1 September 2026
/ Cristopher J. Nolan
Answering the Most Common Questions about Service Process in Illinois
Serving a defendant may seem like a straightforward step in the litigation process, but what may seem like minor mistakes can lead to delays and other issues. From identifying the proper person to serve to documenting repeated attempts, service of process requires careful attention to the applicable rules and the facts surrounding each case.
In Episode 7 of our popular Commercial Collections Corner, Chicago Attorney Cristopher Nolan examined the practical challenges creditors and process servers can encounter when serving individuals and businesses in Illinois. Cris drew on his experience reviewing service affidavits and determining whether defendants or commercial entities have been properly served, with particular attention to what happens when traditional service is unsuccessful.
Key topics covered during the episode included:
- Fundamentals of the service process
- Who is authorized to serve?
- How to properly serve individuals and businesses
- What information should be included in a service affidavit?
- How detailed documentation can support a request for alternative service
Watch the full episode to hear Cris walk through Illinois service requirements, common service challenges and practical strategies for handling difficult-to-serve defendants.
Top Questions Answered about Effectuating Service
1. Who is authorized to serve process in Illinois?
It’s important to know that Illinois requirements regarding process servers changed in 2025.
Previously, Cook County had separate requirements that generally required an initial attempt by the sheriff before a private process server could be used. This distinction no longer applies. A private process server may now be used in Cook County and throughout Illinois without a special court appointment, provided the individual is properly licensed or registered as a private detective under Illinois law.
The sheriff remains an option for service, and in certain circumstances an attorney can ask the court to authorize another person who is over 18 and not a party to the case to serve process.
The key takeaway is that selecting an authorized process server is an important first step. Even a technically correct service attempt can create problems if the person performing the service was not authorized to do so.
2. How do you properly serve an individual defendant?
For individual defendants, the preferred approach is generally personal service on the defendant. However, Illinois law also permits substitute or “abode” service in certain circumstances.
Under the requirements discussed in episode 7, a process server may leave the summons with a family member or another person residing at the defendant’s home who is at least 13 years old. But the process does not end there. The person receiving the documents must be informed of their contents, and a copy of the summons must subsequently be mailed to the defendant at the place of abode.
The follow-up mailing is of critical importance. Cris emphasized that service through a household member is not complete simply because the summons was handed to someone at the residence. The required mailing must also occur, and the service affidavit should document that step.
Process servers should also gather identifying information about the person who accepted service, including their name, relationship to the defendant and confirmation that they actually reside at the location. The service affidavit should also note the approximate age and include physical description of the person accepting service.
The lesson: When substitute service is used, documentation matters just as much as the initial handoff.
3. What should be included in the service affidavit?
A service affidavit should tell the court what actually happened, rather than simply providing a conclusion.
For example, a statement such as “no contact” provides very little context. A detailed affidavit could instead explain that the process server knocked on the door, heard a dog inside the residence, observed a vehicle in the driveway, saw a doorbell camera and received no response.
Those details help establish whether the defendant likely resides at the location and whether service may be intentionally avoided.
Other important details to document can include:
- The exact address where service was attempted
- The date and time of each attempt
- Who answered the door, if anyone
- Conversations with residents, neighbors, doormen or property managers
- The identity, physical description and approximate age of anyone accepting substitute service
- Vehicles observed at the property and relevant identifying information
- Packages or other observations connecting the defendant to the address
- Security cameras or other evidence that may indicate someone is screening visitors
- Other facts that support the conclusion that the defendant lives at the location
The goal isn't to create unnecessary paperwork. It is to create a factual record that allows an attorney and, ultimately, a judge to understand what happened.
4. What to do when a defendant appears to be avoiding service?
Visiting the same address at the same time of day over and over again may not be enough to demonstrate reasonable diligence.
For instance, a process server may visit the defendant’s address in the morning, afternoon, early morning and evening while also documenting observations along the way. Although the defendant never answered the door, the server may observe a dog inside the home, vehicles associated with the defendant, an open garage and packages bearing the defendant’s name.
