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Undisputed Legal | Illinois Process Service

Illinois Process Service is how a party to a case presents an effective notice of preliminary legal action to another party (such as the defendant), a court, or an administrative entity in an attempt to exert control over that person. This is designed to facilitate that party to respond to the proceedings before a court, body, or other tribunal and bring them under that body’s personal jurisdiction.

Notice is given by the issuance of a set of court documents (process) to the individual.  A court has personal jurisdiction when it can decide for the party being sued in a case. Before a court can exercise power over a party, the U.S. Constitution requires that the party has certain minimum contacts with the forum in which the court sits.

While there is no actual state-wide licensing law in Illinois, Illinois Process Service requirements can be complex in this state. In fact, Cook County [Chicago] imposes additional guidelines, complicating licensing requirements.


Licencing in Illinois includes being a private detective. This means that a ‘private detective’ licensed in Illinois may serve the original process in all counties except for Cook County without a designated appointment. A private detective agency is most often appointed Illinois Process Service. However, private individuals over the age of eighteen can specifically be appointed to serve the original process upon the court’s motion.

Individuals who are not a private agency are required to [A.] provide legal photo identification [B.] complete an application for appointment filed at the resident county court, [C.] undergo a criminal background check, and [D.] pay for the processing and fingerprinting fees. Cook County requires private detective agencies to be appointed by the court on the motion as a special process server.

Illinois Process Service is the responsibility of the sheriff. If the sheriff is otherwise incapacitated or disqualified, then a coroner of some county of the state is responsible for the same. A sheriff who is the head of a county with a population that falls below two million individuals, civil personnel may be employed to serve the process. However, if there are less than two million individuals, the process may be served without the need for special appointment by a person who is [A.] licensed or registered as a private detective under the Private Detective, Private Alarm, Private Security, and Locksmith Act of 2004 or [B.] a registered employee of a private detective agency certified under that Act. A private detective or licensed employee does require to authenticate themselves to the county’s sheriff by furnishing a copy of their license or certificate. Despite the same, the process itself is valid even if the individual does not supply this copy. 

In its discretion upon motion, the court may order service to be made by a private person over eighteen years of age and not a party to the action. A sheriff or coroner doesn’t need to make service of the county in which service is made. If served or sought to be served by a sheriff or coroner, they shall endorse their return thereon, and if by a private person, the return shall be by affidavit. It must be remembered that intentional resistance of obstruction of an authorized service or execution or any civil or criminal process as well as the order of any court is a Class B misdemeanor. 


There are a variety of ways that a person can be served in Illinois. Before serving the party in a case, the plaintiff must file a complaint, request a summons, and provide copies to the county clerk.

All lawsuits start with the filing of the complaint, upon which the clerk can then file a complaint. The form and content of the same are understood as per Supreme Court Rule 101, wherein the summons needs to be issued under the court’s seal, identifying the name of the clerk. Furthermore, the summons has to [A.] clearly identify the date it is issued, [B.] be directed to each defendant, and [C.] bear the information required by Rule 131(d) for the plaintiff’s attorney or the plaintiff if not represented by an attorney. E-filing is mandatory for documents in civil cases with limited exemptions.

In action for below USD 50,000, or in any action subject to mandatory arbitration where local rule prescribes a specific date for appearance, the summons requires each defendant to appear on a day specified in the summons. This would not be less than twenty-one or more than forty days after the summons’ issuance and is prepared by utilizing, or substantially adopting the appearance and content of, the form provided in the Article II Forms Appendix.

In any action for eviction or recovery of possession of the tangible personal property, the summons shall be in the same form. Still, it shall require each defendant to appear on a day specified in the summons not less than seven or more than forty days after the summons’ issuance.

