Postnuptial Agreement Calculator
Analyze the financial case for a postnuptial agreement. Unlike a prenup (signed before marriage), a postnup is signed during marriage and is increasingly common after infidelity, business growth, or inheritance. See your protection value, enforceability score, and ROI.
| Scenario | Potential Loss |
|---|---|
| Without postnup | $350,000 |
| With postnup | $250,000 |
| Protection value | $350,000 |
Understanding Postnuptial Agreements
A postnuptial agreement (postnup) is a legal contract between spouses entered into after marriage that defines how assets, debts, and financial matters will be handled in the event of divorce or death. While prenuptial agreements are signed before marriage, postnups address the same issues but are executed during an existing marriage. Postnups have grown significantly in popularity over the past two decades, driven by changing attitudes toward marriage, increased business ownership, and the desire to formalize financial arrangements after significant life events.
Common reasons couples pursue postnups include: after infidelity (as part of a reconciliation agreement), when one spouse starts or grows a business, upon receiving a significant inheritance, to protect against a spouse's growing debt, for estate planning purposes (especially in blended families), and as part of a structured reconciliation after separation. In each case, the postnup provides clarity and protection that might not exist under default state law.
How Postnups Differ from Prenups
While postnups and prenups cover similar topics, there are important legal differences. Postnups face greater judicial scrutiny because spouses owe fiduciary duties to each other that do not exist between engaged couples. Courts are more likely to examine whether both parties had adequate information, whether the agreement is fair, and whether there was any undue influence or coercion. Because of this heightened scrutiny, it is even more critical that each party has independent legal counsel when executing a postnup.
Not all states treat postnups equally. While most states recognize postnuptial agreements, some states (like Ohio) historically have not enforced them, and others apply stricter standards than they would to prenups. The enforceability also depends on factors like whether both parties had independent attorneys, whether there was full financial disclosure, and whether the terms are considered "unconscionable" (grossly unfair to one party). This calculator includes a state-by-state enforceability assessment.
When a Postnup Makes Financial Sense
The ROI of a postnup becomes compelling when significant separate assets or business interests could be claimed as marital property without an agreement. For business owners, the appreciation of a business during marriage is often considered marital property subject to division, even if one spouse built the business entirely with their own effort. A postnup can define business interests as separate property, potentially protecting hundreds of thousands or millions of dollars.
Similarly, inheritances can lose their separate property status through commingling (mixing inherited funds with marital accounts) or by using inherited assets for marital purposes. A postnup can preserve the separate character of inherited assets regardless of how they are managed. The typical cost of a postnup ($5,000-$20,000 for two attorneys) is modest compared to the assets at stake for most couples pursuing this option.
Frequently Asked Questions
Can a postnup be signed after infidelity?
Yes, this is one of the most common scenarios. "Reconciliation postnups" typically provide financial consequences if the unfaithful spouse repeats the behavior, such as a more favorable property division or alimony arrangement for the injured spouse. However, these agreements face extra scrutiny because courts may question whether the injured spouse was under emotional duress. Having both parties represented by independent attorneys and allowing adequate time for review significantly improves enforceability.
Will my spouse be offended if I suggest a postnup?
Approaching the topic requires sensitivity. Frame it as financial planning, not divorce planning. Many couples successfully negotiate postnups by focusing on mutual benefits such as estate planning, business protection, or clarifying financial expectations. Starting the conversation with a financial planner present can make it feel more like responsible planning and less like an accusation. Some therapists also specialize in helping couples navigate these discussions.
Can a postnup address child custody or support?
No. Like prenups, postnuptial agreements cannot determine child custody or child support. Courts always retain jurisdiction over matters affecting children and will make custody and support decisions based on the child's best interests and state guidelines at the time of divorce, regardless of any agreement between the parents.