When couples decide to tie the knot, a prenuptial agreement (prenup) often brings peace of mind, clarity, and financial transparency. Far from being “unromantic,” a well-crafted prenup can actually strengthen a relationship by encouraging honest discussions about finances and expectations.

However, in England and Wales, a prenup isn’t automatically legally binding. Courts give them significant weight, but only if certain legal principles and procedural safeguards are followed. The problem? Many couples often unintentionally make errors that later render their agreements unenforceable.
Below, we unpack the most common mistakes that make prenuptial agreements invalid under English law, focusing on often-overlooked issues like timing, legal advice, and emotional pressure.

1- Signing Too Close to the Wedding

Timing is everything, especially when it comes to prenups.

One of the biggest pitfalls is signing the agreement at the eleventh hour, perhaps a week or even days before the wedding. English courts view such timing as a potential sign of pressure or duress, which undermines the fairness of the agreement.

Best practice: Both parties should sign the prenup at least 28 days before the wedding. This gives each person time to review, reflect, and, crucially, obtain independent legal advice without feeling rushed or coerced.

2- Lack of Independent Legal Advice

A prenup must be entered into freely and with a full understanding of its implications. If one party did not receive independent legal advice, the court may determine that they didn’t fully understand what they were signing.

This is especially critical if the agreement heavily favours one partner. The absence of proper advice can make it look like one party was taken advantage of.

Best practice: Each party should instruct their own solicitor, not the same one to ensure fairness and transparency. Their solicitors should also confirm in writing that independent legal advice was provided.

3- Failure to Disclose All Assets and Liabilities

Transparency is the foundation of any valid prenuptial agreement. If one partner hides assets or fails to disclose debts, the entire agreement may be viewed as unfair.

English courts expect full and frank financial disclosure from both sides. Omissions, whether intentional or accidental, can cause the court to disregard the prenup entirely.

Best practice:

Prepare detailed financial disclosure statements that include property, investments, savings, pensions, and debts. Both parties should review and acknowledge this information in writing.

4- Emotional Pressure or Duress

Even if the timing seems reasonable, emotional pressure can make a prenup unenforceable. This includes situations where one partner feels they must sign to avoid conflict or to prevent the wedding from being called off.

Courts look closely at the circumstances surrounding the signing—was it truly voluntary, or was there subtle coercion at play?

Best practice:

The agreement should be discussed early in the engagement, ideally months before the wedding. Both parties should have space and time to negotiate terms without emotional tension or external influence.

5- Unfair or Unrealistic Terms

English courts prioritise fairness. Even if both parties agree to certain terms, the court won’t enforce an agreement that leaves one partner in serious financial hardship or disregards the welfare of children.

If the prenup feels one-sided, one party walks away with everything while the other is left with nothing, the court is likely to intervene.

Best practice: Ensure that the agreement reflects fair and realistic outcomes, particularly regarding housing ad income. A prenup that protects both parties’ interests is far more likely to hold up in court.

6- Not Updating the Agreement Over Time

Life changes, so should your prenup. Major events like acquiring a new property or changes in income can make an old agreement outdated and unfair.

Best practice:

Review your prenup every few years or after significant life events. Updating it helps maintain fairness and strengthens its enforceability.

7- Poor Drafting or DIY Agreements

Online templates and DIY prenups may seem convenient, but they often fail to meet the formal standards recognised by English courts. Ambiguous wording, missing clauses, or a lack of procedural detail can easily render such agreements invalid.

Best practice:

Work with an experienced **family law solicitor** who understands the nuances of English law and can ensure that the document meets both legal and practical requirements.

Final Thoughts

A prenuptial agreement can offer clarity and peace of mind, but only when handled correctly. The courts in England and Wales respect these agreements, but only if they’re fair, transparent, and properly executed.

If you want a prenuptial agreement that’s flawless and free from costly mistakes, we recommend using Wenup for expert guidance and support.

Avoiding these common mistakes, especially around timing, legal advice, and emotional pressure, can make the difference between a strong, enforceable agreement and one that falls apart when it matters most.

If you’re considering a prenup, seek early legal guidance to ensure your agreement stands on solid ground. It’s not just about protecting assets, t’s about protecting trust, transparency, and future harmony.

FAQs About Prenuptial Agreements Under English Law