Prenups vs. Postnups: What's the Difference and Which One Should You Get?

Published on: 19 Mar 2025

Marriage is more than a romantic commitment—it’s also a legal and financial partnership. As couples plan their future together, many consider signing an agreement to define financial rights and responsibilities. This leads to an important question: Should we get a prenuptial agreement (prenup) or a postnuptial agreement (postnup)?

Both agreements serve similar purposes, but the key difference lies in timing—prenups are signed before marriage, while postnups are signed after the wedding. While prenups are more common, postnups are growing in popularity, particularly for couples who didn’t get a prenup before marriage but later realized they wanted one.

So, how do these agreements work, and which one is right for you? This guide breaks down the differences, benefits, and key considerations of prenups and postnups to help you make an informed decision for your marriage.

1. What Is a Prenuptial Agreement (Prenup)?

A prenuptial agreement (prenup) is a legally binding contract created before marriage that outlines how assets, debts, and financial responsibilities will be handled in the event of divorce or separation.

Key Features of a Prenup

Signed before marriage.
Covers pre-marital assets, debts, and financial expectations.
Can define spousal support (alimony) terms in case of divorce.
Protects family inheritances, businesses, and future earnings.
Helps avoid court disputes by setting financial expectations in advance.

Why Do People Get a Prenup?

Couples sign prenups for a variety of reasons, including:

Protecting assets – Ensuring that property owned before marriage remains separate.
Clarifying debt responsibility – Preventing one spouse from being liable for the other’s pre-marital debts.
Safeguarding a business – Keeping a business from being divided or sold in a divorce.
Encouraging financial transparency – Discussing finances openly before marriage.
Simplifying divorce – Avoiding expensive legal battles by pre-determining financial agreements.

Prenups allow couples to set clear financial expectations before tying the knot, reducing uncertainty and potential disputes.

2. What Is a Postnuptial Agreement (Postnup)?

A postnuptial agreement (postnup) is similar to a prenup but is signed after the couple is already married. While it serves the same purpose—outlining financial rights and responsibilities—it applies to existing marital assets rather than just pre-marital property.

Key Features of a Postnup

Signed after marriage.
Can address financial changes that occur during the marriage.
Covers asset division, debt responsibility, inheritance, and spousal support.
Often used when one spouse starts a business, inherits wealth, or financial circumstances change.
Can be useful for couples wanting to redefine financial terms later in the marriage.

Why Do People Get a Postnup?

A postnup can be beneficial for many reasons, such as:

Managing financial changes – If one spouse receives a large inheritance or starts a successful business, they may want to protect those assets.
Clarifying debt responsibility – If one partner accumulates significant debt after marriage, a postnup can specify who is responsible for repayment.
Addressing marital concerns – Couples experiencing financial or trust issues may use a postnup to define fair terms and rebuild confidence.
Making up for a missed prenup – Some couples realize after marriage that they wish they had signed a prenup and use a postnup to create similar protections.

A postnup offers financial flexibility for couples who didn’t sign a prenup but later recognize the value of legal clarity in their marriage.

3. The Key Differences Between Prenups and Postnups

While both prenups and postnups serve the same purpose, they differ in timing, enforceability, and the assets they protect.

A prenup is signed before marriage and primarily protects pre-marital assets, future earnings, and financial rights. It is often easier to enforce in court because both parties are entering the marriage voluntarily and without existing marital financial obligations.

A postnup, on the other hand, is signed after marriage and usually addresses assets acquired during the marriage. Since couples have a fiduciary duty to each other once married, courts may scrutinize postnups more closely to ensure they are fair to both spouses.

Despite these differences, both agreements allow couples to customize financial arrangements and protect their financial future.

4. Which One Should You Get?

You Should Get a Prenup If:

You aren’t married yet but want to establish financial expectations.
You own significant assets (business, real estate, investments) that you want to protect.
You or your partner have debt that you don’t want to become shared.
You want to clarify financial rights in case of divorce before legal marital obligations take effect.

Prenups are ideal for couples who want to set financial terms before marriage, avoiding uncertainty down the road.

You Should Get a Postnup If:

You are already married and want to protect new assets or financial changes.
One spouse receives an inheritance, starts a business, or gains significant wealth.
You didn’t sign a prenup but now realize you want financial security.
Your relationship has experienced financial or trust issues, and a postnup may help redefine expectations.

Postnups offer couples financial flexibility later in the marriage, allowing them to protect assets they may not have considered earlier.

5. Legal Considerations for Prenups and Postnups

For either agreement to hold up in court, it must meet legal requirements:

It must be in writing – Verbal agreements are not legally binding.
It must be signed voluntarily – No coercion, pressure, or last-minute agreements before a wedding.
Both parties must fully disclose finances – Hiding assets or debts can invalidate the agreement.
The terms must be fair and reasonable – Courts may reject agreements that are extremely one-sided.

A prenup is typically easier to enforce because both spouses enter it before marriage, whereas postnups face stricter legal scrutiny since couples already share financial responsibilities.

6. Final Thoughts: Prenup or Postnup—Which One Is Right for You?

Both prenuptial and postnuptial agreements offer couples financial security and peace of mind. If you’re engaged, a prenup is the best way to set financial expectations before marriage. If you’re already married, a postnup can help adjust financial terms as circumstances evolve.

Regardless of which agreement you choose, having a clear, legally binding financial plan can strengthen your marriage by promoting honesty, trust, and fairness.

Need a Prenup? Start with prenups.ai

If you're planning to get married and want to protect your assets, define financial expectations, and simplify legal processes, prenups.ai makes it easy to create a legally sound prenup online.

Legally compliant and state-specific
Easy and affordable
Fully customizable for your financial situation

Start your prenup today with prenups.ai and build a financially secure future together.

Share Blog