Responding to an Illinois complaint: 30 days, and why an unanswered allegation is admitted

Illinois procedure · Last verified August 17, 2026

Illinois splits its civil procedure between two sources, and a defendant needs both. The deadline comes from the Supreme Court Rules. What the response has to say comes from the Code of Civil Procedure. Missing either half is the common failure.

Thirty days, counted from delivery

Illinois Supreme Court Rule 181(a):

When the summons requires appearance within 30 days after service, exclusive of the day of service (see Rule 101(d)), the 30-day period shall be computed from the day the copy of the summons is left with the person designated by law and not from the day a copy is mailed, in case mailing is also required.

Where service involves both leaving a copy and mailing one — Illinois substituted service does — the clock runs from the leaving, not the mailing. That is the opposite of California, where substituted service is complete on the 10th day after the mailing, and of New York, where 308(2) service completes ten days after proof is filed.

The day of service is excluded.

Appearance and answer are two filings

Rule 101(a) requires every civil summons in Illinois to carry substantially this language:

You have been sued. … To participate in the case, you MUST file an official document with the court within the time stated on this Summons called an "Appearance" and a document called an "Answer/Response". The Answer/Response is not required in small claims or eviction cases unless ordered by the court. If you do not file an Appearance and Answer/Response on time, the court may decide the case without hearing from you, and you could be held in default and lose the case.

Two documents, and the summons says so. Note the carve-out — no answer is required in small claims or eviction cases unless the court orders one. The eviction guide covers what that means in practice.

Filing a motion instead

Rule 181(a) continues: "The defendant may make his or her appearance by filing a motion within the 30-day period, in which instance an answer or another appropriate motion shall be filed within the time the court directs in the order disposing of the motion."

So a timely motion is itself an appearance, and it replaces the 30-day answer deadline with whatever the court sets when it rules. There is no fixed 14- or 20-day period as in the federal rules, Georgia or North Carolina — Illinois leaves it to the order.

If the defendant appears some other way, the answer or motion is still due on or before the last day they were required to appear.

Rule 181(b) covers summonses that require appearance on a specified day, which is how many actions for money and eviction cases are set.

The jurisdiction objection has to come first

735 ILCS 5/2-301(a): prior to filing any other pleading or motion other than as subsection (a-6) allows, a party may object to personal jurisdiction — on the ground that the party is not amenable to process of an Illinois court, or that process or service of process was insufficient — by moving to dismiss or to quash service.

Two requirements attach:

The motion may be made singly or in a combined motion, "but the parts of a combined motion must be identified in the manner described in Section 2-619.1."
"Unless the facts that constitute the basis for the objection are apparent from papers already on file in the case, the motion must be supported by an affidavit setting forth those facts."

And 2-301(a-6) supplies the consequence:

A party filing any other pleading or motion prior to the filing of a motion objecting to the court's jurisdiction over the party's person as set forth in subsection (a) waives all objections to the court's jurisdiction over the party's person.

Anything filed first — even a routine motion — waives it. This is the same ordering discipline as Texas Rule 120a and CPLR 320(b), and it is unforgiving in the same way.

What the answer has to say

This is where Illinois departs sharply from Texas-style general-denial practice.

735 ILCS 5/2-610(a): "Every answer and subsequent pleading shall contain an explicit admission or denial of each allegation of the pleading to which it relates."

735 ILCS 5/2-610(b):

Every allegation, except allegations of damages, not explicitly denied is admitted, unless the party states in his or her pleading that he or she has no knowledge thereof sufficient to form a belief, and attaches an affidavit of the truth of the statement of want of knowledge, or unless the party has had no opportunity to deny.

Three things follow.

Silence admits. An allegation left unaddressed is admitted by operation of the statute.

Want of knowledge needs an affidavit. Pleading "defendant lacks knowledge sufficient to form a belief" is not enough on its own. The subsection requires an attached affidavit swearing to the truth of that statement of want of knowledge.

Damages are excepted. Allegations of damages are outside the admission rule, and 2-610(d) lets a party contest the amount alone: "If a party wishes to raise an issue as to the amount of damages only, he or she may do so by stating in his or her pleading that he or she desires to contest only the amount of the damages."

2-610(c): "Denials must not be evasive, but must fairly answer the substance of the allegation denied."

Affirmative defenses and alternative pleading

735 ILCS 5/2-613(d) requires the facts constituting an affirmative defense — the subsection names payment, release, satisfaction, discharge, license, fraud, duress and others — to be pleaded.

2-613(a): parties may plead as many causes of action, counterclaims, defenses and matters in reply as they have, "and each shall be separately designated and numbered."

2-613(b): a party in doubt as to which of two or more statements of fact is true "may, regardless of consistency, state them in the alternative or hypothetically in the same or different counts or defenses. A bad alternative does not affect a good one."

2-613(c) matters for anyone raising threshold defenses: defenses to subject-matter jurisdiction, in abatement, or in bar may be pleaded together without waiving any of them, and the court may order the jurisdiction or abatement defenses tried first. Crucially — "An answer containing only defenses to jurisdiction of the subject matter or in abatement does not constitute an admission of the facts alleged in the complaint."

Written instruments must be attached

735 ILCS 5/2-606: if a claim or defense is founded on a written instrument, a copy — or so much of it as is relevant — "must be attached to the pleading as an exhibit or recited therein," unless the pleader attaches an affidavit stating facts showing the instrument is not accessible.

And: "In either case the exhibit constitutes a part of the pleading for all purposes."

That matters in debt cases in both directions. A plaintiff suing on a contract must attach it. And because the exhibit is part of the pleading, it can be used on a motion attacking the pleading.

Extensions

Illinois Supreme Court Rule 183: "The court, for good cause shown on motion after notice to the opposite party, may extend the time for filing any pleading or the doing of any act which is required by the rules to be done within a limited period, either before or after the expiration of the time."

One standard — good cause — on both sides of the deadline, like New York's CPLR 2004 and unlike the federal rules' excusable-neglect test for late requests. But note Rule 183 requires a motion after notice; it does not authorize the court to act on its own or without notice.

If nothing is filed

735 ILCS 5/2-1301(d) permits a default judgment for want of an appearance or for failure to plead. Illinois then gives two routes back: 2-1301(e) within 30 days of entry, on terms that "shall be reasonable," and 2-1401 by petition for up to two years. The guide on setting aside an Illinois default covers both.

The order of operations

Calendar 30 days from the day the summons was left with you — not from the mailing, and not counting the day of service.
If personal jurisdiction or service is in question, file that motion first. 2-301(a-6) waives the objection if anything else is filed before it.
File an appearance and a response. Both, per Rule 101(a).
Answer allegation by allegation. 2-610(b) admits whatever isn't explicitly denied — and a want-of-knowledge answer needs an attached affidavit.
Plead affirmative defenses, separately designated and numbered.
If you need more time, Rule 183 allows it before or after expiry, on motion with notice.

Where these rules live

The Illinois courts publish self-help material and standardized forms at illinoiscourts.gov, and Illinois Legal Aid Online maintains guidance for people sued in debt cases. This page explains what the rules and statutes say. It isn't legal advice.

How this guide is sourced. Every procedural statement here is drawn from the text of the rules named above, each of which is reproduced verbatim on its own page on this site. Quoted rule language appears in quotation marks or block quotes; everything else is original writing. Last verified August 17, 2026.

This page explains what the rules say. It is legal information, not legal advice, and it cannot tell you how a rule applies to your situation. Deadlines are often short and some are not extendable — if the outcome matters, talk to a lawyer or your court’s self-help center.