What Should an Illinois Prenuptial Agreement Include?

 Posted on September 14, 2026 in Family Law

A prenuptial agreement, typically known as a prenup, is a written contract created by two individuals prior to their marriage. This legally binding document can set terms for how property is divided, whether alimony will be paid and how much, and other possible issues in the event of a divorce. The state of Illinois has its own laws on what can and cannot be included in a prenuptial agreement, so before you sign on the dotted line, make sure to consult with a knowledgeable DuPage County, IL family law attorney to verify its validity.

At A. Traub & Associates, we can draft or review a prenuptial agreement to make sure your interests are protected. With over 100 years of combined experience to our name, we have the legal knowledge to help you create an agreement that fits your needs and protects your interests.

What Issues Can a Prenuptial Agreement Cover in 2026?

A prenup is not a one-size-fits-all arrangement. The elements that one couple may address in their agreement might not be appropriate for another couple’s situation. However, the topics listed below are a few general ideas you may want to consider including in your agreement: 

• Asset and property division: Without a valid prenup, Illinois courts divide marital property fairly, which does not always mean equally. A prenup can state how certain property or assets will be divided if the marriage ends.
• Marital debt: Discussing the division of debt between spouses can be challenging. Addressing difficult topics like this from the get-go allows for full transparency. It is important to establish who will be responsible for paying off any outstanding credit card balances or vehicle loans if your marriage ends.
• Pets: What will happen to the family pet if you get divorced? A prenup can address who will own the pet or be responsible for its care. Illinois courts can also consider the well-being of the animal when making decisions about a companion animal (750 ILCS 5/503).
• Family heirlooms: Do you have precious family keepsakes you would like to protect? It is important to specify how you would like them to be handled or split in the event of divorce.

When drafting a prenup, you should make sure the terms are as clear as possible to avoid any confusion later. If you and your spouse later disagree about what a prenup was ‘supposed’ to cover, it can lead to a lengthy court dispute – which is counterproductive to the goal of a prenup in the first place.

What Are You Prohibited From Including in a Prenup?

A prenuptial agreement in Illinois cannot decide everything in a marriage. Courts place strict limits on what these agreements can control, especially when children are involved. A prenup cannot set final terms for child support. Child support belongs to the child, not the parents. Illinois courts always keep the right to review and adjust support based on what a child actually needs at the time. 

A prenup also cannot decide parental responsibilities, which used to be called custody. A judge looks at the child's best interests first, rather than any prior agreement between the parents. Any clause in a prenup that tries to lock in a parenting schedule or remove a parent's rights in advance will likely be thrown out. Couples can still discuss these topics honestly before marriage, but they should understand that a judge, not the prenup, will make the final call if parents cannot agree later.

Why Is Full Financial Disclosure Important for a Prenuptial Agreement?

Full financial disclosure means both spouses share complete and honest information about their income, debts, property, and assets before signing a prenup. This step protects the agreement from being challenged later. If one spouse hides money or downplays debt, the other spouse cannot make an informed decision about what he or she is agreeing to.

Illinois law allows a person to waive the right to receive more financial information, but the waiver must be voluntary, clear, and in writing. Even with a waiver, that person should have enough knowledge of the other person’s property and financial obligations. Without that basic understanding, the agreement can be easier to challenge later because one person may not have fully understood what he or she was agreeing to. Clear and complete financial information, even when a waiver is signed, gives both spouses a stronger foundation and gives the agreement a better chance of holding up if it is ever questioned.

Can a Judge Choose Not to Enforce a Prenuptial Agreement in Illinois?

Illinois judges can refuse to enforce a prenup if it does not meet certain legal standards. For example, an agreement can be challenged if one person did not sign it voluntarily. Pressure, rushed timing, or a lack of legal counsel can all raise questions about whether the agreement was signed freely.

A judge can also refuse to enforce a prenup if it was extremely unfair when it was signed and one person did not receive enough information about the other person’s finances. If one spouse hid assets or misrepresented finances, the agreement can be challenged. Even a well-written prenup is not automatically guaranteed to hold up in court. Working with a family law attorney who understands Illinois law can help reduce the risk of a prenup being challenged or dismissed later.

Can a Postnuptial Agreement Include the Same Terms as a Prenup?

A postnuptial agreement is similar to a prenup, but couples sign it after the wedding instead of before. Postnups can cover many of the same topics as prenups, including property division, spousal maintenance, and how debts will be handled if the marriage ends.

Just like a prenup, a postnup still cannot set final terms for child support or parental responsibilities. Those decisions remain with the court based on the child's needs at the time. Because postnups are signed after marriage, different legal rules can apply to them. An attorney can help make sure the agreement meets Illinois requirements.

Contact Our Wheaton, IL Family Law Attorneys

If you are considering creating a prenuptial agreement and have questions or concerns, contact a qualified DuPage County, IL prenuptial agreement lawyer from A. Traub & Associates. Our experienced legal team can provide practical legal advice regarding creating, signing, modifying, or enforcing your prenuptial agreement. Call or text us today at 630-426-0196 to schedule an appointment.