In the intricate world of family law, a prenuptial agreement (PNA) is often regarded as an important safeguard, a carefully drawn map of financial clarity designed to protect your pre-marital assets and future interests. Yet, in England and Wales, this “financial shield” can be more fragile than it seems.
Unlike in other jurisdictions, prenuptial agreements here are not automatically legally binding. They are persuasive documents that the court may uphold, but only if they pass an important set of criteria. Too often, even meticulously prepared PNAs unravel in the courtroom because of a handful of avoidable yet costly errors.
The difference between a prenuptial agreement that withstands judicial scrutiny and one that collapses under it often lies in the subtle missteps made long before a judge ever sees it.
Below, we unpack the most common reasons English courts invalidate PNAs, how to safeguard against them, and what recent case law teaches us about getting it right the first time.
The Four Fatal Flaws: Why English Courts Invalidate Prenups
1. The Fairness Trap: When Terms Become “Manifestly Unfair”
Fairness is the master key that unlocks or locks the enforceability of a PNA. A court may respect the agreement in principle, but if enforcing it would leave one party in genuine financial hardship, it will intervene.
The Mistake: Drafting a prenup that heavily favours one partner while leaving the other without adequate provision for housing, income, or future needs.
The leading case of Radmacher v Granatino (2010) established that while a freely entered PNA will usually be given decisive weight, it must not be unfair in the circumstances prevailing at the time of divorce.
The Judicial Focus:
- The reasonable needs of both spouses must be met.
- The best interests of any children must always take precedence.
- A PNA that disregards these considerations is on unstable ground.
The Takeaway: Build fairness into the structure of your agreement. Include provisions that ensure both parties’ essential needs are covered, housing, income, and any future dependants. A judge will respect an agreement that shows foresight and balance.
2. The Ticking Time Bomb: Pressure and Poor Timing
Timing can be fatal. Courts scrutinise not only the terms of the agreement but how and when it was signed.
The Mistake: Signing the PNA too close to the wedding day.
The recent case of Helliwell v Entwistle (2025) illustrates this vividly. The parties signed their prenup on the morning of their wedding, a decision that cost them dearly when the agreement was later challenged. The Court of Appeal confirmed that signing so late created a strong inference of undue pressure, undermining the voluntariness required for enforceability.
The Takeaway:
- The minimum safe period is 28 days before the ceremony.
This ensures both parties have time for reflection, negotiation, and independent advice, the hallmarks of true consent.
3. The Sin of Omission: Missing or Incomplete Financial Disclosure
A prenup is only as strong as the truth that underpins it. Courts expect full and frank financial disclosure, not approximations, not selective summaries, but a complete and verifiable picture of each party’s finances.
The Mistake: Concealing assets, providing vague estimates, or neglecting to update figures when financial circumstances change.
In Helliwell v Entwistle, one party’s failure to be transparent about their financial position was another key reason the agreement was struck down. The court emphasised that without complete disclosure, it is impossible to show that both parties fully understood the implications of what they were signing.
The Takeaway:
Attach a detailed financial schedule to your agreement. It should include:
- Assets (property, investments, savings, pensions)
- Debts and liabilities
- Income streams and business interests
- Potential inheritances
Transparency is non-negotiable — it’s the foundation upon which your PNA’s credibility stands.
4. The Lone Wolf Error: Lack of Independent Legal Advice
Even the most carefully worded agreement will falter if one or both parties did not receive independent legal advice (ILA) before signing.
The Mistake: Relying on one solicitor to act for both parties, or worse, having one party proceed without any legal representation.
Courts view a lack of ILA as a sign that the disadvantaged party may not have understood the consequences of the agreement or felt pressured into signing.
The Takeaway:
Both parties should instruct separate, experienced family law solicitors.
An effective solicitor does more than draft a document, they safeguard fairness, explain alternatives, and ensure each party’s rights are fully understood.
How to Future-Proof Your Prenup: A Solicitor’s Blueprint
A watertight PNA isn’t just about compliance, it’s about strategy. It must anticipate judicial scrutiny, reflect fairness, and evolve with life’s inevitable changes.
| Best Practice | Strategic Advantage |
| Start Early | Engage solicitors at least 6 months before the wedding; sign at least 28 days prior. |
| Full Transparency | Exchange complete, documented financial disclosure with supporting evidence. |
| Tailored Drafting | Avoid templates; your agreement should reflect your unique financial and personal dynamics. |
| Include a Review Clause | Schedule reviews every five years or upon major life events (children, inheritance, relocation). |
| Pass the Needs Test | Ensure that neither party will be left in real financial need, even if circumstances change. |
Real-Case Takeaways: Lessons from the Courts
| Case | Principle Reinforced | Key Lesson |
| Radmacher v Granatino (2010) | Courts will uphold PNAs that are freely entered and fair. | Fairness at the time of divorce is as important as fairness at signing. |
| Helliwell v Entwistle (2025) | Timing and disclosure are critical. | Sign early and be completely transparent. Last-minute agreements invite judicial scepticism. |
Your Next Step: Partner with a Solicitor Who Anticipates the Court
A prenuptial agreement is not just a legal document, it’s a test of foresight, fairness, and craftsmanship.
My approach is simple yet strategic: I draft every PNA as though it will one day face a judge. I anticipate the scrutiny, build in the fairness, and ensure the timing, advice, and disclosure are beyond reproach.
If your goal is to protect your assets, preserve clarity, and secure peace of mind, your first step is to engage counsel who understands both the letter of the law and the mindset of the court.
Your future deserves a PNA that endures, not one that collapses when it matters most.
Frequently Asked Questions (FAQs)
Not automatically. The courts retain ultimate discretion. However, following Radmacher v Granatino, a properly drafted PNA that is fair, entered into freely, and supported by full disclosure will be given decisive weight.
Ideally at least six months before your wedding, but never later than 28 days before. Signing too close to the date can lead the court to presume undue pressure.
If the circumstances at divorce differ dramatically, for instance, due to children, loss of income, or inheritance, a court may find the PNA unfair. That’s why review clauses are vital to keep it current.
It means complete transparency about your finances, every asset, liability, income source, and expected inheritance, supported by documents such as bank statements and valuations.
No. A PNA cannot override the court’s duty to prioritise the welfare of children. Child-related matters are always decided by the court, irrespective of what the agreement states.
Final Thought
In family law, the finest protection lies not in the promise of a contract but in the precision of its creation. A prenuptial agreement drafted with foresight, fairness, and strategic care is your most reliable shield and that begins with the right solicitor by your side.
