Illinois
Illinois Trade Secret Laws: UTSA, Remedies & Deadlines
Independently fact-checked against primary sources (last audited August 16, 2026). · Reviewed by the RecordingLaw editorial team. · Law checked current as of August 16, 2026. · 3 primary sources cited on this page. How we verify our legal content
Illinois protects confidential business information under the Illinois Trade Secrets Act (ITSA), 765 ILCS 1065/1 to 1065/9, enacted in 1987. The ITSA departs from the standard UTSA limitations period: plaintiffs have five years from discovery to bring a misappropriation claim (765 ILCS 1065/7), and the statute expressly recognizes customer and potential-customer lists as protectable trade secrets.
This guide is part of our Trade Secret Laws by State series.
Information last verified on 2026-06-25. This article presents general legal information, not legal advice. For guidance on a specific situation involving Illinois trade secret law, consult a lawyer licensed in Illinois. See also our Trade Secret Laws by State hub for additional state guides.
Does Illinois have a trade secret law?
Illinois enacted the Illinois Trade Secrets Act in 1987, codified at 765 ILCS 1065/1 to 1065/9. The ITSA is modeled on the Uniform Trade Secrets Act but contains several notable features, including an extended five-year limitations period and an express statutory recognition of customer and potential-customer lists as qualifying trade secrets. Under 765 ILCS 1065/8, the ITSA preempts conflicting tort, restitution, and other civil claims based on misappropriation of a trade secret, but does not affect criminal law, contract claims, or other non-misappropriation civil claims. Illinois courts have developed a substantial body of case law interpreting the ITSA, particularly in employment-related trade secret disputes.
What counts as a trade secret and misappropriation in Illinois?
Under 765 ILCS 1065/2(d), a trade secret is information, including but not limited to technical or non-technical data, a formula, pattern, compilation, program, device, method, technique, drawing, process, financial data, or list of actual or potential customers or suppliers, that:
- Is sufficiently secret to derive economic value, actual or potential, from not being generally known to other persons who can obtain economic value from its disclosure or use; and
- Is the subject of efforts that are reasonable under the circumstances to maintain its secrecy or confidentiality.
The explicit inclusion of lists of actual or potential customers and suppliers is a notable ITSA provision. Illinois courts have applied this provision to protect client databases, prospecting lists, and similar business development materials, provided the owner takes reasonable measures to keep them confidential. Generic or publicly available customer information is less likely to qualify.
Under 765 ILCS 1065/2(b), misappropriation means acquisition of a trade secret by improper means, or disclosure or use without consent by a person who obtained the secret through improper means, breach of a duty to maintain secrecy, or through a third party with knowledge of such circumstances. Improper means under 765 ILCS 1065/2(a) include theft, bribery, misrepresentation, breach of a duty to maintain secrecy, and espionage. Reverse engineering and independent development are lawful under 765 ILCS 1065/2(a).
Remedies and the limitations period in Illinois
Illinois offers the following remedies under the ITSA:
- Injunction: Under 765 ILCS 1065/3, courts may enjoin actual or threatened misappropriation. An injunction may condition future use on payment of a reasonable royalty when an absolute prohibition would be inequitable.
- Damages: Under 765 ILCS 1065/4, a plaintiff may recover actual loss caused by misappropriation plus unjust enrichment not captured by actual loss. Where neither measure is provable, courts may award a reasonable royalty for the period of unauthorized use.
- Exemplary damages: Willful and malicious misappropriation supports an award of up to twice the compensatory damages (765 ILCS 1065/4).
- Attorney fees: The court may award reasonable fees to the prevailing party when a claim of misappropriation is made in bad faith, a motion to terminate an injunction is made or resisted in bad faith, or when willful and malicious misappropriation is proven (765 ILCS 1065/5).
The limitations period in Illinois is five years from the date the misappropriation was discovered or, through reasonable diligence, should have been discovered (765 ILCS 1065/7). This is a material deviation from the three-year standard in the UTSA and in many other states. The longer period gives Illinois plaintiffs more time to identify and respond to misappropriation, which can be difficult to detect when it involves gradual competitive harm.
