Common law marriage in Illinois has not been legally possible since June 30, 1905. No matter how long you live with a partner, share a last name, combine finances, or introduce each other as spouses, Illinois will not treat you as married without a license and a ceremony. The one meaningful exception is a common law marriage validly formed in another state that still allows them; Illinois will recognize that.
The Statute That Ended It
Section 214 of the Illinois Marriage and Dissolution of Marriage Act states plainly that common law marriages contracted in Illinois after June 30, 1905, are invalid.1Illinois General Assembly. 750 ILCS 5/ Illinois Marriage and Dissolution of Marriage Act – Section: Part II Marriage There is no threshold of years, no exception for couples who “held themselves out” as married, and no rescue by intent. Duration doesn’t matter.
A valid Illinois marriage requires three things: a marriage license from a county clerk, a ceremony performed by someone authorized under state law (a judge, clergy member, or certain public officials), and registration of the marriage certificate with the county clerk afterward.1Illinois General Assembly. 750 ILCS 5/ Illinois Marriage and Dissolution of Marriage Act – Section: Part II Marriage Skip any of those steps and you are not married in Illinois.
When Illinois Will Recognize a Common Law Marriage From Another State
You can’t form a common law marriage in Illinois, but Illinois will honor one that was validly formed somewhere else. The Full Faith and Credit Clause of the U.S. Constitution requires each state to respect the legal acts of other states.2Legal Information Institute (LII) / Cornell Law School. Article IV U.S. Constitution A couple who established a common law marriage in Colorado or another recognizing state and later moved to Illinois has access to spousal rights here as if they carried a marriage certificate.
Illinois courts will look closely at whether the originating state’s requirements were actually met. Those typically include a mutual present agreement to be married, living together, and publicly holding yourselves out as a married couple. Meeting those standards in the other state is what matters, not anything you did after arriving in Illinois.
States That Still Allow It
According to the National Conference of State Legislatures, the states that still permit new common law marriages are Colorado, Iowa, Kansas, Montana, New Hampshire (for inheritance purposes only), Oklahoma, Rhode Island, South Carolina, Texas, Utah, and the District of Columbia.3National Conference of State Legislatures. Common Law Marriage by State Each sets its own requirements, and some have age minimums or other restrictions. Several other states will still recognize a common law marriage formed before that state’s own cutoff date. If you think you may have one, the relevant law is the law of that state at the time you claim the marriage began.
Ending a Common Law Marriage
A valid common law marriage does not dissolve on its own. Moving to Illinois doesn’t end it. Separating doesn’t end it. Like any other marriage, it requires a formal divorce proceeding. Until a court enters a decree, you remain legally married and cannot remarry. Property division and support run through the courts the same way they would after any divorce, though the spouse filing may first need to prove the common law marriage existed through testimony and documentation.
What Cohabiting Couples in Illinois Actually Lose
Without a formal marriage, partners living together in Illinois are treated as legal strangers in most respects. There is no automatic right to divide property when the relationship ends, no spousal support obligation, and no inheritance if a partner dies without a will. Courts generally look at whose name is on a title, not who contributed to acquiring the asset or how long the couple shared their lives.
Cohabiting partners also have no automatic authority to make medical decisions for each other. If one partner is incapacitated, hospitals will turn to legal next of kin rather than the unmarried partner. A healthcare power of attorney is the only reliable way to give your partner that authority, and a financial power of attorney does the same job for money and property. Both documents are inexpensive and should be a priority for any unmarried couple building a life together.
Illinois intestacy law makes the inheritance gap especially sharp. If your partner dies without a will, the estate goes to the surviving spouse and descendants under statute.4Justia. Illinois Compiled Statutes Chapter 755 – Estates 755 ILCS 5/ Probate Act of 1975 Article II – Descent and Distribution An unmarried partner is not a spouse and does not appear anywhere in that hierarchy. Without a will or trust naming you, you inherit nothing, regardless of the length of the relationship.
Cohabitation Agreements Are Harder to Enforce in Illinois
In most states, unmarried couples can sign a cohabitation agreement setting out how they will handle property, finances, and support. Illinois is an outlier, and this is the single most important thing unmarried couples in the state need to understand.
