(a) Within the time a party is to respond to a pleading, that party may, if allegations are so wanting in details that the responding party should be entitled to a bill of particulars, file and serve a notice demanding it. The notice shall point out specifically the defects complained of or the details desired. The pleader shall have 28 days to file and serve the bill of particulars, and the party who requested the bill shall have 28 days to plead after being served with the bill.
2-607.Bills of particulars.
Article II. Civil Practice · Part 6. Pleading · Not amended since adoption on record · Last verified July 20, 2026
In one sentenceA party facing a vague pleading can demand a bill of particulars within the time to respond, and if the pleader ignores the demand or gives an insufficient answer, the court can strike the pleading, extend the deadline, or order a fuller bill.
Full Text of 735 ILCS 5/2-607
(b) If the pleader does not file and serve a bill of particulars within 28 days of the demand, or if the bill of particulars delivered is insufficient, the court may, on motion and in its discretion, strike the pleading, allow further time to furnish the bill of particulars or require a more particular bill to be filed and served.
(c) If a bill of particulars, in an action based on a contract, contains the statement of items of indebtedness and is verified by oath, the items thereof are admitted except in so far as the opposite party files an affidavit specifically denying them, and as to each item denied states the facts upon which the denial is based, unless the affidavit is excused by the court.
(d) If the party on whom a demand for a bill of particulars has been made believes that the party demanding it is not entitled to the particulars asked for, he or she may move the court that the demand be denied or modified.
Plain-English Summary
The bill of particulars gives a party a way to pin down an opponent's pleading without filing a motion first. Within the time allowed to respond to a pleading, a party who finds the allegations too thin to answer properly can serve a notice demanding particulars, specifying exactly what's missing or unclear. The pleader then has 28 days to serve the bill, and the requesting party gets 28 days after that to plead.
Subsection (b) gives the demanding party leverage if the response falls short: on motion, the court can strike the pleading, give the pleader more time, or order a more particular bill. Subsection (c) adds a verification-linked consequence in contract actions -- if a bill of particulars states items of indebtedness under oath, those items are deemed admitted unless the other side files an affidavit specifically denying them and stating the facts behind the denial.
Subsection (d) protects the party on the receiving end of an overreaching demand: if that party thinks the request goes beyond what a bill of particulars should cover, it can move the court to deny or narrow the demand.
Frequently Asked Questions
What is a bill of particulars used for?
It lets a party demand more detail when an opponent's pleading is so short on specifics that the party can't respond to it properly. The demand must point out exactly what's missing or unclear.
How long does a party have to demand a bill of particulars?
The demand must be made within the time allowed to respond to the pleading in question.
How much time does the pleader get to provide the bill?
28 days from the demand. The party who requested it then has 28 days after receiving the bill to plead.
What can a court do if the bill of particulars is never provided or is inadequate?
On motion, the court may strike the pleading, allow more time to furnish the bill, or require a more particular bill to be filed and served.
Can a party push back on a bill-of-particulars demand it thinks is unfair?
Yes. A party who believes the demand asks for more than it's entitled to can move the court to deny or modify the demand.
Amendment History
(Source: P.A. 86-646.)
Source & verification. Section text and amendment history are
reproduced verbatim from the Illinois Compiled Statutes, published by the
Illinois Compiled Statutes, Illinois General Assembly / Legislative Reference Bureau. Last verified July 20, 2026.
· Official source
Also known as: bill of particulars illinoisdemand for more definite statement illinoisinsufficient complaint details illinois