Why a private financial agreement is not a prenup, and why that's a good thing

Most people who look into prenuptial agreements in the UK come away with one of two reactions: either it's too expensive (£2,000–£10,000 for a solicitor-drafted prenup), or it feels emotionally wrong, like planning for divorce before the wedding.

A private financial agreement is neither of those things. It's also not a prenup. It's something different.

What a prenup actually is

A prenuptial agreement is a specific legal instrument designed to operate within family law. In England and Wales, it carries weight in court when both parties had independent legal advice, made full financial disclosure, signed freely, and the terms meet both parties' reasonable needs (Radmacher v Granatino, 2010). It must be signed before marriage. It only covers married couples. A formal prenup costs thousands. And even then, a court retains discretion to override it.

What a private financial agreement is

A private financial agreement is a contract between two competent adults. Contract law, not family law. It doesn't require solicitors, specific timing, or marriage. It requires offer, acceptance, consideration, and absence of duress, all of which are straightforward to satisfy.

In England and Wales, the doctrine of Balfour v Balfour (1919) established a presumption that domestic arrangements are not intended to be legally binding, but this is a presumption, not a rule, and it is rebutted by explicit language, independent consideration, and the clear intention to create legal relations. A well-structured private financial agreement does all of this.

What it means in practice

Family law courts retain wide discretionary powers and can override private agreements, including prenups. So a private financial agreement is not a guarantee of enforcement in a contested court case. Neither is a prenup.

But the 90% of separations that never reach a contested court hearing? A private financial agreement is exactly what's needed. A signed, timestamped document with full financial disclosure from both sides, renewed annually, is a powerful anchor for private negotiation and mediation. It's the starting point that makes the process faster, fairer, and cheaper.

The honest comparison

Requires marriage, Prenup: yes · Nuppact: no
Requires a solicitor, Prenup: strongly recommended · Nuppact: no
Available to cohabiting couples, Prenup: no · Nuppact: yes
Cost, Prenup: £2,000–£10,000 · Nuppact: $79
Annual renewal, Prenup: no · Nuppact: optional
Overrideable by family court, Prenup: yes · Nuppact: yes (we're honest about this)
Useful in mediation, Both: yes
Useful as evidence of intent, Both: yes

You're not getting a worse version of a prenup. You're getting a different tool, one that's honest about what it is, accessible to every couple, and designed for the reality of how most separations actually work.