Pre‑nups and post‑nups — enforceability in England and Wales

Introduction

Many couples use prenuptial and postnuptial agreements to manage financial expectations if a marriage breaks down. Courts in England and Wales now give weight to such agreements but they do not make them automatically binding. This guide explains how the law treats pre‑nups and post‑nups, the factors judges consider, relevant practical steps to strengthen an agreement and common pitfalls to avoid.

What are pre‑nups and post‑nups?

– Prenuptial agreement: a written contract entered into before marriage setting out how spouses will divide assets or deal with finances if they separate or divorce.

– Postnuptial agreement: a similar contract signed after marriage that records the parties’ financial arrangements or intentions during the marriage and on separation.

Couples use these documents to protect inheritances, business interests pensions, property or to set out a clean break on divorce. The agreements also help clarify expectations and reduce conflict.

Legal background and key principle

English law does not treat nuptial agreements as automatically binding like in some civil law jurisdictions. The leading authority comes from the Supreme Court decision in Radmacher v Granatino [2010]. The court held that a nuptial agreement negotiated freely and entered into with a full appreciation of its implications should ordinarily be upheld, unless the agreement would not be fair in the circumstances at the time of the court’s decision.

In practice the court applies the matrimonial finance rules, notably section 25 of the Matrimonial Causes Act 1973, which requires judges to consider factors such as the parties’ income, needs and standard of living, contributions and the welfare of any children. A nuptial agreement forms part of the factual matrix that the court will consider when deciding whether to depart from the agreement to achieve a fair outcome.

When will a court uphold a nuptial agreement?

The court will usually uphold a pre‑nup or post‑nup where the following features are present:

– Full and frank financial disclosure: Both parties disclosed their assets liabilities income and pensions before signing. The court expects disclosure that enables each party to understand the agreement’s consequences.

– Independent legal advice: Each party received independent legal advice from a qualified lawyer who explained the agreement and the implications of signing it.

– No duress or undue pressure: The agreement was entered into voluntarily without coercion undue pressure or exploitation of vulnerability.

– Sufficient time before marriage (for pre‑nups): The signing occurred with sufficient time to consider the terms free from last‑minute pressure. Signing on the eve of the wedding raises concerns about pressure.

– Fairness at the time of the decision: The agreement does not produce an unfair result when the court assesses circumstances on divorce, especially where it would leave one party and any children in significant need.

– Specific and clear drafting: The agreement sets out precise financial arrangements rather than vague or aspirational statements.

When will a court depart from a nuptial agreement?

A court may depart from a nuptial agreement or refuse to give it decisive weight where any of the following apply:

– The agreement fails to provide adequately for the parties’ or the children’s reasonable needs at the time of separation.

– The agreement resulted from misrepresentation concealment or incomplete disclosure of material facts.

– One party lacked capacity or suffered undue pressure when entering the agreement.

– Supervening events have made the terms unfair or impractical, such as a dramatic change in income illness or the birth of children where the agreement did not address such circumstances.

– The agreement contains foreign elements or choice of law provisions that the court regards as inappropriate in the circumstances, though such clauses are often considered if properly drafted.

Drafting and execution best practice to maximise enforceability

Follow these practical steps to make a nuptial agreement more likely to be upheld:

1. Start early

For pre‑nups begin negotiations well before the wedding. Give each party time to obtain advice and to consider alternatives. Last‑minute signature risks later challenge.

2. Secure independent legal advice

Ensure both parties receive separate independent legal advice from solicitors who specialise in family law. Each adviser should certify that they gave advice and that the client understood the agreement.

3. Ensure full financial disclosure

Prepare a schedule of assets, liabilities, income and pensions for both parties and attach it to the agreement. Include valuations where necessary and supporting documents such as bank statements pension summaries and property deeds.

4. Draft precisely and address contingencies

Draft the agreement to specify percentages, timing and mechanisms for division. Anticipate potential changes such as children, job loss long‑term illness and include tailored provisions or review clauses to adjust terms if circumstances change.

5. Consider fairness and needs

Address reasonable needs for property housing maintenance and children. An agreement that deliberately leaves one party impoverished or fails to protect children will likely fail.

6. Consider a review or cooling‑off period

Include a review mechanism or require reaffirmation of the agreement after a defined period of marriage, for example two or five years. This shows ongoing consent and awareness of changing circumstances.

