Detailed Answer — How Illinois law treats unauthorized occupants and how to remove them

Short answer: In Illinois, an unauthorized occupant (commonly called a squatter) generally must be removed through the civil eviction process (forcible entry and detainer) or—if the situation involves immediate criminal activity—through police action. A squatter can only obtain legal title through adverse possession if they meet strict statutory requirements (including long continuous possession). You should avoid self-help measures (changing locks, forcibly removing people or their belongings) because those can expose you to civil and criminal liability.

1. Who is a “squatter” under Illinois law?

“Squatting” describes a person occupying real property without the owner’s permission. They are different from a tenant with a lease. Whether the law treats someone as a squatter, tenant, or adverse possessor depends on facts: did the occupant pay rent or sign an agreement, were they given keys or access, how long have they resided there, and how open and continuous was their possession?

2. Criminal vs. civil options

Criminal: If the person is committing a crime (breaking in, stealing, threatening violence), call police. Criminal trespass laws may apply and police can remove a trespasser when a crime is happening. See Illinois criminal trespass provisions (Illinois Criminal Code, chapter on trespass) for details. When the issue is purely occupancy or possession without other criminal acts, police will often view it as a civil matter.

Civil: In most situations you must use Illinois’ forcible entry and detainer (eviction) process to regain possession. This gives the occupant a court hearing and, if you win, a court order (writ of possession) enforced by the sheriff. The applicable civil procedure appears in the Illinois Code of Civil Procedure governing forcible entry and detainer actions (735 ILCS 5/9-101 et seq.). For statute language and procedure, see the Illinois General Assembly site: https://www.ilga.gov/legislation/ilcs/ilcs.asp and search 735 ILCS 5 (Code of Civil Procedure).

3. Adverse possession and the risk of losing title

An occupant may attempt to claim title by adverse possession. Under Illinois law, adverse possession claims require meeting strict elements: actual, open and notorious, exclusive, hostile, and continuous possession for the statutory period. Illinois’ statutory periods are long—commonly 20 years for most adverse possession claims—so a short-term squatter is unlikely to obtain title before a sale. If you have concerns about a long-term occupant, consult an attorney promptly. For statutory text and details, consult the Illinois Compiled Statutes on adverse possession (search 735 ILCS for chapter on possession/adverse possession at https://www.ilga.gov/legislation/ilcs/ilcs.asp).

4. Typical steps to remove an unauthorized occupant before closing a sale

1. Confirm status and document everything. Take photos, record dates and times of occupancy, save communications, and note any rent or utilities paid. This documentation matters in court.
2. Contact the title company and your attorney. The title company needs to know about occupancy because it may affect closing and title insurance. If you have a pending sale, consider contract provisions requiring seller to deliver possession at closing; consult counsel to add protections (e.g., holdover damages, escrow for removal costs).
3. Send a written demand to vacate. A clear written notice asking the occupant to leave by a certain date can be evidence in court that you tried to resolve the matter peacefully.
4. File a forcible entry and detainer (eviction) action if they refuse. This is the standard civil route: file a complaint in the appropriate county court, serve the occupant, attend the hearing, obtain a judgment for possession if you prevail, and receive a writ of possession for the sheriff to enforce. See Illinois Code of Civil Procedure forcible entry and detainer provisions (735 ILCS 5/9-101 et seq.).
5. Use the sheriff to carry out the writ of possession. Only a court-ordered writ allows law enforcement to remove occupants and their belongings legally.
6. Handle personal property carefully. If the occupant leaves personal property behind, follow local statutes and court orders for storing or disposing of abandoned personal property. Do not throw things out or sell them without following proper procedure—doing so can create liability.

5. Timing and cost

Eviction cases typically take several weeks to a few months depending on court schedules and any defenses the occupant raises. Expect filing fees, service fees, and sheriff charges; attorney fees if you hire counsel; and potential additional costs if you need storage for the occupant’s belongings or repairs to secure the property. If a prospective buyer is involved, these delays can jeopardize closing dates—work closely with your title company and buyer’s agent.

6. Common occupant defenses and complications

• Claims to be a tenant (oral lease or implied tenancy). Accepting rent or allowing regular occupancy can create tenant-like rights.
• Claims of adverse possession if the occupant alleges long-term, continuous use.
• Disputes over ownership or authority to evict (e.g., property in probate or owned by a trust). A court must resolve those.

7. Why you should avoid self-help

In Illinois, forcibly removing an occupant (changing locks, removing people or possessions yourself, turning off utilities) can lead to lawsuits for wrongful eviction, conversion of personal property, or criminal charges. Use the court process to avoid those risks.

8. Practical tips for sellers and buyers

Sellers: Add clear possession and closing conditions to the contract. Communicate issues early to the buyer and title company. Consider obtaining a court order before the closing if occupancy is contested.

Buyers: Insist on a negotiated credit, escrow holdback, or delayed closing if the seller cannot deliver vacant possession. Obtain title insurance and consult an attorney if the property is occupied.

Relevant Illinois resources and statutes

• Illinois Code of Civil Procedure (forcible entry and detainer) — search 735 ILCS 5, Article IX: https://www.ilga.gov/legislation/ilcs/ilcs.asp
• Illinois statutes on criminal trespass and the Criminal Code — search 720 ILCS 5 on the Illinois General Assembly site: https://www.ilga.gov/legislation/ilcs/ilcs.asp
• Illinois Courts (general information and local court contacts): https://www.illinoiscourts.gov/

Disclaimer: This article is informational only and does not constitute legal advice. Laws change and every situation is different. Consult a licensed Illinois attorney promptly for advice specific to your property and facts.

Helpful Hints

• Document occupancy immediately: photos, written statements, dates and any communications.
• Do not accept rent or provide keys if you want to avoid creating a tenancy.
• Contact your title company as soon as you learn of an occupant—title insurers and closing agents must be informed.
• Use written notices before filing court actions to show you attempted a peaceful resolution.
• Hire an Illinois real property attorney when possible—evictions and adverse possession claims become technical quickly.
• Avoid self-help removals; always seek a court order for removal to prevent liability.
• If you fear violence or immediate criminal activity, call police—but understand police often treat straightforward occupancy disputes as civil matters.