Are Prenuptial Agreements Legally Binding in the UK?

Reviewed 30 October 2026 · England and Wales (Scotland differs) · General information, not legal advice

Not automatically, but close to it. Since Radmacher v Granatino (2010) courts hold couples to a prenup freely entered into with full understanding unless that would be unfair, so a properly prepared agreement usually decides the outcome.

Prenuptial agreements are not automatically binding in England and Wales, but since the Supreme Court's decision in Radmacher v Granatino in 2010 a court will normally hold a couple to an agreement that was freely entered into, with a full appreciation of its implications, unless it would be unfair to do so. In practice a properly prepared prenup, with disclosure, independent advice and provision for both parties' needs, is very likely to decide what happens on divorce, while a rushed or one-sided one may be given little weight. This guide explains the legal test, what a good agreement needs, what it can and cannot do, postnuptial agreements, costs, and the 2026 proposals to make qualifying agreements legally binding.

The law today: Radmacher v Granatino

Until 2010 the courts treated nuptial agreements with suspicion, as attempts to oust their power to decide a fair division under section 25 of the Matrimonial Causes Act 1973. Radmacher v Granatino [2010] UKSC 42 changed that. The case concerned a husband who had signed an agreement before the wedding giving up any claim on his wife's family wealth and who later sought a large award. The Supreme Court held that the court should give effect to a nuptial agreement that is 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 the parties to it.

Three things follow. First, a prenup cannot remove the court's jurisdiction: the judge still decides, and the agreement is one of the circumstances of the case, albeit often the decisive one. Second, the court asks whether each party understood what they were signing and chose to sign it, which is where disclosure, advice and timing come in. Third, fairness is judged at the time of the divorce, not the wedding: an agreement that was reasonable when signed may be unfair twenty years and three children later, particularly if it leaves one spouse unable to meet their needs. Children's needs always come first and no agreement can bargain them away.

Where the agreement is fair, the courts have repeatedly enforced terms that produced a much smaller award than the sharing principle would have given. And since Standish v Standish [2025] UKSC 26 confirmed that only matrimonial property is shared, a prenup that records which assets are to stay separate reinforces the position the law already takes. See how assets are divided on divorce for the background principles.

What makes an agreement likely to be upheld

There is no statutory checklist yet, but the courts, the Law Commission's 2014 recommendations and the 2026 reform proposals all point to the same safeguards:

1. Full financial disclosure by both parties, usually in a schedule attached to the agreement. Neither needs to see every bank statement, but each must know broadly what the other owns and earns.
2. Independent legal advice for each party from a different solicitor, confirmed in a certificate signed by the adviser. The wealthier party commonly pays for both.
3. Time. Sign at least 28 days before the wedding, the benchmark the Law Commission proposed; agreements signed on the eve of the ceremony invite the argument that there was pressure. Start three to four months ahead.
4. No duress, undue influence or misrepresentation. An ultimatum delivered after the invitations have gone out is a classic weakness.
5. Fair provision, especially for needs. The agreement should leave each party housed and able to live reasonably if the marriage ends, with better provision the longer it lasts, and should not restrict claims for children.
6. Review clauses: a commitment to revisit the agreement on the birth of a child, after a set number of years or on a major change in finances, often with a confirmation signed after the wedding.
7. Formalities: executed as a deed, signed and witnessed, in a language both parties understand, with foreign law considered where either party has assets or a connection abroad.

An agreement that meets every one of these is not guaranteed to be enforced, but one that fails several of them is likely to carry little weight.

What a prenup can and cannot do

A prenuptial agreement can define which assets are to be treated as non-matrimonial and kept by their owner: property owned before the marriage, inheritances received or expected, gifts from family, interests in a family business or trust, and the growth in value of all of these. It can set out how the family home will be dealt with, how debts are allocated, what each party will receive on divorce after different lengths of marriage, and whether either will seek maintenance. It can also address what happens on death, although that should be matched by wills: marriage revokes any earlier will unless it was made in contemplation of that marriage. See wills, trusts and probate explained.

It cannot bind the court on arrangements or maintenance for children. Child maintenance follows the statutory formula whatever the agreement says, and a court can order more if a child's needs require it; see how child maintenance is calculated. It cannot leave a spouse in real need, and it cannot stop either party applying to the court. The same principles apply to pre-registration agreements between civil partners.

Postnuptial agreements

A postnuptial agreement is made after the wedding. The Radmacher test applies in the same way, and because the parties are already married there is no wedding-day pressure to argue about, though the court still looks for disclosure, independent advice and fairness. Postnups are used where a prenup ran out of time, to confirm a prenup after the wedding, after a reconciliation, when one spouse receives an inheritance or sells a business, or when money is being put into a spouse's family asset and everyone wants certainty about what happens if the marriage fails. A separation agreement reached when a marriage has already broken down is different again: it records terms to be turned into a consent order.

