Make Sure Your Prenup is Enforceable

 Posted on May 13, 2026 in Prenuptial and Postnuptial Agreements

Prenuptial agreements, also known as prenups, constitute a special type of contract between prospective spouses. Prenups are different than other types of contracts, which are legal if there was a "meeting of the minds" when the contract was formed. Specifically, prenups allow both parties to take a second look at the terms of the agreement. Yet what does this mean if you are considering signing a prenup? It means that your prenup has to be fair and reasonable at the time it is executed. 

It is possible that at the time of enforcement, a court could find an agreement to be invalid, even if the parties entered the agreement with full knowledge and consulted counsel. If you are divorcing and have a prenuptial agreement in 2026, it is important to consider the circumstances under which a court may find a prenuptial agreement invalid.

For help with a marital agreement, consider working with Davi Law Group. Our DuPage County, IL divorce lawyer has over 20 years of legal experience, making him a sound choice to assist with your concerns.

Understanding the UPAA and Prenuptial Agreements in Illinois

Illinois has adopted the Uniform Premarital Agreement Act (UPAA). The UPAA establishes a set of guidelines that a court will use when deciding whether or not a prenuptial agreement is valid.

There are a few basic requirements for prenuptial agreements. The prenup must be in writing, and both spouses must sign the prenup. However, the prenuptial agreement does not need to be witnessed or signed by anyone other than the couple, and it does not have to be recorded by a court clerk.

What Are Prenups and Postnups Used for in Illinois?

A prenuptial agreement is a legal contract signed before marriage. A postnuptial agreement is similar, but spouses sign it after they are already married. In Illinois, these agreements are often used to decide how money, property, and debts will be handled if the marriage ends.

A prenup can explain what will stay separate property. This may include a home, business, retirement account, inheritance, or savings one person had before marriage. It can also explain how certain marital property will be divided. Some couples use a prenup to protect a family business, avoid debt disputes, or make financial expectations clear before problems begin.

When Is a Prenup Unenforceable in 2026?

A court might invalidate a prenuptial agreement under these circumstances:

• One spouse signed the agreement under duress.

• The terms of the agreement would make one spouse eligible for public assistance.

• The terms of the agreement are unconscionable or severely unfair/unjust.

• One spouse did not disclose the true value of his or her assets and debts.

• The spouse who did not receive the other spouse’s financial information did not waive that right.

• The spouse who did not have the other’s spouse’s financial information could not have gotten the information from another source.

Generally, courts enforce prenuptial agreements. The fact that one spouse receives more assets than the other spouse is not enough for a court to find a prenuptial agreement unenforceable. 

Can Illinois Prenups Include Terms About Child Custody and Child Support?

A prenup can address many financial issues, but it cannot decide child custody in advance. Illinois courts make decisions about children based on the child’s best interests at the time of the case. Parents cannot use a prenup to lock in a custody schedule before a child is even born or before the court knows the child’s needs.

The same is true for child support. Parents cannot agree to waive child support in a prenup. Child support belongs to the child, not just the parents. A court will want to know what support amount is proper under Illinois law when the issue comes up.

A prenup may include terms about how parents plan to handle some family costs. But those terms cannot take away the court’s power to protect a child. If a prenup includes unfair or improper child-related terms, the court may ignore those parts of the agreement.

What Do Duress and Unconscionability Mean in a Prenuptial Agreement?

For a court to find a prenup unenforceable due to duress, a spouse must be able to demonstrate that their spouse pressured him or her to the point that he or she had no choice but to sign the agreement. This must be more than one spouse saying the marriage will not take place if the prenup is not signed. Generally, duress means that one spouse applied improper pressure or influence over the other spouse such that he or she took away his or her spouse’s free will.

Generally, a court will not enforce unconscionable contract agreements, and a prenuptial agreement is not an exception to that rule. The court will invalidate a prenuptial agreement if the terms of the agreement are so unfair that it would result in catastrophic circumstances for one spouse. If the terms of the agreement are so unfair that one spouse would face extreme financial hardship while the other prospered, then it is unlikely the court will enforce the agreement.

Should I Have an Illinois Attorney Review My Prenup?

Having an attorney review a prenup is one of the best ways to protect the agreement. A lawyer can look for unclear language, missing financial details, or terms that may not hold up in court. This matters because a poorly written prenup can lead to the same disputes it was meant to prevent.

Each person should have a fair chance to review the agreement before signing. Ideally, each person should also have their own lawyer. This helps show that both people understood the agreement and had time to ask questions. Signing right before the wedding can raise questions about duress. 

Our firm can also help make sure the agreement aligns with Illinois law. A strong prenup should be clear, complete, and signed in a way that shows both people agreed freely.

Contact Our Wheaton, IL Family Law Attorneys

If you are considering a divorce and you believe your prenuptial agreement may not be enforceable, contact the DuPage County, IL premarital agreement lawyers at Davi Law Group today. We can review the terms of your prenup and help determine whether a court may find it unenforceable. Call us at 630-657-5052 to set up a free consultation.