In general, the summons requires each defendant to file their answer or otherwise file his appearance within 30 days after service, exclusive of the day of service, and shall be prepared by utilizing or substantially adopting the appearance and content of the form provided in the Article II Forms Appendix. However, the Illinois Marriage and Dissolution of Marriage Act and the matters under it require the summons to include a notice on its reverse side referring to a dissolution action stay being in effect on service of the summons and must state that any person who fails to obey a dissolution action stay may be subject to punishment for contempt. This means that the language is intended to be commanding since it has to [A.] restraining both parties from physically abusing, harassing, intimidating, striking, or interfering with the personal liberty of the other party or the minor children of either party; and [B.] restraining both parties from concealing a minor child of either party from the child’s other parent. The restraint provided in subsection (e) does not operate to make unavailable any of the remedies provided in the Illinois Domestic Violence Act of 1986.

In all cases in which a plaintiff notifies a defendant of the commencement of an action and requests that the defendant waives service of summons under the request shall be in writing prepared by utilizing, or substantially adopting the appearance and content of, the form provided in the Article II Forms Appendix.  The use of the wrong form of a summons does not affect the jurisdiction of the court.


Illinois specifies individuals who can legally serve process. The sheriff is the usual candidate to be assigned this role. If the sheriff holds sway over a county with a below two million demographic, the sheriff will hire civilian staff to conduct this role. If the county has a broader community, the process can be carried out by a person who is licensed or trained as a private detective or by a registered employee of a professional private detective firm. In this case, a private investigator or employee may supply the county sheriff with a copy of their license. If the sheriff is ineligible, the county coroner will serve the process. When the lawsuit has identified the county or state as an involved party, the county’s state attorney appoints a special investigator. as an interested party, the county’s state’s attorney appoints a special investigator.

If a party demands the service from a private citizen over the age of 18, it is acceptable for the court to grant this request as long as the individual is not a party to the action. Service can be done in one of four ways; wherein the server provides service by [A.] the sheriff; [B.] a detective or special process server; [C.]  certified mail, and, in some types of cases; [D.] publishing notice of the lawsuit in the local newspaper.


The individuals mentioned above can perform personal service on the defendant anywhere they can be found in the state. Officers can serve process outside their county. The process server can give the summons to the defendant personally or by leaving a copy of it at the defendant’s normal residence with another resident of the home who is at least 13 years old and sending a copy of the summons by mail to the defendant.

After serving papers, the authorized individual provides a return to the court in person or by mail in which he or she states the circumstances of service. Officers complete a certificate to this effect, while private citizens complete an affidavit. The sheriff will deliver the court papers to the defendant; however, the stamped summons and copies must be supplied or mailed to the sheriff’s office where the defendant lives. There is a fee for this service.  An addressed and stamped return envelope with the papers must be provided if the papers have been mailed.

 A licensed private detective or ‘special process server’ can also serve the court papers.  In most cases, the judge’s permission to do this must be sought by filing a ‘Motion for Appointment of Special Process Server.’ Once the person is served with notice of the lawsuit, the sheriff, detective, or process server fills out a sworn statement on the back of the summons copy and mails it back, or returns it to the circuit clerk. The returned summons shows the judge that the person knew about the case.


Unless otherwise provided by circuit court rule, at the plaintiff’s request and instead of personal service, service in small claims may be made within the state as long as the plaintiff pays a fee of USD 2 for each defendant to be served. This fee must be supplied to the court clerk along with the filed summons and an affidavit setting forth the defendant’s last known mailing address. Thereupon, the clerk is required to mail to the defendant, at the address appearing in the affidavit, the copy of the summons and complaint, certified or registered mail, return receipt requested, showing to who delivered and the date and address of delivery. United States Postal Service electronic return receipts may be utilized instead of paper receipts. 

The summons and complaint are mailed on a ‘restricted delivery’ basis when service is directed to a natural person. The envelope and return receipt should have the clerk’s return address, with the docket number of the case on the return receipt. The receipt should also include the name and address of the addressee, the date of mailing and must be filed by the clerk whereupon it can constitute proof of service if delivery is shown at a minimum of three days before the day appearance. The clerk is then required to note the fact of service in a permanent record.


If the defendant is hiding from service, has left the state, or his or her residence cannot be ascertained despite diligent attempts to do so, the county clerk can publish a notice in a newspaper in the county where the legal action is pending upon the plaintiff’s request and affidavit. If there is no published newspaper in the county, the publication can be in a newspaper in an adjoining county. The notice must include the court’s title, the case title, the names of the parties, the case number, the names of the parties being served via publication, and the date when default will be entered if there is no answer. The county clerk provides a copy of the publication by mail to the defendant’s last known address.  Service by publication requires the notice to be made at least once a week for three successive weeks.