The Illinois Supreme Court held in Hewitt v. Hewitt (1979) that granting property rights to unmarried cohabitants would violate the public policy behind the Marriage and Dissolution of Marriage Act. In 2016, the court reaffirmed that position in Blumenthal v. Brewer, holding that property and financial claims between unmarried partners are unenforceable when they arise from a marriage-like relationship.5Illinois Courts. Blumenthal v Brewer, 2016 IL 118781 The court declined to overrule Hewitt and said any change was up to the legislature.
In practice, an agreement that says “we’ll split everything we accumulate while living together as a couple” looks like exactly what the court rejected. Agreements with what courts call an “independent economic basis” apart from the relationship stand on firmer ground: a straightforward business or property contract between two people who happen to live together isn’t barred just because they cohabit. The safest approach is to structure any arrangement as a conventional property or business agreement with clear, independent consideration, keep it specific to individual assets rather than pooled “our” property, and have each partner represented by separate counsel. Even then, enforceability in Illinois is less certain than in most other states.
Equitable Claims Are Also Limited
The same reasoning limits unjust enrichment and constructive trust claims between unmarried partners. In many states, a partner who contributed heavily to an asset held in the other partner’s name can recover the value of those contributions. The Illinois Supreme Court held that such claims are barred when they arise from a marriage-like relationship and lack an independent economic basis.5Illinois Courts. Blumenthal v Brewer, 2016 IL 118781 If you pay for half the house but only your partner’s name is on the deed, your recourse in Illinois is very limited. Keep clear records and document ownership interests as they are created, not after a breakup.
What Unmarried Couples in Illinois Should Do Instead
Because Illinois law will not fill in the gaps for you, protecting each other requires deliberate paperwork.
A will is the baseline. It lets you name your partner as a beneficiary and specify what they receive. Without one, everything passes to blood relatives under the intestacy statute. A revocable living trust can go further, avoiding probate and allowing you to set conditions on how assets are managed over time.
Beneficiary designations do work Illinois marriage law will not. Life insurance policies, retirement accounts like 401(k)s and IRAs, and payable-on-death bank accounts transfer directly to whoever is named, outside of both wills and intestacy. If your 401(k) still lists a parent or ex from years ago, your current partner receives nothing from it no matter what your will says. Reviewing and updating designations is one of the cheapest, highest-value steps an unmarried couple can take.
Powers of attorney handle the situations that come up before death: incapacity, hospitalization, managing bills when someone can’t. Titles and deeds matter too. If you both contribute to a home, both names should be on the deed, with the form of ownership chosen deliberately.
Parentage When You Aren’t Married
Marital status does not affect a child’s right to support from both parents, but it changes how legal parentage is established. A spouse is presumed to be a legal parent; for unmarried couples, there is no such presumption. A father typically establishes legal parentage by signing a voluntary acknowledgment of paternity at the hospital or through a later court proceeding. Federal law requires that both parents receive notice of the legal consequences and responsibilities before signing.6eCFR. 45 CFR 303.5 – Establishment of Paternity Once parentage is established, both parents have equal rights and obligations regardless of whether they married. Custody and visitation are decided on the child’s best interests, not the parents’ marital history.
Survivor Benefits Require a Recognized Marriage
Social Security survivor benefits go to a surviving spouse, and the Social Security Administration will treat a common law marriage as valid only if it was valid under the law of the state where the couple lived. Preferred evidence includes signed statements from both spouses, or from the surviving spouse and blood relatives of the deceased, explaining why they believed a valid marriage existed.7Social Security Administration. Evidence of Common-Law Marriage The Department of Veterans Affairs takes a similar approach and recognizes a common law marriage if the state where the veteran lives or lived recognizes it and its requirements were met.8VA.gov. Important Information on Marriage Partners without any recognized marriage do not qualify for either Social Security survivor benefits or VA spousal benefits. There is no workaround; only a legal marriage closes that gap.
Civil Unions as an Alternative
Since 2011, Illinois has allowed civil unions for both same-sex and opposite-sex couples. A civil union provides many of the state-level rights associated with marriage, including property rights, inheritance protections, and the ability to make medical decisions for a partner. State employees can add civil union partners to group health insurance. A civil union does not guarantee the same treatment as marriage under federal law for every purpose, and the interaction with federal benefits can be complicated. For couples who want state-level protections without marrying, it’s worth discussing with an attorney who can spell out what a civil union does and does not cover in your specific circumstances.