant pressure on a business if ownership, valuation, or liquidity becomes disputed. Without advance planning, the court may require business assets to be realised or leveraged to fund a settlement, even where this risks destabilising the business.

A business-focused prenuptial or postnuptial agreement can ring-fence pre-marital business interests, distinguish personal assets from company assets, set agreed valuation approaches, and define how future growth or exit proceeds are treated.

For business owners, these agreements serve a similar function to shareholders’ agreements or succession planning. They introduce certainty, protect continuity, and reduce risk for third parties.

Practical Points to Remember

Each party should take independent legal advice. Full and honest financial disclosure is essential. International and tax advice may be required where assets or family life cross borders. Agreements should be reviewed if circumstances change.

Prenuptial and postnuptial agreements are not about betting against a relationship. They are about responsible planning for modern lives.

Speak to a Specialist Family Lawyer

If you are considering a prenuptial or postnuptial agreement, particularly ahead of an international move or where business assets are involved, early advice is critical.

Paradigm Family Law offers a free initial consultation and fixed-fee solutions, giving clarity on cost from the outset. The team advises clients across England and Wales, including those with international, business, and high-value financial arrangements.

To speak with Frank Arndt or Evelyn Peacock, call 01904 217225 or email info@paradigmfamilylaw.co.uk.