The Modern Couple’s Guide to Pre- and Post-Nups

When planning a life together, the last thing most couples want to talk about is what happens if things fall apart. But as family lawyer Sital Fontenelle notes: “One of the biggest misconceptions is that prenups are only for the ultra-wealthy. In reality, they are a reliable way to ensure you’re aligned something as fundamental as finances and, most of all, helps to reduce conflict and legal costs further down the line if the marriage ends.”

Based in London and specializing in cross-border cases, Fontenelle often sees just how emotionally and legally complex things can become. Especially when international jurisdictions or (future) children are involved. With around 40 to 50 percent of marriages ending in divorce in both the US and parts of Europe, a well-structured prenuptial or postnuptial agreement can offer more than legal clarity, it can be an act of care.

Yes, the conversation can feel tricky to navigate at first, but it is essential. As therapist and relationship coach Jillian Turecki, whom we have spoken with before, explains: “How you talk about money reveals a lot. Do emotions surface? Are there triggers? This can be a litmus test for your relationship’s resilience.”

So how do you approach the prenup talk with grace, and get the legalities right without losing the love? We asked the experts at Kingsley Napley LLP.

What Is A Prenup, What Is A Postnup?

A prenup is signed before the marriage, a postnup after. Both are contracts between two people, created to outline how assets, income, or responsibilities will be handled in the event of a divorce. “They’re called ‘nuptial agreements’ because they relate to the marriage itself,” explains family lawyer Sital Fontenelle. “They’re not about distrust. They’re about clarity.”

What Is the Difference Between a Prenup and a Postnup?

While prenuptial agreements are ideal, setting everything out before vows are exchanged, not every couple gets there in time. “People evolve. Circumstances shift. And sometimes couples don’t know to have those conversations until after they’re already married,” explains Fontenelle. That’s where a postnup comes in. Often, it follows a major change: an inheritance, the launch of a business, one partner stepping away from work to care for children. In some cases, it brings renewed structure after a period of strain. A way to re-enter the marriage with shared understanding and rebalanced expectations. The key difference lies in timing. A prenup is signed before marriage, a postnup once the legal union has begun. But both require the same things: disclosure of finances, mutual consent, and independent legal advice. “For some couples, a postnup is a form of care,” Fontenelle says. “It says: I want us both to feel secure, even if the future changes.”

“They’re called ‘nuptial agreements’ because they relate to the marriage itself,” explains family lawyer Sital Fontenelle. “They’re not about distrust. They’re about clarity.”

Rising Demand in Nuptial Agreements

It is a shift that Fontenelle has observed over the past few years and it seems to reflect a deeper change in how couples relate not only to one another but also to the idea of marriage itself. It is no longer just about romance or tradition. There is a growing desire to move through these milestones with clarity, mutual respect, and intention.

“We’re seeing a sharp increase in clients asking about nuptial agreements,” says Fontenelle. While in the US, in a number of states, nuptial agreements have been legally binding for some time, in England that key turning point came in 2010 with the landmark Radmacher ruling by the UK Supreme Court. For the first time, prenuptial agreements were to be given significant legal weight, provided both parties had freely entered into the agreement and fully understood its implications.

The Inheritance Era

Not to mention, there is a significant wealth transfer happening, says Sital. More couples are entering marriage with inheritances underway, gifted assets, or early investments already in place. People are inheriting from parents and grandparents, receiving financial gifts, and modernising their assets through trusts or early business success.

Changing Financial Dynamics in Relationships

What’s more, the traditional roles in relationships are shifting too. According to Fontenelle, she now sees more women arriving in her office not just as partners, but as full wealth holders. “More women now are controlling wealth,” she says. “They’re starting businesses, investing, earning more. There’s a rise in dual‑income households, where both partners contribute equally, or in some cases, the woman is the primary earner.” This isn’t anecdotal. Recent data shows that by 2025, women in the UK are expected to control about 60% of total wealth. Yet a significant gap remains: men still hold around 90% more pension wealth and on average 35% more total wealth than women. That disparity stems from factors like part-time work, caregiving breaks, lower pensions, and fewer investment assets.

From Safety Net to Shared Statement

In this evolving landscape, nuptial agreements feel less like a safety net and more like a statement of agency. Especially for couples reimagining financial partnership in modern marriage.

Why Everyone Should Really Consider a Prenup

“Most people think of prenups as a way for the wealthier partner to protect themselves,” says Fontenelle. “But that’s a narrow view. In truth, they can serve both partners. Financially, emotionally, and practically.” A prenuptial agreement is not a prediction of failure. It’s a tool for clarity. And for many couples, it’s a way to start the conversation about how they plan to move through life. Together, with awareness.

Here’s What a Prenup Can Offer:

Protection of Family or Inherited Wealth

Let’s start with the obvious: from family homes to trusts, a prenup can help ensure generational assets are preserved with clear intent.

Clarity Around Expectations

It opens the conversation early. “If one partner is taking a career break, moving countries, or making a financial sacrifice, a prenup helps define how that contribution will be honored,” explains Fontenelle.

Business Protection

Entrepreneurs often want to protect the early, high-risk years of a startup. “You don’t want to sell or dilute a company just to divide it,” says Fontenelle. “But many are happy to share the family home or other joint assets.”

Safeguarding Children and Future Generations

“If there’s no clarity, wealth intended for children or grandchildren can easily become entangled,”says Fontenelle. Whether it’s a family home, a trust, or a long-held asset, a prenup can record what was meant for legacy and what’s shared. It also protects children emotionally: reducing drawn-out court battles helps preserve a sense of stability. “Children pick up on stress and conflict at any age,” she adds. “Anything that softens that impact matters.”

A Roadmap for Complex Family Dynamics

For those entering a second or third marriage (what Fontenelle calls the “silver splitters”) a prenup offers structure. It protects children from previous relationships and ensures clarity about future intentions.

Reduced Litigation in Case of Divorce

“So much of what we do during divorce,” Fontenelle notes, “is piecing together what the intention was. A prenup documents that from the start, which often avoids painful and expensive court battles.”

Clarity in International Relationships

For couples who live, marry, or move between different countries, a prenup can reduce confusion if things unravel.“Even before assets are discussed, there’s often a fight over which country the divorce should happen in,” explains Fontenelle. Some countries, like France or certain U.S. states, will uphold the original agreement. Others, like England, may apply discretion and step in where there is a real predicament of need. Including a clause about jurisdiction can save months of expensive cross-border litigation.

Protecting Privacy

Without an agreement in place, a high-conflict divorce may end up in court. In some jurisdictions, the media can access and report on financial disclosures, even for private individuals.“People often end up settling for more or less just to avoid their lives becoming searchable,” says Fontenelle. The (Paul) McCartney–Mills divorce is a cautionary tale: their judgment was made public, exposing personal and financial details. A prenup can support private resolution through arbitration, keeping matters out of court and out of the press.

Whether you’re weeks away from getting engaged or simply daydreaming about it, there is a quiet romance in planning for what could be. Practically, kindly, and consciously. That includes understanding the facts about prenups and postnups.

Read more from our Decoding Prenups & Postnups series

When to Discuss a Prenup, and What It Should Include

How This Couple Approached Their Prenup With Honesty and Balance