In certain cases, allocation to a service acceptance agent or a ‘registered agent’ may substitute personal service to the principal party to be served. The registered agent denotes the person or organization approved in advance to receive the service on behalf of the institution served. For example, most companies are mandated by local legislation to retain a local service acceptance agent of the record in each jurisdiction where they voluntarily participate in business with the public. The service agent’s name may typically be ascertained by examining for company filings with relevant state corporate documents or corporation registry authorities (often the business entity division of the state Secretary of State). Generally, these business registration records are searchable by the public on the secretary of state’s website.

If the defendant is a private corporation, it can be served by leaving a copy of the legal documents with the agent registered with the state or with any officer or agent of the corporation located in the state. It can also be served by publication and mail-like individuals.


If the above methods do not work or are not practical, the plaintiff can request that the court enter an order that provides a comparable service method. An affidavit must support this motion that states what the plaintiff has done to determine the defendant’s whereabouts and why service is impractical under personal service or service by publication.

There are specific civil procedure codes in Illinois for individual instances, including representing partners in action or serving detainees. Persons who may not live in Illinois could also be served in Illinois if such contacts have been made with the State.

If the process is not performed appropriately, it will have to be initiated anew. In such cases, it can also impede the feasibility of legal proceedings. This procedure must be done properly not adversely to impact the interests of the claimant.

For more information on serving legal papers, contact Undisputed Legal our Illinois Process Service department at (800) 774-6922. Representatives are available Monday-Friday 8 am – 8 pm EST.  If you found this article helpful, please consider donating.  Thank you for following our blog, A space dedicated to bringing you news on breaking legal developments, interesting articles for law professionals, and educational material for all. We hope that you enjoy your time on our blog and revisit us!  We also invite you to check out our Frequently Asked Questions About Process Servers.


1. Home: New Website for the Cook County Clerk of the Circuit Court. (n.d.). Retrieved November 11, 2020, from

2. Return. The officer or person doing service shall make a return by filing a proof of service immediately after service on all defendants has been had, and, in any event, shall make a return: (1) in the case of a summons bearing a specific return day or day for appearance, not less than 3 days before that day; (2) in other cases, immediately after the last day fixed for service. If there is more than one defendant, the proof of service may be filed immediately after service on each defendant. The proof of service need not state whether a copy of the complaint was served. A party who has placed a summons with an officer or other person who is authorized to serve process but who does not have access to the court filing system shall file the proof of service obtained from the officer. Failure to return the summons or file proof of service does not invalidate the summons or the service thereof if had.

(e)Post Card Notification to Plaintiff. If the plaintiff furnishes a postcard, the officer or other person making service of the summons, immediately upon return of the summons, shall mail to the plaintiff or his attorney the postcard indicating whether or not service has been had if so on what date.

Rule 102 – Service of Summons and Complaint; Return, Ill. Sup. Ct. R. 102

3. Illinois Compiled Statutes §5/2-202

4. Illinois Compiled Statutes: Criminal Offenses, Criminal Cod of 1961. (720 ILCS 5/31-3) Sec 31-3. Obstructing service of process

5. 735  ILCS  5/2-201.

6. Rule 101 – Summons and Original Process-Form and Issuance, Ill. Sup. Ct. R. 101

7. Rule 283 – Form of Summons, Ill. Sup. Ct. R. 283

8. Exclusive of interest and costs

9. see Rule 181(a)),

10. Ill. S. Ct. R. 101 (eff. Jan. 1, 2018), Art. II Forms Appendix

11.“Illinois Marriage and Dissolution of Marriage Act” 750 ILCS 5/101

12. “Illinois Domestic Violence Act of 1986″ 750 ILCS 60/101

13. Section 2-213 of the Code of Civil Procedure,

14. Rule 284 – Service by Certified or Registered Mail, Ill. Sup. Ct. R. 284

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