Prenuptial & Postnuptial Agreements: What They Should Cover
When most people hear the word “prenup,” they think of celebrities, billionaires, or high-profile divorces splashed across the news. But in reality, prenuptial agreements (prenups) are not just for the ultra-wealthy. In Illinois, they are practical planning tools that couples of all income levels can use to clarify expectations, protect property, and reduce uncertainty if the marriage ends in divorce. Similarly, postnuptial agreements (postnups), which are signed after marriage, serve many of the same functions with some unique considerations. If you would like to discuss pre- or postnuptial agreements, or other family law matters, our Troy, MI family lawyer is available to talk.
Rather than being a sign of mistrust, these agreements can strengthen relationships by creating transparency and reducing future conflict. Here’s what Illinois couples need to know about what prenups and postnups can—and cannot—cover.
Common Myths & Misconceptions
Despite their growing popularity, prenups are often misunderstood. Let’s clear up a few common myths:
“Prenups mean you don’t trust your partner.”
This is one of the most pervasive misconceptions. In reality, prenups are not about anticipating divorce but about thoughtful planning. Just as couples purchase life insurance or draft an estate plan, a prenup is another way to protect each other and their families. Many couples in Illinois view prenups as a roadmap that provides clarity, fairness, and peace of mind.
“Prenups are only for celebrities or the wealthy.”
While prenups are certainly common among high-net-worth individuals, they are equally valuable for couples with modest assets. For example, a prenup can protect one spouse from liability for the other’s debt, preserve a family business, or establish how savings will be handled. With the rising trend of people marrying later in life—often after building careers, accumulating property, or accruing debt—prenups make sense for more couples than ever before.
What Prenups Can Cover
Illinois follows the Illinois Uniform Premarital Agreement Act (750 ILCS 10/1 et seq.), which governs what prenuptial agreements may include. Properly drafted, a prenup can cover a wide range of financial matters.
1. Property Division
Without a prenup, Illinois divorce law requires courts to equitably divide marital property. A prenup allows couples to decide in advance how property will be classified and divided. For instance, they can agree that certain assets—such as a home owned prior to marriage—will remain separate, or that future savings will be split in a specific way.
2. Debt Protection
Debt is an increasingly important issue for couples. A prenup can shield one spouse from being responsible for the other’s loans, credit card balances, or business debt. By clarifying responsibility, couples avoid surprises and financial disputes later.
3. Business Ownership & Intellectual Property
If one or both spouses owns a business, a prenup can establish how ownership and growth will be handled during the marriage. This prevents situations where a divorce disrupts company operations or forces a sale. Likewise, prenups can protect intellectual property—such as patents, creative works, or professional goodwill—ensuring that one spouse’s professional efforts are safeguarded.
4. Estate Planning Coordination
Prenups can also clarify how assets will pass upon death, aligning with estate plans. For example, they can make sure that children from a prior marriage inherit specific assets, while also providing for a current spouse.
What Prenups Cannot Do
Although prenups are flexible, Illinois law places important limitations on them.
Parental Responsibilities & Support Waivers
Illinois courts prioritize the best interests of children, which cannot be predetermined in a prenuptial agreement. A prenup cannot dictate future parental responsibilities arrangements or waive child support obligations. Any such provisions are unenforceable.
Unconscionable Terms
Even if both parties sign, a prenup that is grossly unfair or leaves one spouse without reasonable support could be struck down. Illinois courts will not enforce an agreement that violates public policy or equity.
Postnuptial Agreements
While prenups are signed before marriage, postnuptial agreements are executed after the wedding. Many Illinois couples pursue postnups for practical reasons:
1. Why Couples Sign Them After Marriage
- Changed financial circumstances: A spouse inherits property, sells a business, or receives a large bonus.
- Second marriages: Couples may want to clarify estate planning for children from prior marriages.
- Relationship rebuilding: Some couples use postnups during reconciliation after marital difficulties, establishing financial clarity to reduce stress.
2. Enforceability Differences
In Illinois, postnuptial agreements are generally enforceable under contract law. However, because they are made after marriage, courts scrutinize them more closely for fairness and voluntariness. Spouses already owe fiduciary duties to each other, so full disclosure and equitable terms are essential. A poorly drafted postnup risks being invalidated if it appears coercive or one-sided.
Practical Drafting Tips
Whether you’re considering a prenup or postnup in Illinois, several best practices increase enforceability and fairness:
Full Financial Disclosure
Each party must disclose assets, income, and liabilities in detail. Concealing information can invalidate the agreement later.
Independent Counsel
Each spouse should have their own attorney. This makes certain both parties fully understand the terms and reduces claims of undue influence.
Fairness Standards
While prenups can favor one party to an extent, they cannot be unconscionable. Courts will examine whether the agreement leaves one spouse destitute or violates public policy.
Timing Matters
For prenups, the agreement should be negotiated well before the wedding. Presenting a prenup right before the ceremony risks a finding of duress. For postnups, agreements should be signed at a time of stability, not during heightened marital conflict.
Case Example Of Prenup Success
Consider a hypothetical Illinois couple: Sarah, a physician, and Mark, an entrepreneur. Before marrying, Sarah owned a medical practice and significant retirement accounts, while Mark had a growing startup but also student debt.
They signed a prenup clarifying that:
- Sarah’s practice and retirement accounts would remain her separate property.
- Mark’s startup would remain his separate property, but they agreed to share profits generated during the marriage in a specific ratio.
- Each spouse would be responsible for debts in their own name.
- They established terms for spousal support in the event of divorce.
Ten years later, they divorced amicably. Because expectations were clearly outlined, neither party engaged in costly litigation over the business, debts, or savings. The prenup allowed them to move forward with financial clarity, avoiding years of courtroom battles.
Agreements Strengthen Relationships
In Illinois, prenuptial and postnuptial agreements are not just safety nets for the wealthy—they are planning tools that provide clarity, fairness, and peace of mind for couples at all income levels. By addressing property division, debt protection, and business ownership in advance, couples reduce uncertainty and protect their future.
While these agreements cannot dictate parental responsibilities or waive child support, they can create a foundation of transparency and trust. Whether signed before or after the wedding, a carefully drafted agreement—with full disclosure, independent legal counsel, and fair terms—can prevent disputes and even strengthen marriages.
Merel Family Law opened our doors in 2009 and since then we have successfully helped 5,500+ clients with a wide range of family law needs. We help clients navigate prenups and postnups with a focus on protecting both their legal and emotional well-being. If you are considering one of these agreements, our experienced team can make certain it is tailored to your unique circumstances and enforceable under Illinois law. Reach out to us any time of the day or night, every day of the year.