How the federal DTSA applies in Illinois
The Defend Trade Secrets Act, 18 U.S.C. §§ 1836-1839, has provided a federal civil remedy since May 2016 for misappropriation of trade secrets that relate to interstate or foreign commerce. The DTSA does not preempt Illinois law (18 U.S.C. § 1838), and Illinois plaintiffs routinely plead both statutes in a single action to access federal jurisdiction while preserving state remedies.
Key DTSA considerations for Illinois businesses include:
- A three-year federal limitations period from discovery (18 U.S.C. § 1836(d)), which is two years shorter than the Illinois state period. Choosing where to file can affect the available window.
- Ex parte seizure to prevent propagation of the secret, available in extraordinary circumstances (§ 1836(b)(2)).
- Exemplary damages up to twice and attorney fees for willful and malicious misappropriation, parallel to Illinois ITSA remedies.
- Whistleblower immunity: the DTSA immunizes individuals who disclose trade secrets to government officials or attorneys in connection with a suspected legal violation (§ 1833(b)(1)). Employers must include a notice of this immunity in confidentiality or non-disclosure agreements signed or updated after May 11, 2016 (§ 1833(b)(3)). Omitting the notice forfeits the right to claim exemplary damages and attorney fees under the DTSA.
Federal criminal exposure for trade secret theft may also arise under the Economic Espionage Act, 18 U.S.C. §§ 1831-1832.
This article provides general legal information about Illinois trade secret law as of 2026-06-25. It is not legal advice. Laws can change; consult a lawyer licensed in Illinois before taking action based on this information.
Related articles
- Trade Secret Laws by State
- Idaho Trade Secret Laws
- Indiana Trade Secret Laws
- Is AI-generated code copyright infringement?
Last updated: 2026-06-25.
Frequently Asked Questions
What qualifies as a trade secret under Illinois law?
Under 765 ILCS 1065/2(d), a trade secret is information sufficiently secret to derive economic value, actual or potential, from not being generally known to others who can obtain economic value from its disclosure or use, and that the owner protects through reasonable confidentiality measures. The Illinois statute expressly includes lists of actual or potential customers and suppliers, making it easier than in some states to protect client databases and prospect lists when reasonable precautions are in place.
How long do I have to sue for trade secret misappropriation in Illinois?
Illinois provides five years from the date the misappropriation was discovered or, through reasonable diligence, should have been discovered (765 ILCS 1065/7). This is longer than the three-year UTSA baseline used by most states. Note that a parallel DTSA federal claim carries only a three-year limitations period, so the choice of forum can affect how much time you have.
What damages are available in an Illinois trade secret case?
A prevailing plaintiff may recover actual loss plus unjust enrichment, or a reasonable royalty if neither measure is quantifiable. Willful and malicious misappropriation can yield exemplary damages up to twice the compensatory award. The court may award reasonable attorney fees to the prevailing party when misappropriation is willful and malicious or when a misappropriation claim is made in bad faith or a motion to terminate an injunction is made or resisted in bad faith. Courts may also issue injunctions to stop threatened or ongoing misappropriation.
Are customer lists protected as trade secrets under Illinois law?
Yes, explicitly. The ITSA, 765 ILCS 1065/2(d), lists actual or potential customers and suppliers among the categories of qualifying trade secrets. To obtain this protection, the business must show that the lists derive economic value from their secrecy and that the business takes reasonable steps to keep them confidential. Generic or publicly sourced contact information is unlikely to qualify.
Should I plead both the Illinois Trade Secrets Act and the federal DTSA?
In most cases, yes. Pleading both maximizes your forum options and remedies. The DTSA provides access to federal court and additional tools such as ex parte seizure. The ITSA's five-year limitations period can be advantageous for claims first discovered more than three years ago. Because the DTSA does not preempt Illinois law, there is generally no reason to choose one over the other. Consult Illinois counsel to evaluate the best strategy for your situation.
Updates
Corrected Illinois’s trade-secret definition and statutory grounds for attorney fees.
