Yes, if done properly, Illinois courts will hold the parties to their prenuptial or premarital agreement. Prenups are the best way to protect premarital assets from becoming marital property, and to minimize litigation in the event of a divorce.

Illinois law does set out a way to invalidate a prenup (see 750 ILCS 10/7). To avoid these traps, the best practice is for each side to have a different attorney review the agreement. In addition, a prenup will likely be upheld by a judge if it meets the following criteria:

• The agreement is in writing. In my experience, judges are looking for more than just being in writing. They want to see a professionally typed document, formatted like a formal contract. I’ve even seen a judge refuse to uphold a hand written prenup, even though it was signed by both parties.

• Both parties have signed the agreement. However, the best practice is to go beyond just signing the last page. I always have my clients initial the bottom of every page and get their signatures notarized.
• Full and accurate disclosure. By law, both sides must provide each other with a disclosure of their income, property, and financial obligations. I have a comprehensive disclosure form that I have my clients complete and attach to their prenups.
• Agreement is voluntary–not signed under duress. To ensure an agreement is voluntary, it must be presented it to your fiancé/fiancée well before the wedding takes place. And the best practice is for both sides to have an attorney. Although this is not required by law, someone could try to argue that they can’t voluntarily agree to provisions that they don’t understand. My experience is that judges also prefer that each side has been represented.
• The terms are fair. The terms of the prenup cannot be unconscionable, meaning that the terms of the agreement cannot be unusually harsh or unfair to one party. Of course, it is hard to predict what a judge will find to be unconscionable, so you should consult with an attorney experienced in dealing with prenups.