Illinois Prenuptial Agreements Info   

Generally speaking, the definition of a prenuptial, premarital, antenuptial agreement (yes, those are three names for the same thing) is a contract drafted between two soon-to-be spouses that is not effective until marriage. More specifically, a Prenuptial Agreement  is again, a legal contract. Generally speaking, a prenup is referred to as a “premarital” agreement in Illinois, although the definition of a prenuptial, premarital and antenuptial agreement are all terms for the same thing.

Illinois Prenuptial Agreements

According to the Illinois Uniform Premarital Agreement Act, effective and adopted by the state of Illinois in 1990, “Premarital agreement” refers to an agreement between prospective spouses made in contemplation of marriage, and is to be effective upon marriage. A premarital agreement in Illinois allows couples to contract with respect to the rights and obligations of property, the right to sell or control property, the ability to choose how they will dispose of property upon separation, dissolution or death, the modification or elimination of spousal support, the ownership rights in a life insurance policy, freedom to choose what law will govern the agreement, as well as other rights as listed in the Illinois Premarital Agreement statute, which you can read here. However, it is important to note that the rights of a child or child support cannot be affected by a premarital agreement in Illinois.

How Common are Prenups

The Basics of Illinois Prenups


What you may include in an Illinois Prenup  

  • Put it in writing! Your prenup has to be a written contract – you can’t just think it into existence. Make it a formal contract.
  • The terms included in your premarital agreement must be lawful
  • Your Illinois premarital agreement must be signed by both parties (HelloPrenup recommends initials at the bottom of each page!)
  • Your agreement must be signed voluntarily (without duress, intimidation, deceit, etc.)
  • Signatures should always be notarized (this is more of a “best practices” than a statutory requirement)
  • Fair and reasonable disclosure of assets and debt / financial obligations – that is right, this means disclosing *all* of your finances.
  • Representation by an attorney adds an extra layer of protection and is recommended!

What you can exclude from your Illinois Prenup  

  • Dictating what child custody or support should look like
  • Incentive to commit illegal acts
  • Unfair, unjust, or deceptive terms

Premarital Agreements in Illinois

In Illinois, prenuptial agreements must be written and signed freely by both parties. Prenuptial agreements in Illinois can include clauses describing how assets will be divided if the relationship ends in divorce.
No one may compel either side to sign a prenup – parties must enter into the prenup voluntarily and without duress. In addition, financial disclosure is imperative. In Illinois, parties to a premarital agreement must provide fair and reasonable financial disclosure of all assets and financial obligations. Neither party is permitted to conceal property or assets and will risk invalidation of their prenuptial agreement if they do!

Spousal Support and Illinois Prenups

According to Section 7(b) of the Illinois Uniform Premarital Agreement Act, if a prenuptial agreement provision modifies or eliminates spousal support and that modification or elimination causes one party to the prenuptial agreement undue hardship due to circumstances not reasonably foreseeable at the time of the prenuptial agreement’s execution, a court, notwithstanding the terms of the prenuptial agreement, may modify or eliminate spousal support. 

Invalid Prenup Provisions

A prenuptial agreement in Illinois can be declared invalid and unenforceable if proper financial disclosures are not made, or assets and financial obligations are hidden. For example, if one partner was dishonest in reporting assets because he said he had only $100,000 in an account when really he had $1,000,000, the agreement could be invalidated by a court.

A premarital agreement may be unenforceable under Illinois state law if the court finds that the agreement is “unconscionable.” One example of an unconscionable provision would be one that stipulates to custody or support of a child.

Financial Disclosure in a Prenup

How Maintenance Works

Add-on Illinois notarization available now:

Get your prenup notarized online with our exclusive partnership with Proof (formerly

Include IL notarization with your prenuptial agreement for just $50:

Now you can create your prenuptial agreement, collaborate on terms with your partner & optional attorneys, then notarize your prenup—all from your couch. The only thing we can’t do? Get married for you.

If you purchase Attorney Representation with your prenup, Notarization is included.

  • Finalize your prenup with HelloPrenup
  • Connect with Proof (formerly
  • Virtually connect with an online prenup notary
  • E-Sign your prenup with notary
  • Download & save your notarized document
  • Store your notarized prenup securely within your HelloPrenup account

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