Prenup Contracts 101: Legal Frameworks Explained

A prenup contract can feel like a heavy topic. Is it just for wealthy couples? Is it legally binding? Does it mean you’re planning for divorce before the marriage even begins?

Neptune exists to help you sort out all this. It is a first-of-its-kind financial concierge built for couples with complex finances and professional ambition. Starting with prenups, we guide partners through high-stakes money decisions with clarity, empathy, and strategy. 

If you're building your career, growing assets, or blending families, you've probably already learned the value of planning, and that's exactly what a prenup provides.

So, what does a prenup contract actually involve? And what makes it legally sound?

Let’s unpack the legal framework, so you can understand what goes into a prenup and whether it makes sense for your relationship.

What Is a Prenup Contract?

A prenuptial contract, or prenup, is a legally binding agreement made between two people before they tie the knot. At its most practical level, it outlines how financial matters will be handled during the marriage and if the relationship ends.

But more than that, a prenup provides a blueprint for your financial future with your partner.

Every prenup is different because every couple is different. Still, most agreements tend to address key questions like:

• What assets and debts each partner brings into the marriage, and whether those remain separate.
• How income, savings, and investments will be handled during the relationship.
• How financial responsibilities (like debts or major purchases) will be shared.
• Any financial plans involving children from previous relationships. It is essential to know that child custody cannot be addressed in a prenup.
• Guidelines for future financial decisions, such as purchasing real estate or starting a business.

Legal Requirements for a Valid Prenup

A prenup contract carries legal weight, but only if it’s drafted and executed well. While the exact requirements vary by state, most courts look for a few key aspects that ensure the agreement is fair, informed, and made in good faith.

Here’s what matters: 

1. Voluntary Agreement

Both parties must enter into the contract willingly. If there’s evidence that one person was pressured, rushed, or coerced, especially close to the wedding date, a court may decide the agreement isn’t valid.

Some states have safeguards in place. For instance, California requires a seven-day waiting period between presenting the final version and signing it, to give each person time to review and reflect without feeling pressured.

2. Full Financial Disclosure

Transparency is non-negotiable. Each partner must clearly share their financial picture, including income, assets, debts, and any material financial details. Hiding or downplaying important information can jeopardize the agreement later on.

Many prenups include a schedule of assets and liabilities as an attachment. It’s a simple, effective way to keep things clear and documented.

3. Fair and Reasonable Terms

Prenup contracts don’t need to split everything evenly, but they do need to be fair. Agreements that are heavily one-sided or leave one partner without adequate financial cover could be challenged in court.

State laws vary here:

• A prenup with uneven terms in New York may still be valid if both parties understood what they were signing and each had legal counsel.
• In North Carolina, courts may scrutinize fairness more and can set aside agreements deemed “unconscionable.”

In short, your prenup should be reasonable and reflect mutual respect for each other’s needs and contributions.

4. Proper Execution

For a prenuptial agreement to hold up legally, it needs to be documented in writing and signed by both individuals involved. While notarization isn’t always required, it’s strongly recommended to avoid future challenges.

It’s also wise for each person to have independent legal counsel. There’s no point in getting a prenup if it gets struck down by courts. One of the most common reasons for prenups to get struck down is that only one lawyer was involved.

State Laws Can Impact Enforceability

Prenups are legal in all 50 states, but how they’re enforced depends on state-specific laws. Many states follow the Uniform Premarital Agreement Act (UPAA) or its updated version, the Uniform Premarital and Marital Agreements Act (UPMAA), which provides a standard legal framework. 

Others apply their own rules. For example, while some states allow spousal support waivers, California may override them if they’re deemed unfair. 

That’s why it’s smart to work with a family law attorney to include what’s called a choice of law clause, which names the state that governs your prenup.

Do Prenups Only Apply if You Get Divorced?

The short answer is: No. Prenuptial agreements allow two people in a committed partnership to have an open conversation about finances, values, and the goals they have in mind for their future.

 As a couple, you can use a prenup agreement to:

• Clarify ownership in a new business
• Set expectations around career changes or caregiving roles
• Outline inheritance plans
• Shield one partner from liability for the other’s debts

Prenups also are there to support estate planning. While they don’t replace a will, they can work alongside one, helping reduce confusion and provide clarity in the unfortunate event of a partner’s death.

Ready to Commit? Let Neptune Help You Plan With Confidence

A prenup contract isn’t about anticipating the worst but building trust before you walk down the aisle. When you and your partner define expectations early, you build a stronger foundation for the years ahead.

At Neptune, we’re built for partnership. Whether you’re entering marriage with equal assets, income gaps, or future earning imbalances, Neptune ensures both partners receive dedicated support and legal representation.

Thinking about a prenup? Let’s make it feel less like a contract and more like a commitment, on your terms, together. Start the conversation with Neptune today.