Fixed a broken government statute link that had pointed to an unrelated Illinois law (the Companion Animal Cremation Act) instead of the Illinois Trade Secrets Act.
Independently fact-checked against the cited primary sources; governing law re-checked for recent changes
Governing law re-checked for recent changes
Governing law re-checked for recent changes
Reviewed and approved by an editor
The Law Behind This Article
This article rests on the statutory provisions below, held in our own legal record and retrieved from the official source. Tap a section to read the operative text.
Illinois Compiled Statutes Chapter 765, Act 1065 (Illinois Trade Secrets Act)
§ 3(a) Actual or threatened misappropriation may be enjoinedIn force
Upon application to the court, an injunction may be terminated when the trade secret has ceased to exist, provided that the injunction may be continued for an additional reasonable period of time in appropriate circumstances for reasons including, but not limited to an elimination of the commercial advantage that otherwise would be derived from the misappropriation, deterrence of willful and malicious misappropriation, or where the trade secret ceases to exist due to the fault of the enjoined party or others by improper means. (b) If the court determines that it would be unreasonable to prohibit future use due to an overriding public interest, an injunction may condition future use upon payment of a reasonable royalty for no longer than the period of time the use could have been prohibited. (c) In appropriate circumstances, affirmative acts to protect a trade secret may be compelled by a court order.
Official text (excerpt) · last checked 2026-09-08 · Read the full text in our law library · Verify at ilga.gov
§ 2As used in this Act, unless the context requires otherwise: (a) "Improper means" includes theft, bribery, misrepresentation, breach or inducement of a breach of a confidential relationship or other duty to maintain secrecy or limit use, or espionage through electronic or other meansIn force
Reverse engineering or independent development shall not be considered improper means. (b) "Misappropriation" means: (1) acquisition of a trade secret of a person by another person who knows or has reason to know that the trade secret was acquired by improper means; or (2) disclosure or use of a trade secret of a person without express or implied consent by another person who: (A) used improper means to acquire knowledge of the trade secret; or (B) at the time of disclosure or use, knew or had reason to know that knowledge of the trade secret was: (I) derived from or through a person who utilized improper means to acquire it; (II) acquired under circumstances giving rise to a duty to maintain its secrecy or limit its use; or (III) derived from or through a person who owed a duty to the person seeking relief to maintain its secrecy or limit its use; or (C) before a material change of position, knew or had reason to know that it was a trade secret and that knowledge of it had been acquired by accident or mistake.
Official text (excerpt) · last checked 2026-07-29 · Read the full text in our law library · Verify at ilga.gov
Cited in 137 court opinions in our collectionLatest citing opinion in our collection: 2026
Opinions citing this section in our collection:
- Alpha School Bus Co., Inc. v. Wagner (Appellate Court of Illinois 2009, 391 Ill. App. 3d 722)“…circumstances to maintain its secrecy or confidentiality.” 765 ILCS 1065/2(d) (West 2006). In addition, sec…”
- Liebert Corp. v. Mazur (Appellate Court of Illinois 2005, 357 Ill. App. 3d 265)“…circumstances to maintain its secrecy or confidentiality." 765 ILCS 1065/2(d) (West 2002). In other words, plain…”
- Stenstrom Petroleum Services Group Inc. v. Mesch (Appellate Court of Illinois 2007, 375 Ill. App. 3d 1077)“…circumstances to maintain its secrecy or confidentiality.” 765 ILCS 1065/2(d) (West 2004). Thus, a plaintif…”
Identified automatically from the court opinions citing this section — not a ranking of which case controls.
§ 4(a) In addition to the relief provided for by Section 3, a person is entitled to recover damages for misappropriationIn force
Damages can include both the actual loss caused by misappropriation and the unjust enrichment caused by misappropriation that is not taken into account in computing actual loss. If neither damages nor unjust enrichment caused by the misappropriation are proved by a preponderance of the evidence, the court may award damages caused by misappropriation measured in terms of a reasonable royalty for a misappropriator's unauthorized disclosure or use of a trade secret. (b) If willful and malicious misappropriation exists, the court may award exemplary damages in an amount not exceeding twice any award made under subsection (a).