Individually, these observations may seem minor. Together, however, they can create a more compelling record for the court. Judges do not simply count service attempts—they are evaluating the quality of those attempts.
Four identical attempts that simply state “no answer” may tell a judge very little. Attempts made at different times and on different days, accompanied by detailed observations, provide a much stronger and clearer picture of the circumstances.
5. When can alternative or electronic service be used?
When traditional service isn't working, Illinois law provides options for requesting service by special order of the court.
Cris discussed 735 ILCS 5/2-203.1, which provides a path toward alternative methods of service when reasonable diligence has been demonstrated. Depending on the circumstances, alternative service can include posting, publication or certain electronic methods.
Recent changes to Illinois Supreme Court Rule 102(f) also allow courts to order electronic service through methods such as email, text message and/or social media.
However, electronic service isn't necessarily a shortcut. The party requesting electronic service must provide evidence supporting the request, including why there is reason to believe the defendant has recently used the relevant email address or telephone number or maintains an active social media account on the platform proposed for service.
The webinar's message was clear: build the record first.
Traditional service attempts, detailed process-server notes and supporting information can help demonstrate reasonable diligence. Additional documentation, such as recent communications between the client and defendant, may also help establish that the defendant actually uses the proposed electronic method.
6. How do you serve a corporation or other business entity?
For a private corporation, service may generally be made on the corporation's registered agent or an officer or agent authorized under the applicable law.
This is where preliminary research can make the process much more efficient. Cris explained how Illinois Secretary of State records can be used to determine whether a business is active, identify its registered agent, locate the registered office and find information about company officers.
But what happens when a process server arrives at the business and is greeted by a manager or administrative employee? The answer may not be as simple as handing over the papers.
A person who manages a store or happens to be the only employee present may not have authority to accept service on behalf of the business. If the registered agent or appropriate officer cannot be located, the process server should carefully document who was contacted, that person's name and title, and what they said about the availability or location of the registered agent.
These details can become important if traditional service fails and another method of service needs to be pursued.
7. What happens when a business is dissolved or the registered agent cannot be found?
A business that cannot be served through its registered agent isn't necessarily the end of the road. Cris discussed an Illinois procedure that allows service through the Secretary of State when a corporation fails to maintain a registered agent or when the registered agent cannot be found after reasonable diligence at the registered office.
The process can depend on whether the business remains active or has been dissolved. For an active business, the general approach is to first establish a record of attempts to serve the registered agent or appropriate officer through traditional means. If those efforts fail, service through the Secretary of State may become an option.
For a dissolved business, Cris noted that service through the Secretary of State may be pursued from the outset. He also pointed out that a dissolved business can potentially be served for up to five years following dissolution.
The broader takeaway is that a failed attempt to locate a registered agent should be documented rather than treated as a dead end.
The Bottom Line: Service Is More Than Checking a Box
The central theme of episode 7 was that effective service is about more than simply making an attempt. It is about creating a reliable record that demonstrates diligence and supports the court's ability to determine whether the defendant received - or had a meaningful opportunity to receive - notice.
For process servers, that means taking detailed notes, varying the timing of attempts and documenting relevant observations. For attorneys and creditors, it means using those records and other supporting documentation to determine the next appropriate step when traditional service doesn't work.
As Cris explained during the webinar, the purpose of service is ultimately to provide a defendant with notice and an opportunity to be heard. When service becomes difficult, a detailed factual record can be critical to demonstrating that reasonable efforts were made while protecting the integrity of the litigation process.
Want to learn more? Watch the full Commercial Collections Corner Episode 7 for more insights into Illinois service requirements, in addition to practical examples and strategies for handling difficult service situations.
If you have questions on this topic or would like to learn more about Weltman's Commercial Collections Solutions, you can connect with Cris at any time.
This blog is not a solicitation for business, and it is not intended to constitute legal advice on specific matters, create an attorney-client relationship or be legally binding in any way.
