Illinois Prenuptial Agreement Overview
Illinois has adopted the Uniform Premarital Agreement Act, codified at 750 ILCS 10, the Illinois Uniform Premarital Agreement Act. Illinois follows the standard UPAA framework with some important judicial interpretations that have shaped how prenups are evaluated in the state. The agreement must be in writing, signed by both parties, and becomes effective upon marriage.
Illinois is an equitable distribution state that uses a two-step process in divorce: first, classifying property as marital or non-marital, and second, dividing the marital property equitably. Non-marital property includes assets acquired before marriage, gifts, inheritances, and property excluded by prenuptial agreement. Illinois courts consider numerous factors when dividing marital property, including the duration of the marriage, the age and health of the parties, and each party's occupation and earning capacity.
Illinois is notable for having a strong body of case law on prenuptial agreements, largely due to the volume of prenup litigation in Cook County (Chicago). Illinois courts have addressed numerous issues including the enforceability of spousal support waivers, the adequacy of financial disclosure, and the standards for determining voluntariness. Illinois also has a pet custody statute that allows courts to consider the well-being of companion animals, making pet provisions in Illinois prenups particularly meaningful.
Yes (UPAA)
Uniform Act adopted
No (equitable distribution)
Community property
No (but recommended)
Independent counsel
No (but recommended)
Notarization required
Illinois Prenuptial Agreement Legal Requirements
To create a valid and enforceable prenuptial agreement in Illinois, you must meet the following legal requirements established by state law:
Important: Illinois Execution Requirements
Illinois requires that prenuptial agreements be in writing and signed by both parties. The agreement becomes effective upon marriage. Both parties should provide complete financial disclosure and have adequate time to review the agreement before signing. Working with independent Illinois family law attorneys is strongly recommended for both parties.
Formal Requirements
- Written Agreement: Illinois requires the prenuptial agreement to be in writing — oral prenuptial agreements are not enforceable
- Both Parties Must Sign: The agreement must be signed by both prospective spouses to be valid
- Voluntary Execution: Both parties must sign voluntarily without duress, coercion, or undue influence
- Full Financial Disclosure: Both parties must provide complete and accurate disclosure of all assets, debts, income, and financial obligations
- Not Unconscionable: The agreement must not be so one-sided as to be unconscionable under Illinois law
What Can Be Addressed
- Rights and obligations in property owned by either or both parties
- Disposition of property upon separation, divorce, or death
- Spousal support (alimony) terms, modifications, or waivers
- Life insurance, estate planning, and inheritance provisions
- Any other matter not in violation of Illinois public policy or criminal law
Illinois Prenup Enforceability Rules
Illinois follows the UPAA framework with important judicial additions. The Illinois Supreme Court in In re Marriage of Bonds has established that courts should examine the totality of circumstances when evaluating voluntariness, including the time between presentation and signing, whether both parties had counsel, and the bargaining positions of the parties. Illinois courts evaluate unconscionability at the time of execution, and an agreement is not unconscionable simply because it favors one party — it must be so one-sided that it shocks the conscience.
Spousal Support Waiver
Permitted — Illinois courts allow spousal support waivers in prenuptial agreements, subject to unconscionability review
Sunset Clause Recognition
Recognized — Illinois courts will enforce clearly written sunset clauses that were voluntarily agreed upon by both parties
Unconscionability Standard
Evaluated at the time of execution — Illinois courts examine whether the agreement was fundamentally unfair when signed, considering the adequacy of disclosure and the bargaining positions of the parties
Illinois Prenuptial Agreement Costs
The cost of creating a prenuptial agreement in Illinois depends on the complexity of your financial situation and whether you hire attorneys. Here is a breakdown of typical costs:
| Fee / Cost | Amount |
|---|---|
| Attorney Fees (per party) | $2,500 - $10,000 |
| Notarization Fee | $5 - $10 |
| Court Filing Fee | N/A (not filed with court) |
| Online Template Service | $0 - $500 |
| Financial Advisor Consultation | $200 - $500 per hour |
| Business Valuation (if needed) | $3,000 - $15,000+ |
Sample Illinois Prenuptial Agreement
Below is a preview of our Illinois-specific prenuptial agreement template. Your customized document will include all provisions required for enforceability under Illinois law.
STATE OF ILLINOIS
PRENUPTIAL AGREEMENT
Premarital Agreement Under Illinois Law
PARTY 1:
Name: [Full Legal Name]
Address: [Illinois Address]
Attorney: [Attorney Name]
PARTY 2:
Name: [Full Legal Name]
Address: [Illinois Address]
Attorney: [Attorney Name]
AGREEMENT TERMS
Planned Wedding Date: [Date]
Separate Property Schedules: [Attached as Exhibits A & B]
Spousal Support Terms: [As Defined in Article III]
Governing Law: State of Illinois
Illinois Prenuptial Agreement FAQ
Answers to common questions about prenuptial agreements in Illinois, including enforceability, legal requirements, and state-specific rules.
Official Illinois Resources
Use these official resources for additional information about Illinois family law, prenuptial agreement requirements, and finding a qualified attorney.
Illinois State Bar Association
Find a family law attorney, legal resources
Illinois Compiled Statutes 750 ILCS 10 — Premarital Agreement Act
Official state statutes governing prenuptial agreements
Uniform Law Commission — UPAA/UPMAA
Official text of the Uniform Premarital Agreement Act
American Academy of Matrimonial Lawyers
Find a certified family law specialist in Illinois
Related Illinois Documents
Depending on your situation, you may need additional family law documents to complement your Illinois prenuptial agreement.
Illinois Postnuptial Agreement
Financial agreement for couples already married
Illinois Divorce Forms
State-specific divorce petition and filing documents
Illinois Separation Agreement
Divide assets and debts during legal separation
Illinois Estate Planning
Wills, trusts, and estate documents to coordinate with your prenup
Create Your Illinois Prenuptial Agreement
Answer a few questions and download your Illinois-compliant prenuptial agreement in minutes. Includes financial schedules, enforceability provisions, and notary acknowledgment.
No account required. Free to create and preview.