Official text (excerpt) · last checked 2026-07-29 · Read the full text in our law library · Verify at ilga.gov
Cited in 24 court opinions in our collectionLatest citing opinion in our collection: 2023
Opinions citing this section in our collection:
- Alpha School Bus Co., Inc. v. Wagner (Appellate Court of Illinois 2009, 391 Ill. App. 3d 722)“…cover damages for the misappropriation of a “trade secret.” 765 ILCS 1065/4 (West 2006). A “trade secret” is define…”
- McDonald's Corp. v. American Motorists Insurance (Appellate Court of Illinois 2001, 321 Ill. App. 3d 972)“…endants, exemplary damages, and attorneys’ fees pursuant to 765 ILCS 1065/4—5. 63. Additionally, [pjlaintiff…”
- Salsitz v. Kreiss (Appellate Court of Illinois 2000, 311 Ill. App. 3d 590)“…or plaintiffs’ violation of the Illinois Trade Secrets Act (765 ILCS 1065/4(a) et seq. (West 1992)); damages for to…”
Identified automatically from the court opinions citing this section — not a ranking of which case controls.
§ 7An action for misappropriation must be brought within 5 years after the misappropriation is discovered or by the exercise of reasonable diligence should have been discoveredIn force
For the purposes of this Act, a continuing misappropriation constitutes a single claim.
Official text (excerpt) · last checked 2026-07-29 · Read the full text in our law library · Verify at ilga.gov
Cited in 3 court opinions in our collectionLatest citing opinion in our collection: 2020
Opinions citing this section in our collection:
- Maxtech Consumer Products, Ltd. v. Robert Bosch Tool Corp. (District Court, N.D. Illinois 2017, 255 F. Supp. 3d 833)“…rcise of reasonable diligence should have been discovered.” 765 ILCS 1065/7; see also Research Res., Inc. v. Daw…”
- Chartwell Studio, Inc. v. Team Impressions, Inc. (District Court, N.D. Illinois 2020)“…rcise of reasonable diligence should have been discovered. 765 ILCS 1065/7. See also Maxtech Consumer Prod., Ltd. v…”
- Mighty Deer Lick, Inc. v. Morton Salt, Inc. (District Court, N.D. Illinois 2020)“…36(d); Count V (ITSA): 5 years, 765 ILCS 1065/7; Count…”
Identified automatically from the court opinions citing this section — not a ranking of which case controls.
§ 8(a) Except as provided in subsection (b), this Act is intended to displace conflicting tort, restitutionary, unfair competition, and other laws of this State providing civil remedies for misappropriation of a trade secretIn force
(b) This Act does not affect: (1) contractual remedies, whether or not based upon misappropriation of a trade secret, provided however, that a contractual or other duty to maintain secrecy or limit use of a trade secret shall not be deemed to be void or unenforceable solely for lack of durational or geographical limitation on the duty; (2) other civil remedies that are not based upon misappropriation of a trade secret; (3) criminal remedies, whether or not based upon misappropriation of a trade secret; or (4) the definition of a trade secret contained in any other Act of this State.
Official text (excerpt) · last checked 2026-07-29 · Read the full text in our law library · Verify at ilga.gov
Cited in 61 court opinions in our collectionLatest citing opinion in our collection: 2026
Opinions citing this section in our collection:
- Alpha School Bus Co., Inc. v. Wagner (Appellate Court of Illinois 2009, 391 Ill. App. 3d 722)“…t are not based upon misappropriation of a trade secret!.]” 765 ILCS 1065/8 (West 2006). Plaintiffs first ch…”
- Abbott-Interfast Corp. v. Harkabus (Appellate Court of Illinois 1993, 250 Ill. App. 3d 13)“…ack of durational or geographical limitation on the duty.” (765 ILCS 1065/8(b)(l) (West 1992).) Therefore, we canno…”
- Delta Medical Systems v. Mid-America Medical Systems, Inc. (Appellate Court of Illinois 2002)“…on of Delta’s trade secrets, they are preempted by the Act. 765 ILCS 1065/8 (West 2000). To state a cause of…”
Identified automatically from the court opinions citing this section — not a ranking of which case controls.
