Common Law Marriage in Illinois: Legal Requirements and Exceptions

Many couples in long-term relationships assume they might be considered married under the concept of common law marriage—especially if they live together, share finances, or introduce each other as spouses. But if you live in Illinois, the situation is clear: common law marriage is not recognized.

This article breaks down Illinois’ stance on common law marriage, explains key exceptions, and outlines what unmarried couples can do to protect their rights in 2025.

What Is Common Law Marriage?

Common law marriage is an informal type of union where two people are legally considered married without a license or ceremony, typically after living together for a certain period and presenting themselves publicly as spouses.

States that allow this practice require specific legal criteria, including mutual intent to be married, cohabitation, and public acknowledgment of the relationship as a marriage.

Does Illinois Recognize Common Law Marriage?

No. Illinois does not allow or recognize common law marriages formed within the state. This has been the law for many years. Even if you’ve been living together for decades and function as a married couple, you are not legally married in Illinois unless you go through the formal process of obtaining a marriage license and having a legal ceremony.

The Exception: Out-of-State Common Law Marriages

While Illinois does not permit new common law marriages within the state, it does recognize valid common law marriages from other states where such unions are legal.

If you and your partner entered into a common law marriage in a state like Colorado, Texas, or Iowa—and met all of that state’s requirements—Illinois will honor your marital status when you move there.

To prove your out-of-state common law marriage, you may need:

• Evidence of joint finances or property
• Testimony or affidavits confirming your public commitment
• Legal documents or statements that show intent to be married

Legal Risks for Unmarried Couples in Illinois

Without legal marriage or a recognized common law union, unmarried couples in Illinois have no automatic rights regarding:

• Property ownership and division during a breakup
• Inheritance or estate claims
• Medical decision-making rights
• Spousal benefits (health insurance, retirement plans, etc.)

This can leave long-term partners vulnerable in the event of separation, illness, or death.

Legal Alternatives for Unmarried Couples in Illinois

Couples who choose not to marry can still protect their relationship and assets through several legal tools:

1. Cohabitation Agreement

This contract outlines financial arrangements, division of property, and expectations during the relationship and after separation.

2. Power of Attorney

Gives your partner the legal authority to make financial or healthcare decisions on your behalf.

3. Will or Estate Plan

Ensures your partner inherits assets and is included in your final wishes, since unmarried partners do not automatically inherit under Illinois law.

4. Joint Ownership

List both names on property titles, bank accounts, or vehicles to establish shared legal rights and responsibilities.

Final Thoughts

If you’re in a committed, long-term relationship in Illinois but aren’t legally married, it’s essential to understand that you don’t have the same rights and protections as a married couple.

To avoid legal complications and ensure your partner is protected, consider drafting the appropriate legal documents.

For personalized advice or help with cohabitation agreements and estate planning, consult with an Illinois family law or estate planning attorney.

About The Author