When families separate, often two narratives arise: an agreement can avoid the “she said he said'' arguments by showing exactly what each party intended.
Pre and post nuptial agreements will not guarantee a particular outcome if your marriage breaks down. What a well-drafted agreement can do is carry significant weight with the court, and in many cases, determine the outcome. That distinction matters, and understanding it is the starting point for deciding whether an agreement makes sense for you.
What pre and post nuptial agreements actually do
Pre-nuptial agreements are made before a marriage or civil partnership. Post-nuptial agreements serve the same purpose but are entered into after the marriage or civil partnership has taken place, often when circumstances change, such as receiving an inheritance, starting a business, or where there was not enough time to prepare an agreement before the wedding.
Neither is automatically legally binding in England and Wales. However, since the Supreme Court's decision in Radmacher v Granatino [2010], courts are required to give significant weight to pre and post nuptial agreements that were freely entered into by both parties with a full understanding of the implications, provided it would not be unfair to hold them to it. In practice, a properly prepared agreement is highly likely to be upheld.
A court will not enforce an agreement that leaves either party unable to meet their reasonable needs, or that fails to provide adequately for any children. These safeguards are expected to remain in place under any future reform.
A note on reform
The Government launched a formal consultation in June 2026 proposing "qualifying nuptial agreements" that courts would be required to uphold if certain procedural safeguards are met. This is not yet law, and the Radmacher framework continues to apply in the meantime. We will keep clients informed as the position develops.
What makes an agreement hold up
For a pre or post nuptial agreement to carry weight, both parties should take independent legal advice from separate solicitors, provide full financial disclosure, and enter the agreement freely without pressure. Timing matters particularly for pre-nuptial agreements: an agreement signed very close to the wedding date risks being challenged on the basis of undue pressure. Allowing at least four to six weeks before the marriage is advisable; longer is better.
The process needs to be handled carefully. Handled badly, it can create anxiety and mistrust between parties at a time when the opposite is called for. Handled well, it gives both parties clarity and confidence.
Other agreements we draft
Pre and post nuptial agreements are not the only way to formalise financial arrangements. We also draft cohabitation agreements for unmarried couples, separation agreements for couples of all kinds who are separating, and parenting agreements. More information on arrangements for unmarried couples is on our cohabitation page.
Costs and timescales for pre and post nuptial agreements
Costs vary between agreements. The key factor is the approach both parties take: excessive scrutiny or disproportionate negotiation over hypothetical scenarios will increase costs significantly, often without improving the outcome. As a guide, you can each expect to pay a minimum of £4,000 to £8,000 plus VAT. Most pre and post nuptial agreements can be drafted and finalised within four to six weeks.
We're always happy to have a no-obligation chat about the way forward. Visit familylawcity.co.uk or call us on 020 4579 5360.
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When should I make the agreement?
There are no hard and fast rules as such, generally it takes between 4-6 weeks from start to finish. Ideally you should look to get the agreement drawn up and signed at least a month before you get married. The reason is simple: the closer to the marriage date, the harder it is to get any wrinkles ironed out, and there may be the suggestion that undue pressure was put on one party by the other. This could affect the validity of the agreement in the future.
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Are they binding?
Lawyer’s answer; yes and no. It depends on whether the agreement is considered “fair”. This is judged by the legal concept of fairness rather than your personal sense of that word. Fairness generally means meeting the parties needs at a minimum, but it can be more complicated and is fact dependent. This is why it is sensible to involve a solicitor.
If an agreement is fair, it is likely to be binding unless there is a very good reason for it not to be. This involves some crystal ball gazing about the future, but that is the nature of these agreements.
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Why bother if they aren't binding?
Good question! The advantage is a PNA will reduce risk and provide as much clarity as possible. If properly drafted and fair, it may be a central issue in any future dispute, and it’s up to the party who doesn’t want to follow the agreement to say why.
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Can I change the agreement in the future?
Yes, in fact most agreements state they should be reviewed from time to time to make sure they remain relevant and fair.
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I feel under pressure to sign, what can I do?
Don’t sign and speak to a lawyer immediately. If that feels extreme, make your views clear in writing, preferably by email so you can evidence what you felt, when and how you communicated this. But, a lack of legal advice is usually a marker for whether an agreement is actually fair, and whether you understand what you were agreeing to.
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We didn't get the paperwork sorted in time, what are my options?
No problem: instead of a pre-nuptial agreement, you can draft a post-nuptial agreement instead, or as well as, which is identical apart from the timing. In some situations this may be preferable, as it avoids the suggestion that pressure was a factor due to the timing and pressure of the forthcoming marriage.
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Can I draft my own, surely they are the same every time?
We all use templates, but it is vital the agreement reflects your situation and takes account of this, and more, does so in a way that is fair. Also, legal advice on the consequences is key in ensuring the agreement is understood and therefore binding. Otherwise, good luck!