United States Code Title 18
§ 1836Civil proceedingsIn forcecited in 56 of our articles
The Attorney General may, in a civil action, obtain appropriate injunctive relief against any violation of this chapter. An owner of a trade secret that is misappropriated may bring a civil action under this subsection if the trade secret is related to a product or service used in, or intended for use in, interstate or foreign commerce. Based on an affidavit or verified complaint satisfying the requirements of this paragraph, the court may, upon ex parte application but only in extraordinary circumstances, issue an order providing for the seizure of property necessary to prevent the propagation or dissemination of the trade secret that is the subject of the action.
Official text (excerpt) · last checked 2026-09-08 · Read the full text in our law library · Verify at uscode.house.gov
Cited in 1,770 court opinions in our collectionLatest citing opinion in our collection: 2026
In the courts (editorial summary, independently checked):First Western Capital Management Co. v. Malamed (2017) held Section 1836(b)(3)(A) authorizes but does not mandate an injunction, so irreparable harm cannot be presumed. Syntel v. TriZetto (2023) vacated an avoided-costs award, holding unjust enrichment was unavailable where actual loss already captured the gain.
Opinions citing this section in our collection:
- Oakwood Laboratories LLC v. Bagavathikanun Thanoo (Court of Appeals for the Third Circuit 2021, 999 F.3d 892)✓A drug developer alleged a departing scientist took its microsphere manufacturing processes to a competitor; the Third Circuit vacated dismissal, holding the Section 1836(b) claim was pled adequately and that lost exclusivity is harm even before a rival product launches.
- First Western Capital Management Co. v. Malamed (Court of Appeals for the Tenth Circuit 2017, 874 F.3d 1136)✓A wealth manager won an injunction stopping a fired executive from soliciting clients without proving irreparable harm; the Tenth Circuit held Section 1836(b)(3)(A) authorizes but does not mandate injunctions, so irreparable harm cannot be presumed, and reversed.
- DTC Energy Grp., Inc. v. Hirschfeld (Court of Appeals for the Tenth Circuit 2018, 912 F.3d 1263)✓An oil and gas staffing firm sought to enjoin a former manager who diverted contracts to a rival; the Tenth Circuit affirmed the denial, holding Section 1836(b)(3)(A) allows no presumption of irreparable harm and finding no proof the defendants still held the trade secrets.
Identified automatically from the court opinions citing this section — not a ranking of which case controls.
Also relied on in: Trade Secret Laws by State: UTSA & DTSA (2026), Alabama Trade Secret Laws: UTSA, Remedies & Deadlines, Alaska Trade Secret Laws: UTSA, Remedies & Deadlines
§ 1832Theft of trade secretsIn forcecited in 29 of our articles
Whoever, with intent to convert a trade secret, that is related to a product or service used in or intended for use in interstate or foreign commerce, to the economic benefit of anyone other than the owner thereof, and intending or knowing that the offense will, injure any owner of that trade secret, knowingly— steals, or without authorization appropriates, takes, carries away, or conceals, or by fraud, artifice, or deception obtains such information; without authorization copies, duplicates, sketches, draws, photographs, downloads, uploads, alters, destroys, photocopies, replicates, transmits, delivers, sends, mails, communicates, or conveys such information; receives, buys, or possesses such information, knowing the same to have been stolen or appropriated, obtained, or converted without authorization; attempts to commit any offense described in paragraphs (1) through (3); or conspires with one or more other persons to commit any offense described in paragraphs (1) through (3), and one or more of such persons do any act to effect the object of the conspiracy, shall, except as provided in subsection (b), be fined under this title or imprisoned not more than 10 years, or both.
