Radmacher v Granatino [2010] UKSC 42 is the Supreme Court decision that gave prenuptial and postnuptial agreements real weight in England and Wales for the first time. By a majority of eight to one, the court held that judges should give effect to a nuptial agreement freely entered into by each party with a full appreciation of its implications, unless in the circumstances prevailing it would not be fair to hold them to it.1The Supreme Court of the United Kingdom. Radmacher v Granatino Judgment The ruling did not make prenups binding contracts, and it did not remove the family court’s power to divide finances on divorce. What it changed is the starting point: a properly made agreement now commands serious weight, and the spouse who wants to escape its terms has to explain why.
What the Supreme Court Actually Decided
The majority’s test has three parts folded into a single sentence. A court should give effect to a nuptial agreement that was, first, freely entered into by each party; second, entered with a full appreciation of its implications; and third, not unfair to enforce in the circumstances prevailing at the point of divorce.1The Supreme Court of the United Kingdom. Radmacher v Granatino Judgment
That formulation sits on top of, rather than replaces, the statutory framework in section 25 of the Matrimonial Causes Act 1973. Section 25 requires the court to consider “all the circumstances of the case,” with the welfare of any minor children as the first consideration, and to weigh factors including each party’s income, earning capacity, needs, the standard of living during the marriage, its duration, and the contributions each spouse made, including non-financial ones like homemaking and childcare.2Legislation.gov.uk. Matrimonial Causes Act 1973, Section 25 The statute says nothing about prenuptial agreements. The Supreme Court’s reasoning bridged that silence: because section 25 directs courts to consider all the circumstances, a nuptial agreement the parties freely chose to sign is plainly one of them.
The Facts That Produced the Ruling
Katrin Radmacher, heiress to a substantial German paper industry fortune, married Nicolas Granatino, a French investment banker working in London, in 1998. Before the wedding, they signed a prenuptial agreement in Germany before a notary. It stated that neither would seek maintenance or a share of the other’s assets if the marriage ended. The agreement was valid under German law. No financial disclosure accompanied it. Mr Granatino did not receive independent legal advice.3Practical Law. Supreme Court Upholds Pre-Nuptial Agreement in Radmacher Case
They had two children and separated in 2006. By then Ms Radmacher’s wealth was estimated at around £100 million. Mr Granatino had left his role at J.P. Morgan, where he earned around £120,000 a year, to pursue academic research in biotechnology at Oxford on roughly £30,000.
At the High Court, Baron J awarded Mr Granatino approximately £5.56 million, treating the prenup as of diminished importance because he had not received legal advice and the agreement made no provision for children. The Court of Appeal reversed much of that award, holding that the agreement should have carried decisive weight. The Supreme Court dismissed Mr Granatino’s appeal by eight to one, with Lady Hale as the sole dissenter.
Why the Ruling Mattered
Before Radmacher, prenuptial agreements in England and Wales were treated with near-automatic suspicion. Courts viewed them as attempts to oust the court’s own jurisdiction over financial remedies, so the spouse relying on the agreement had to justify giving it any weight at all.
Radmacher inverted that burden. A properly made agreement now starts with significant weight, and it falls to the spouse seeking to escape it to show why enforcement would be unfair. Prenups remain technically non-binding as a matter of contract law, because the court’s section 25 discretion cannot be signed away. In practice, though, the shift in who has to persuade the judge is what most family lawyers point to when explaining the case’s importance.
When a Court Will Still Override an Agreement
The Supreme Court drew on the strands of fairness identified in earlier decisions in White v White and Miller v Miller: needs, compensation, and sharing. Those three strands roughly map to when an agreement is most likely to be overridden and when it is most likely to be followed.
Needs
An agreement that would leave one spouse unable to meet basic housing and living costs while the other holds substantial wealth is unlikely to be enforced on its terms. The court reasoned that parties are unlikely to have intended their agreement to produce genuine hardship.1The Supreme Court of the United Kingdom. Radmacher v Granatino Judgment Needs extend to children: the court will ensure the primary carer has adequate resources to house them and provide a stable environment, whatever the agreement says.
Compensation
Where one spouse gave up a career or earning potential to look after the family, freeing the other to build wealth, it will generally be unfair to enforce an agreement that lets the wealth-building spouse keep everything. The court recognised that this kind of relationship-generated disadvantage deserves protection even when both parties signed away their claims in advance.