7. Keep the process evidence based

Record the negotiation process, advice certificates, disclosure lists and any contemporaneous correspondence. Produce a clear paper trail to demonstrate voluntariness and informed consent.

8. Use specialist drafting support

Engage family law solicitors like us or specialist advisers to draft the agreement. Courts scrutinise informal or DIY documents more closely.

9. Consider tax and inheritance consequences

Get tax and estate planning advice where assets, trusts or inheritance issues feature. Align the agreement with wills and other estate documents to avoid unintended outcomes.

10. Think about international elements

If parties have assets or residency overseas include clear choice of law and jurisdiction clauses and obtain advice on how foreign courts might treat the agreement. Take specialist cross‑border legal advice where necessary.

Practical examples of clauses that help

– Detailed schedules of assets with valuations and statements of ownership

– Specific percentage splits or formulae for dividing property or investments

– Pension sharing mechanisms or agreed offset methods with clear calculations

– Provisions for lump sums or maintenance limited to a fixed period or conditional on remarriage

– Review clauses requiring mutual consent to vary the agreement after a set interval

How courts treat agreements involving children

Courts place children’s needs above contractual certainty. An agreement that attempts to fix financial terms in a way that will leave children without adequate support will usually receive limited weight. Where a nuptial agreement affects provision for children judges assess whether the agreement leaves the children’s reasonable needs met. If not, the court can set aside or vary the agreement as necessary to protect the children.

Post‑nups: are they stronger than pre‑nups?

Courts apply the same principles to postnuptial agreements as to prenuptial agreements. In some situations post‑nups receive similar or greater respect because both parties negotiated while married and circumstances may be clearer. Post‑nups can address events that occurred after marriage and allow for adjustment to changed circumstances, which often helps enforceability. However the same standards of disclosure voluntariness and fairness apply.

Challenging or defending a nuptial agreement: practical considerations

If you seek to challenge an agreement prepare evidence of non‑disclosure coercion incapacity or material change in circumstances. If you defend an agreement show that the other party understood the terms received independent advice and that the agreement remains fair in the present circumstances.

Costs and timing for disputes

Litigation about nuptial agreements forms part of ancillary relief proceedings in divorce or separate financial remedy proceedings. Disputes can increase time and legal costs substantially. Many couples avoid contested court action by negotiating settlements or using mediation and collaborative law to amend or confirm agreements.

When to get specialist advice

Seek specialist family law advice when:

– You plan a pre‑nup or post‑nup involving significant assets pensions business interests or trusts

– Children from the marriage or previous relationships have specific needs

– You have cross‑border assets or residency issues

– One party has limited English, impaired capacity or risk factors suggesting vulnerability

Conclusion and practical checklist

Nuptial agreements can provide clarity and protect assets but they require careful drafting full disclosure and independent legal advice to carry weight in court. Courts in England and Wales now respect properly negotiated agreements but retain discretion to set aside or vary terms that prove unfair, especially for children.

Quick checklist to maximise enforceability

– Begin negotiations early and avoid last‑minute signing

– Obtain independent legal advice for both parties and retain certificates

– Prepare full, contemporaneous financial disclosure and attach schedules

– Draft clear, detailed provisions and include fallback or review clauses

– Consider children’s reasonable needs and provide accordingly

– Keep a complete record of negotiations advice and execution

– Update agreements after major life changes and align wills and estate plans

If you follow these steps you increase the chances that a pre‑nuptial or post‑nuptial agreement will carry significant weight if the court examines it in later proceedings. For tailored drafting and legal advice consult a specialist family solicitor who can align the agreement with your circumstances and reduce the risk of future challenge.

At Alexander JLO we have many years of experience of dealing with all aspects of family law and will be happy to discuss your case in a free no obligation consultation. Why not call us on +44 (0)20 7537 7000, email us at info@london-law.co.uk or get in touch via the contact us button and see what we can do for you?

This blog was prepared by Alexander JLO’s senior partner, Peter Johnson on 5th November 2025 and is correct at the time of publication. With decades of experience in almost all areas of law Peter is happy to assist with any legal issue that you have. He is widely regarded as one of London’s leading divorce lawyers. His profile on the independent Review Solicitor website can be found Here