Official text (excerpt) · last checked 2026-07-28 · Read the full text in our law library · Verify at uscode.house.gov
Cited in 260 court opinions in our collectionLatest citing opinion in our collection: 2026
Opinions citing this section in our collection:
- United States v. Nosal (Court of Appeals for the Ninth Circuit 2012, 676 F.3d 854)“…Congress did just that in the federal trade secrets statute—18 U.S.C. § 1832—where it used the common law terms for…”
- United States v. Kai-Lo Hsu, A/K/A James Hsu. United States of America v. Chester S. Ho. United States of America (Court of Appeals for the Third Circuit 1998, 155 F.3d 189)“…and a conspiracy to steal trade secrets, in violation of 18 U.S.C. §§ 1832 (a)(4) and (a)(5). B. The…”
- United States v. Martin (Court of Appeals for the First Circuit 2000, 228 F.3d 1)“…16- Espionage Act of 1996, specifically 18 U.S.C. § 1832(a)(5).6 In order to find a defendant g…”
Identified automatically from the court opinions citing this section — not a ranking of which case controls.
Also relied on in: Arizona Trade Secret Laws: UTSA, Remedies & Deadlines, Florida Trade Secret Laws: UTSA, Remedies & Deadlines, Georgia Trade Secret Laws: UTSA, Remedies & Deadlines
§ 1838Construction with other lawsIn forcecited in 56 of our articles
Except as provided in section 1833(b), this chapter shall not be construed to preempt or displace any other remedies, whether civil or criminal, provided by United States Federal, State, commonwealth, possession, or territory law for the misappropriation of a trade secret, or to affect the otherwise lawful disclosure of information by any Government employee under section 552 of title 5 (commonly known as the Freedom of Information Act).
Official text (excerpt) · last checked 2026-07-28 · Read the full text in our law library · Verify at uscode.house.gov
Cited in 10 court opinions in our collectionLatest citing opinion in our collection: 2026
In the courts (editorial summary, independently checked):Courts cite 18 U.S.C. 1838 to note that the Defend Trade Secrets Act does not displace state trade secret remedies. Syntel Sterling Best Shores Mauritius, Ltd. v. the TriZetto Grp. (2023) said so while drawing on state UTSA cases for DTSA damages; Quintara Biosciences, Inc. v. Ruifeng Biztech, Inc. (2025) cited it for parallel claims.
Opinions citing this section in our collection:
- Syntel Sterling Best Shores Mauritius, Ltd. v. the TriZetto Grp. (Court of Appeals for the Second Circuit 2023, 68 F.4th 792)✓Reviewing a $285 million DTSA award for misappropriated software trade secrets, the Second Circuit cited section 1838 for the point that the DTSA does not preempt state trade secret remedies, and so read the federal damages provision alongside state UTSA cases.
- Authority to Obtain and Share Statewide Voter Roll Data (Department of Justice Office of Legal Counsel 2026)“…luded a saving provision for state privacy laws, see, e.g., 18 U.S.C. § 1838; 42 U.S.C. § 300jj-19(c)(4), “Congress…”
- Quintara Biosciences, Inc. v. Ruifeng Biztech, Inc. (Court of Appeals for the Ninth Circuit 2025)“…tate and federal trade- secret-misappropriation claims. See 18 U.S.C. § 1838 (providing that DTSA “shall not be cons…”
Identified automatically from the court opinions citing this section — not a ranking of which case controls.
Also relied on in: Arkansas Trade Secret Laws: UTSA, Remedies & Deadlines, California Trade Secret Laws: UTSA, Remedies & Deadlines, Colorado Trade Secret Laws: UTSA, Remedies & Deadlines
Sources and References
- Illinois Trade Secrets Act, 765 ILCS 1065/1 to 1065/9(ilga.gov).gov
- Defend Trade Secrets Act, 18 U.S.C. §§ 1836-1839(law.cornell.edu)
- Uniform Trade Secrets Act (Uniform Law Commission)(uniformlaws.org)
- Economic Espionage Act, 18 U.S.C. §§ 1831-1832(law.cornell.edu)
- 765 ILCS 1065/2, trade-secret definitions(www.ilga.gov).gov
- 765 ILCS 1065/5, attorney fees(www.ilga.gov).gov