Sharing
Sharing is where a nuptial agreement carries the most force. When both spouses can meet their own needs and no compensation claim arises, the court is most likely to respect the agreement’s terms rather than impose an equal division. Radmacher itself fell squarely into this category. Ms Radmacher’s wealth was inherited and predated the marriage, Mr Granatino could meet his own needs through his earning capacity, and the agreement’s effect was primarily to exclude him from a share of assets he had not helped create.1The Supreme Court of the United Kingdom. Radmacher v Granatino Judgment
What Makes an Agreement Stick After Radmacher
The Supreme Court declined to lay down rigid procedural requirements. The judgment and subsequent practice point to several factors that strengthen an agreement’s standing.
Independent Legal Advice
Both parties should receive separate legal advice so each understands what rights they are giving up. What makes the Radmacher facts unusual is that Mr Granatino did not get any. The Supreme Court held this did not invalidate the agreement, because on his particular facts, as a sophisticated former investment banker, it had not affected his willingness to sign or his understanding of what he was signing.3Practical Law. Supreme Court Upholds Pre-Nuptial Agreement in Radmacher Case For most couples, the absence of legal advice would provide real grounds to challenge the agreement, and family lawyers now treat independent advice as a baseline.
Financial Disclosure
Each party should provide a complete picture of assets and income. Again, Radmacher itself was unusual. Ms Radmacher had not disclosed the approximate value of her wealth, but the court found that Mr Granatino clearly knew she was very wealthy and the absence of a precise figure had not affected his decision. Where a spouse genuinely did not understand the scale of the other’s wealth, incomplete disclosure could significantly undermine the agreement.
Timing and Absence of Pressure
An agreement signed days before the wedding raises obvious concerns about pressure. The Law Commission has recommended that agreements be signed at least 28 days before the ceremony.4Resolution. Guidance Note: Preparing Pre- and Post-Marital Agreements – Section: 6. Safeguards Where lead time is shorter, the question is whether one spouse was effectively forced into signing because pulling out so close to the wedding felt impossible. Courts look at the full picture rather than applying a mechanical deadline.
Provision for Children
An agreement that ignores the possibility of children is more vulnerable. The Radmacher prenup made no provision for them, and while the court upheld the overall approach, it ensured Mr Granatino received enough to house the children and meet their needs during their minority. Agreements that build in reasonable provision for future children tend to fare better as the marriage evolves.
Lady Hale’s Dissent
Lady Hale, the sole dissenter, delivered one of the most quoted dissenting opinions in modern English family law. Her objections went beyond the facts to challenge the majority’s approach at a structural level.
She argued that marriage is not simply a private contract but a legal status with consequences for the state and for third parties, carrying what she called an “irreducible minimum” of mutual support obligations. In her view, the majority’s formulation amounted to judicial rewriting of the section 25 framework, a job that properly belonged to Parliament and the Law Commission.1The Supreme Court of the United Kingdom. Radmacher v Granatino Judgment
She also raised a gender dimension the majority did not directly address. Prenuptial agreements, she pointed out, typically aim to deny the economically weaker spouse the provision they would otherwise receive, and that weaker spouse is usually, though not always, the wife. She noted the irony of the question being decided by a court of eight men and one woman. Her proposed test was subtly but meaningfully different: she would have asked whether it is fair to hold the parties to the agreement now, placing the fairness inquiry at the centre rather than treating it as an exception to a presumption of enforcement.
Where the Law Stands Now
Following the Supreme Court’s own suggestion that the area was ripe for legislative reform, the Law Commission carried out a full review. In 2014 it recommended the creation of “qualifying nuptial agreements,” which would be enforceable contracts provided certain procedural safeguards were met. Even qualifying agreements, the Commission proposed, should not be able to override either spouse’s financial needs.5Law Commission. Matrimonial Property, Needs and Agreements
Parliament has not acted. A Divorce (Financial Provision) Bill introduced by Baroness Deech in 2017 completed its passage through the House of Lords in December 2018 but stalled in the House of Commons. A similar bill introduced in 2021 did not progress past its first reading.6House of Lords Library. Law Relating to Prenuptial Agreements As of early 2025, there has been no government response to the Law Commission’s recommendations and no legislation on the horizon.
Radmacher therefore remains the governing authority, and the practical picture it produces is a sliding scale rather than a switch. Inherited and pre-marital wealth receives the strongest protection. Short marriages where both spouses remain financially independent tend to produce outcomes closely aligned with the agreement’s terms. Agreements become harder to enforce as marriages grow longer and circumstances change, particularly where children arrive and one spouse steps back from paid work. A couple who signed a prenup as childless professionals but went on to have three children, with one spouse leaving employment, presents a very different picture from the one contemplated in the original document, and courts have consistently held that the arrival of children can fundamentally alter the fairness analysis.