A postnuptial agreement is a legal document signed after marriage or civil partnership that sets out how a couple’s money, property and assets would be divided if they later divorce. It works in the same way as a prenuptial agreement, except it’s entered into once the couple is already married — there’s no deadline for signing one, and it can be put in place at any point during the marriage.
Our family law solicitors draft and review postnuptial agreements for couples across London, including those where one partner has substantially greater assets or income, business owners protecting a company built before or during the marriage, and couples with children from a previous relationship who want to ring-fence assets for inheritance. We offer a free initial consultation.
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What is a postnuptial agreement?
A postnuptial agreement (or “postnup”) is a contract entered into by a married couple, or civil partners, that records how their finances, property and assets would be divided if the marriage or partnership later ends. Couples typically consider one where:
- one party has substantially greater assets or income than the other, in the UK or abroad
- one or both partners want to protect assets owned before the marriage, including business interests, inheritances or family trusts
- one or both partners has children from a previous relationship and wants to protect assets for inheritance purposes
- circumstances have changed materially since the wedding — a new business, an inheritance, or one partner giving up work to raise children
Unlike a prenuptial agreement, a postnup can be signed at any time after the wedding — there’s no 28-day cut-off to worry about, though it’s still best not to leave it until a relationship is already under strain.
Are postnuptial agreements legally binding?
Not automatically — but they can carry substantial weight, and in some circumstances the courts treat them as binding in practice. The key case is MacLeod v MacLeod [2008] UKPC 64, where the Privy Council held that a postnuptial agreement could be upheld even where its terms differed from what a court would otherwise have ordered, provided both parties had independent legal advice and gave full financial disclosure. Two years later, Radmacher v Granatino [2010] UKSC 42 extended similar reasoning to prenuptial agreements, confirming that courts should give effect to a nuptial agreement freely entered into by both parties with a full understanding of its implications, unless it would be unfair to hold them to it.
In practice, this means a properly drafted postnup — one that meets the safeguards below — is likely to significantly influence, and often determine, the outcome if the marriage ends.
Reform update (2026): In June 2026, the government opened a consultation proposing “qualifying nuptial agreements” — a new category covering both pre- and postnuptial agreements that courts would be legally required to uphold, provided certain safeguards are met. This is a proposal, not yet law, but it reflects the direction the law has already been moving in since MacLeod and Radmacher.
What makes a postnuptial agreement more likely to be upheld?
- Independent legal advice — both parties should have their own solicitor, not a shared one, to ensure they fully understand the agreement’s effect
- Full financial disclosure — an honest exchange of financial information, with supporting documentation, setting out each party’s assets and income
- Provision for any children — the agreement should explain how children of the family will be provided for
- A review clause — ideally triggered by the birth of a child or a significant change in circumstances, such as either party becoming unable to work or a major shift in assets
- Fairness — the agreement should meet each party’s basic needs if the marriage ends, judged at the time the agreement is relied on, not just when it was signed
- No fraud, misrepresentation or undue pressure — the court will look at all the circumstances, including any pressure either party was under from each other or third parties
- Correct legal format — the document must follow specific legal formalities to be valid
What does a postnuptial agreement cost?
There’s no fixed price — cost depends on the complexity of your assets and how much negotiation is needed between both sides’ solicitors. Straightforward agreements with modest, easily documented assets generally cost less than those involving a business, overseas property, or family trusts. We offer fixed-fee quotes wherever possible, so you know the total cost upfront — ask us for a tailored quote at your free consultation.
What can a postnuptial agreement cover?
- Property or assets either partner owned before the marriage
- The family home
- Gifts, property or inheritance received during the marriage
- Money in joint bank accounts
- Money saved or earned during the marriage
- Jointly purchased property
- Personal belongings owned before, or acquired during, the marriage
- Pensions
- Debts
- Maintenance payments for either party and any children of the family
- Which parent the children will live with
- What happens to assets if either party passes away during the marriage
What can’t a postnuptial agreement cover?
- Child custody or child maintenance — the court prioritises the child’s welfare at the time of any separation, not a prior agreement between the parents
- Clauses that encourage or expedite divorce — terms that appear designed to incentivise the marriage ending are unlikely to be upheld
- Anything manifestly unfair or contrary to public policy
When is the right time to see a solicitor?
A postnuptial agreement can be prepared at any point after you’re married. Both parties need enough time to gather financial information and take independent legal advice before signing — if there are overseas assets involved, allow extra time for specialist valuation or international legal advice. You should only sign a postnuptial agreement after receiving advice from a family law solicitor, not before.
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How does a postnuptial agreement differ from a prenup?
Only in timing. A prenuptial agreement is signed before the wedding and must be finalised at least 28 days beforehand to carry full weight. A postnuptial agreement is signed after the wedding, with no deadline. Both are assessed by the courts against broadly the same tests — free choice, full disclosure, independent advice, and fairness.
Why choose Adam Bernard for your postnuptial agreement?
- Years of experience handling and drafting postnuptial agreements for couples across London
- Specialist family law solicitors based in Central London (High Holborn) and East London (Upton Park), regulated by the Solicitors Regulation Authority
- Acute attention to detail, ensuring your agreement covers the eventualities that matter to your circumstances
- Free initial consultation, available in person, by phone, or via Zoom, Teams, WhatsApp or Skype
Get in touch with our expert Solicitors today.
Get in touch with our expert Solicitors today.
Frequently Asked Questions
Not automatically, but it can carry substantial weight. Following MacLeod v MacLeod (2008) and Radmacher v Granatino (2010), a postnup that's freely entered into, fully disclosed, and fair is likely to significantly influence — and often determine — the outcome if the marriage ends.
Cost depends on the complexity of your assets and the amount of negotiation required between both parties' solicitors. We offer fixed-fee quotes tailored to your circumstances following a free initial consultation.
No. Unlike a prenup, which should be signed at least 28 days before the wedding, a postnup can be entered into at any point after the marriage or civil partnership.
Yes. Independent legal advice for each party is one of the key factors courts consider when deciding how much weight to give a postnuptial agreement — sharing a solicitor significantly weakens its standing.
Yes. It's good practice to include a review clause, triggered by events such as the birth of a child or a significant change in circumstances, so the agreement can be updated to remain fair.
Only timing. A prenup is signed before the wedding; a postnup is signed after. Both are assessed by the courts against broadly the same tests of fairness, disclosure and independent advice.
No. Courts decide child arrangements based on the child's welfare at the time, not a prior agreement between the parents. A postnup can address financial provision for children but not who they live with as a matter of binding law.
Not yet. The government's June 2026 consultation proposes "qualifying nuptial agreements," covering both pre- and postnuptial agreements, that courts would be required to uphold. This is a proposal, not current law.
