Bought a House with Your Boyfriend or Girlfriend? What Illinois Law Says When You Split Up

Illinois Does Not Recognize Common Law Marriage

In Illinois, it does not matter if you lived together for 15 years, raised children, and told your families you were married. Unless you have a marriage certificate, you are legal strangers when it comes to property division. The Illinois Marriage and Dissolution of Marriage Act (750 ILCS 5/103) requires a license and solemnization. Without that, there is no marital estate, no equitable distribution, and no family court judge splitting things up.

Your rights come from the deed. If both names are on it, you are both owners, and the law of co-ownership governs how you separate. If only one name is on the deed, the person who is not on it generally has no ownership claim, regardless of how much they contributed to mortgage payments or renovations.

What Is a Partition Action

A partition action is a lawsuit under 735 ILCS 5/17-101 that asks the court to divide co-owned property. For a house or condo, "divide" means sell. You cannot split a building in half. The court orders the property sold, pays off the mortgage from the proceeds, and divides what remains between the co-owners.

Any co-owner can file at any time. You do not need the other person's consent, and you do not need to prove wrongdoing. The right to partition is absolute in Illinois. The court must grant it unless the parties reach a different agreement on their own.

The case is filed in the Chancery Division of the circuit court where the property sits. The complaint names the co-owners and any lienholders. If the parties cannot agree on a listing agent or sale terms, the court appoints a commissioner to run the process.

The Timeline

Contested partition cases run 6 to 18 months from filing to final distribution. The court has to determine ownership interests, sort out who paid what, handle any appraisal disputes, supervise the listing and sale, and distribute the proceeds. If one side is dragging their feet, the court can order compliance, but enforcement adds more time.

When both parties agree to sell and can cooperate on choosing a realtor, the whole thing can wrap in 3 to 6 months. The delay in contested cases usually comes down to arguments about valuation, arguments about credits for contributions, and whether one party should get a chance to buy the other out.

How You Hold Title Matters

The deed you signed at closing specified how you hold title. Most unmarried couples end up as joint tenants with right of survivorship, often because the closing attorney or title company defaulted to it and nobody asked questions. Some take title as tenants in common. The difference matters when the relationship ends.

The survivorship feature of joint tenancy is what catches people off guard. If your co-owner dies while you still hold title together, you own the entire property automatically, bypassing probate. That is a real benefit during the relationship. But it also means that if you break up and your ex dies before the partition resolves, the surviving party inherits everything. People who have been fighting for months over equity suddenly have a very different problem if something happens to one of them.

How These Cases Actually Play Out

FHA Mortgage Assumption

During the pendency of the case, there was talk about retaining the property through an FHA mortgage assumption instead of forcing a sale. FHA loans originated before a certain date are assumable, meaning the party who wants to keep the house can take over the existing loan, with the lender's approval, and remove the departing party from the note entirely. In this case, the existing rate was 3.625%. New purchase rates in 2023 were above 7%. Over the remaining life of the loan, that rate difference represented over $150,000 in total interest costs.

This is why assumptions matter in partition cases. If the property carries a below-market rate, a forced sale destroys that locked-in value for everyone. The buyer gets a new loan at market rates. The co-owners split whatever equity is left after commissions and closing costs. An assumption lets one party keep the favorable financing while the other walks away with cash and a clean break from the mortgage obligation.

Assumptions require the lender's approval, a creditworthy assuming party (sometimes with a cosigner), and a negotiated payout to the departing co-owner for their equity share. They are not simple, but in a rising-rate environment, they save real money compared to a forced sale and refinance.

The Court's Order

The court was not willing to wait indefinitely. After hearing arguments, the judge ordered the property listed for sale within 21 days and ordered both parties to cooperate in selecting a listing agent. The message from the bench was plain: work it out between yourselves, or the court will do it for you, and neither side will like the result as much as the one they could have negotiated.

Attorney Fees: The Part Nobody Talks About

In a partition action, the party who petitions for the sale can recover their attorney fees from the sale proceeds. Read that again. If your ex files a partition action to force the sale and you refuse to cooperate, you are not just losing the house. You are paying for their lawyer too.

I see the same pattern over and over. The boyfriend wants to keep the property. The girlfriend wants to sell and move on. She files partition. He drags his feet, misses court dates, refuses to agree on a listing agent, and stalls for months. By the time the court finally forces the sale, her legal fees are $15,000 to $20,000, and the court orders those fees paid from the proceeds before anyone sees a dollar of equity. He ends up losing the house anyway, and he effectively paid for both sides of the litigation by refusing to engage.

If someone files a partition action against you, take it seriously. Hire an attorney. Respond to the complaint. Come to the table with a buyout proposal or agree to cooperate on the sale. The worst thing you can do is ignore it, because the court will proceed without you and you will pay for the privilege.

Accounting: Who Paid What

The court does not just split the sale proceeds 50/50 and close the file. There is an accounting phase where each party's contributions are tallied and the distribution is adjusted. This is where the real fight happens in most partition cases.

What Counts as a Contribution

Mortgage payments made after the separation count, including principal, interest, taxes, and insurance. Same with property tax payments made by one party alone, insurance premiums, necessary repairs that preserved the property's value, unequal down payment contributions, and capital improvements that increased market value (new roof, HVAC, a kitchen renovation that actually adds resale value).

What Does Not Count

Occupancy is its own category. The party living in the property after the split may owe the other party fair rental value for exclusive use. This cuts both ways: the occupying party gets credit for mortgage payments but may owe rent for having the place to themselves. Beyond that, cosmetic upgrades that did not increase market value, utility payments for the occupying party's benefit, and any claim based on the emotional labor of the relationship are all off the table. Illinois courts do not award property interests based on who did more around the house.