Who should consider one, and what it costs

A prenup is worth considering where one or both of you is bringing significant assets into the marriage, expects an inheritance, owns a business or farm whose other stakeholders need protecting, has children from an earlier relationship whose inheritance you want to preserve, or where there is a large gap in wealth or income. Second marriages are the commonest reason; business owners and families with inherited property are the next. Couples with similar assets and no children from previous relationships gain much less from one.

Costs depend on complexity. A straightforward agreement drafted by a solicitor commonly costs between about £1,000 and £3,000 plus VAT, with the other party's independent advice an additional cost from several hundred pounds upwards; agreements involving businesses, trusts, overseas assets or international couples cost considerably more. Online fixed-fee services exist at the lower end, but an agreement is only as strong as the disclosure and advice behind it, so check what the fee includes. Family law solicitors usually quote a fixed fee once they know the asset picture; compare firms through family law solicitors in Bristol or the solicitors near me search, and start the process at least three months before the wedding. For an overview of what the family courts handle, see what family law covers.

Reform: the 2026 consultation on binding agreements

In February 2014 the Law Commission recommended qualifying nuptial agreements that would bind the courts if made as a deed, signed at least 28 days before the wedding, with material disclosure and independent legal advice, provided they did not leave either party unable to meet their financial needs. Successive governments did nothing with it. The Ministry of Justice has now revived the idea: its consultation paper A fairer end to relationships, open from 5 June to 14 August 2026, proposed making qualifying agreements binding with those safeguards, assessing needs on a narrower basis if an agreement is challenged, and counting seamless pre-marital cohabitation towards the length of the marriage. The outcome had not been published by 30 October 2026 and there is no Bill, so Radmacher remains the law. An agreement drafted today to the qualifying standard should satisfy both the current test and any future statute.

Scotland is different: prenups there are treated as ordinary contracts and are generally enforceable, subject to the court's power under the Family Law (Scotland) Act 1985 to set aside an agreement that was not fair and reasonable when it was made. Northern Ireland takes a similar approach to England and Wales.

Common mistakes and next steps

• Signing in the last fortnight before the wedding, or presenting the agreement as a condition of going ahead at that stage.
• Using one solicitor for both of you, or none.
• Hiding or understating assets, which can undermine the whole agreement.
• Drafting terms that leave one party with nowhere to live if the marriage ends after children arrive.
• Never reviewing it. Ten years, two children and a house move later, an unreviewed prenup is vulnerable.
• Forgetting wills, pension nominations and life insurance, which do not follow the agreement automatically.

If you are planning to marry and either of you has assets to protect, raise it early, gather your financial information, and each instruct a solicitor well before the invitations go out. Couples living together with no plans to marry face a different problem, explained in the common law marriage myth.

Frequently asked questions

Can a prenup be overturned?

Yes, if the court decides it would be unfair to hold the parties to it. The usual reasons are that one party did not understand it or was pressured, that assets were hidden, or that circumstances have changed so much that the agreement leaves a spouse or the children without what they need. A fair agreement made with disclosure, advice and time is rarely set aside.

Do both of us need a solicitor?

Each of you should have your own, and the agreement should record that you did. One solicitor cannot act for both because your interests conflict. Independent advice is the strongest evidence that each party understood the implications, which is the heart of the Radmacher test, and it would be a condition of a binding agreement under the 2026 reform proposals.

What if we signed the prenup a week before the wedding?

It is not void, but it is weaker. The court will look hard at whether the party giving up rights had a real choice and understood the terms. Signing a confirmation or a postnuptial agreement after the honeymoon, when the pressure has gone, repairs much of the damage, as does evidence that the terms had been negotiated and advised on for months beforehand.

Does a prenup protect an inheritance received during the marriage?

It can. Inherited assets are non-matrimonial in any event, so they are not shared unless treated as family assets, but a prenup stating that future inheritances stay with the recipient, and keeping them in separate names and accounts, makes the position far clearer. The protection is not absolute: if the other spouse's needs cannot be met otherwise, the court can still use inherited wealth.

Is a prenup signed abroad valid in England?

It will be considered under the same Radmacher test; the agreement in that case was itself made under foreign law. The court asks whether both parties understood it and whether it is fair now. Where either of you has assets or a connection abroad, have a solicitor check that the agreement works in each country concerned, because enforcement rules differ.

Can we change the prenup after we marry?

Yes, by a postnuptial agreement signed by both of you with the same safeguards: disclosure, independent advice and no pressure. Many prenups include review clauses requiring exactly that after a child is born or after a set period. An agreement that is reviewed and reconfirmed as life changes is far more likely to be upheld than one left untouched for decades.

Related guides

• Financial Settlements on Divorce: How Assets Are Divided
• Common Law Marriage Is a Myth: The Legal Rights of Unmarried Couples
• What Is a Consent Order and Do You Need One?
• What Is Family Law?

This guide describes the law in England and Wales (Scotland differs) as at 30 October 2026. It is general information, not legal advice about your situation; the law and the figures it quotes change, so check the position with a solicitor before acting. LawFirms.co.uk is a directory and does not provide legal services.