Prenuptial Agreement: Key Considerations for Couples in Illinois

Discussing a prenuptial agreement in the throws of preparing for a life with your fiance is not an easy task. But it is one of the most thoughtful steps a couple can take before marriage. A “prenup” allows the spouses to clearly discuss their expectations from the marriage, reduces confusion, and helps protect both partners if the marriage ends through separation, divorce, or death. In Illinois, these agreements are governed by laws that shape what makes a valid and enforceable contract.

Below is a practical guide to help you understand the most important considerations when entering into a prenuptial agreement in Illinois.

Prenuptial Agreement Basics in Illinois

A prenuptial agreement, also called a premarital agreement or antenuptial agreement, is a written contract a couple signs before marriage to outline how property, assets, debts, and support will be handled during the marriage and in the event of divorce or death.

Illinois follows the Uniform Premarital Agreement Act, a statute that most states have adopted some version version of, and which provides clear rules regarding what a prenup can and cannot include and what actions are required to make it enforceable.

A prenuptial agreement helps couples establish clear expectations and a sense of mutual protection from the start of the marriage.

Separate Property and Marital Property in Illinois

Illinois is not a community property state. It follows an equitable distribution approach to division of property in a divorce, which means property is not automatically divided equally between the spouses. Instead, the court looks at various vague and fairly subjective factors when determining what is fair for each spouse.

A prenuptial agreement defines both separate property, which often includes premarital assets, family gifts, or an inheritance, and marital property, such as wealth and assets acquired during the marriage. A prenuptial agreement often delineates clear rules for classifying how a business would be addressed in a divorce, which is among the thornier issues that courts face in divorce proceedings.

A clear prenuptial agreement aids both partners’ understanding of what property will remain protected if the marriage ends or in the event of divorce or death, and what each spouse will receive.

Discussing Income, Debts, and Financial Responsibilities

In Illinois, a prenuptial agreement may outline how couples classify income earned during the marriage, division of expenses, savings and retirement accounts, premarital and marital debts, and future financial planning decisions. Talking through these topics before the wedding helps avoid misunderstandings later.

Business Ownership and Future Growth

If one spouse owns or plans to own a business, the prenuptial agreement can address ownership stakes, future appreciation, intellectual property, business income, and the interests of employees or business partners. Without a prenup, a business can be treated as at least partly marital property even if it was formed before the marriage, which can create complications during a divorce. A detailed agreement allows both partners to feel grounded and protected.

Spousal Support and Alimony in Illinois

Under the Illinois Uniform Premarital Agreement Act, a prenuptial agreement can address and modify spousal rights to maintenance (also known as alimony or spousal support). Illinois courts may choose not to enforce entirely any provision that would leave one spouse unable to meet basic living needs.

However, a prenuptial agreement cannot restrict, modify, or waive child support, nor can it modify rights to “custody” or parenting time with potential children of the marriage.

Because these subjects involve significant rights and responsibilities, it is important for each partner to receive independent legal advice from separate lawyers. While not required by law, doing so ensures the prenuptial agreement remains a legally binding and fair contract that reflects Illinois state law.

Protecting Children From a Previous Marriage

Couples in Illinois often use a prenuptial agreement to clarify how property will pass to children from previous marriages since a spouse may otherwise be entitled to receive assets at death even if the spouse intended that the assets would pass to his or her children. A prenup can work alongside estate planning tools to protect inheritances, family businesses, or other assets meant for children. This is especially important when one spouse has significant premarital assets, family property, or ongoing obligations from a previous marriage.

How Illinois Courts Decide If a Prenup Is Enforceable

Not every agreement is enforceable. A valid prenuptial contract must comply with Illinois law and the requirements of the Uniform Premarital Agreement Act. When reviewing a prenup, Illinois courts generally consider whether the agreement was entered into prior to the wedding, both parties signed voluntarily and without duress, each party provided full and honest financial disclosure, the terms were not grossly unfair if there was insufficient financial disclosure, and the agreement does not violate Illinois law or public policy.

A prenuptial agreement may be considered unenforceable if one party was unduly pressured to sign, or if important financial information was withheld, and the terms were so one-sided that enforcing them would be fundamentally unfair.

Signing and Notarizing the Agreement in Illinois

To help ensure the prenup remains valid and enforceable, Illinois attorneys recommend couples sign the agreement well in advance of the wedding, provide complete and accurate financial disclosures, avoid any last minute changes or pressure, each retain attorneys, and thereafter retain signed originals with other important documents. Notarization is recommended but not legally required. Following these steps provides evidence that the spouses entered into the agreement willingly and with a clear understanding of the rights and obligations involved.

Considering a Postnuptial Agreement Later

Spouses may amend a prenuptial agreement after the wedding by written agreement. If circumstances change—such as new income levels, business sales, inherited property, or additional children—an amendment can reflect these adjustments as long as it follows Illinois state law and remains reasonably fair.

How We Can Help

If you are considering a prenuptial agreement or want guidance on the full process of preparing for marriage, asset protection, and long-term financial planning, we are here to support you with clarity and compassion. Schedule a Consultation.