The accounting phase runs on documentation. Bank statements, cancelled checks, receipts, contractor invoices, tax records. If you have been paying the full mortgage since the breakup, start organizing those records now. The party with better paperwork gets the better result.

The Buyout: How to Keep the House

A buyout is almost always cheaper than a forced sale. In a partition sale, the property goes on the market under conditions that do not produce the best price. Both parties are paying lawyers, the listing period adds months of carrying costs, and the buyer can see from the lis pendens that this is a distressed situation. Offers come in accordingly.

In a buyout, one party keeps the property and compensates the other for their equity. The departing party gets cash and a clean break from the mortgage. Nobody pays a realtor commission. The property does not sit on the market for four months while two ex-partners try to agree on showing schedules.

What a Buyout Requires

Both parties need to agree on the property's value, either by getting an independent appraisal or negotiating a number. From there, you subtract the mortgage balance to calculate equity, adjust for each party's contributions in the accounting, and determine what the buying party owes the departing party. The buying party then refinances the mortgage into their name alone (or assumes the existing loan if the lender allows it), and the departing party executes a quitclaim deed. The whole process typically takes 60 to 120 days. If the buyout does not close within the agreed window, the partition moves forward to a sale.

A buyout negotiation, by contrast, can often be handled for a fraction of that. The variables are the property value, the mortgage balance, and what each party has contributed. When the numbers are clear and both people are willing to be reasonable, the negotiation is straightforward. The problem is that by the time people call me, reasonable has usually been off the table for months.

Lis Pendens and the Mortgage

When a partition action is filed, the plaintiff typically records a lis pendens against the property. This is a public notice that litigation is pending, and it shows up on any title search. The property cannot be sold or refinanced while it is in place without first resolving the lawsuit.

The lis pendens protects against one party selling or encumbering the property behind the other's back. It also means neither side can refinance, take out a home equity loan, or transfer the property into an LLC until the case is resolved.

The Mortgage Problem

The mortgage does not care about your breakup. Both names are on the note. Both parties are liable for the full payment. If one of you stops paying, the lender comes after both of you. Missed payments hit both credit scores. If it goes all the way to foreclosure, the deficiency judgment follows both borrowers.

This is the leverage that drives most partition cases toward settlement. The party who wants to sell is watching their credit score drop every month the other party does not pay. The party who wants to keep the house needs money to buy out the other side. Both people have a financial incentive to resolve the case, and judges know that, which is why they push hard for settlement.

The Cost of Doing Nothing

I see the same thing repeatedly. The couple breaks up. One moves out. The other stays. Neither wants to deal with the house because it means dealing with each other. Months pass. Then years.

Every month costs money. The person in the house is paying a mortgage that benefits both owners but getting no formal credit for it. The person who moved out has their credit at risk if payments lapse. The property may be deteriorating. And if the market shifts, the equity position changes for both sides in ways neither of them planned for.

Co-Ownership Agreements: How to Avoid All of This

If you are reading this before buying a house with your partner, you are in a good position. A co-ownership agreement signed at closing addresses every problem in this article before it becomes a crisis. Think of it as a prenup for the house, except you do not need to be getting married to need one.

The agreement is a contract between the co-owners that covers what happens if the relationship ends, if one party wants out, if someone stops paying, or if someone dies.

What It Should Cover

• Ownership percentages and how they relate to financial contributions
• Buyout rights: if one party wants out, the other gets first right of refusal at appraised value
• A buyout timeline, typically 90 to 120 days, with a forced sale trigger if the buyout does not close
• Payment obligations and what happens if someone stops paying (the other party makes the payment and receives an equity credit)
• Occupancy rights, including whether the occupant owes rent to the non-occupant
• How renovation costs are shared and how they affect the equity split
• Mediation before litigation, with the cost shared equally

I draft these as part of my closing representation. If you are buying with someone you are not married to, bring it up at the closing consultation. A co-ownership agreement costs a fraction of what partition litigation costs, and it eliminates the uncertainty that makes these disputes so expensive and so ugly.

Call Me and Tell Me Where Things Stand

Buying a house with someone you are not married to is not illegal. But it creates a co-ownership arrangement with no built-in exit ramp. When married couples divorce, Illinois law has a structured process for dividing marital property. When unmarried couples split, the only option is a partition action, a statute originally designed for co-owners of farmland, applied to couples who bought a condo together last year.

If you are already in this situation, the priority is getting to a resolution. The longer you wait, the more it costs both of you. If you are about to buy property with a partner, get a co-ownership agreement at closing. It is the cheapest insurance you will ever buy.

Either way, call my office. Tell me the property address, who is on the deed, who is on the mortgage, and whether your ex is being reasonable. I will tell you what your options are and what they cost.

Related Guides

If you are buying property with a partner and want closing representation that includes a co-ownership agreement, read the closing attorney guide. For investors acquiring properties through LLCs that sidestep co-ownership complications entirely, the investor services guide covers entity structuring. If you need to transfer a property interest into an LLC after resolving a co-ownership dispute, the transfer guide walks through the process.

Published: April 2026

Justin Abdilla Named Attorney, Abdilla & Associates · ARDC #6308444

Justin Abdilla has worked on over 700 files across twelve years of practice, handling closings, evictions, construction disputes, zoning applications, and creative investor transactions across Cook, DuPage, Kane, and Lake counties. Super Lawyers Rising Stars 2021-2026. Published in SSRN. Quoted in the Chicago Tribune. Last updated: April 2026.