Can an Illinois employer require assignment of every invention?
No. The Illinois Employee Patent Act, 765 ILCS 1060/2, carves out a category of inventions that an assignment clause simply cannot reach: anything the employee developed entirely on their own time, without the employer's equipment, supplies, facilities, or trade-secret information, that neither relates to the employer's business or actual or demonstrably anticipated research or development nor results from the employee's work. To the extent a clause purports to capture those own-time inventions, it is against the public policy of the state and void — and the employee bears the burden of proving that the invention qualifies.
Subsection (1) frames the carve-out as a limit on what an assignment promise can do. However broadly the contract is written, it does not reach an invention the employee made on their own time and with their own resources unless one of two statutory exceptions applies .
The same subsection supplies the teeth: a provision that tries to require assignment of an invention the statute excludes is not merely unenforceable as written but declared against public policy .
The allocation of proof, however, runs against the employee. When a dispute arises, the employee who wants the benefit of the own-time carve-out must establish that the invention qualifies — the statute places that burden on the employee, not the employer .
Subsection (2) closes the obvious workaround. An employer cannot demand the void assignment anyway by making the employee sign it to keep the job — a provision made void and unenforceable by subsection (1) may not be required as a condition of employment or continuing employment .
Sources for this answer
Primary law
A.1 765 ILCS 1060/2Section 2(1) of the Illinois Employee Patent Act makes an assignment clause inapplicable to an invention the employee developed entirely on their own time without the employer's equipment, supplies, facilities, or trade-secret information, unless the invention relates to the employer's business or actual or demonstrably anticipated research or development, or results from the employee's work; any provision purporting to reach such an invention is against the public policy of the state and void and unenforceable to that extent.
A provision in an employment agreement which provides that an employee shall assign or offer to assign any of the employee's rights in an invention to the employer does not apply to an invention for which no equipment, supplies, facilities, or trade secret information of the employer was used and which was developed entirely on the employee's own time, unless (a) the invention relates (i) to the business of the employer, or (ii) to the employer's actual or demonstrably anticipated research or development, or (b) the invention results from any work performed by the employee for the employer. Any provision which purports to apply to such an invention is to that extent against the public policy of this State and is to that extent void and unenforceable.
See 765 ILCS 1060/2(1).
Primary law
A.2 765 ILCS 1060/2Section 2(1) places the burden of proof on the employee to establish that the invention qualifies for the own-time carve-out.
The employee shall bear the burden of proof in establishing that his invention qualifies under this subsection.
See 765 ILCS 1060/2(1).
Primary law
A.3 765 ILCS 1060/2Section 2(2) bars an employer from requiring a provision made void and unenforceable by subsection (1) as a condition of employment or continuing employment.
An employer shall not require a provision made void and unenforceable by subsection (1) of this Section as a condition of employment or continuing employment.
See 765 ILCS 1060/2(2).
Must an Illinois employer notify the employee?
Yes. Section 2(3) requires an employer whose agreement contains an invention-assignment provision to give the employee, at the time the agreement is made, a written notification that the agreement does not apply to a qualifying own-time, own-resource invention. The statute does not say what happens if the employer omits that notice, and no Illinois case in our review decides whether a missing notice voids an otherwise valid clause — so the cautious course is to treat the notice as mandatory.
The notice obligation is contemporaneous, not eventual: the written notification must accompany the agreement when it is made, for any agreement entered into after January 1, 1984. It does not change which inventions are carved out — subsection (1) does that — but it ensures the employee is told the carve-out exists .
Because no Illinois decision in our review resolves the consequence of skipping the notice, a drafter should not gamble on the omission being harmless. The statute's text makes the notice a requirement, and pairing an assignment clause with the section 2(3) notification at signing removes any doubt.
Sources for this answer
Primary law
B.1 765 ILCS 1060/2Section 2(3) requires an employer whose agreement contains an assignment provision to give the employee, at the time the agreement is made, a written notification that the agreement does not apply to a qualifying own-time, own-resource invention.
If an employment agreement entered into after January 1, 1984, contains a provision requiring the employee to assign any of the employee's rights in any invention to the employer, the employer must also, at the time the agreement is made, provide a written notification to the employee that the agreement does not apply to an invention for which no equipment, supplies, facility, or trade secret information of the employer was used and which was developed entirely on the employee's own time
See 765 ILCS 1060/2(3).
Who owns an invention by default in Illinois?
The inventor. Absent a written assignment, the baseline rule under federal patent law — which governs who holds title to a patentable invention in Illinois as elsewhere — is that rights belong to the employee who conceived it. The U.S. Supreme Court restated that premise in Stanford v. Roche, and although others may acquire an interest, that interest must trace back to the inventor. Illinois's Employee Patent Act expressly preserves an employer's common-law shop rights against employees who never signed an agreement, and the hired-to-invent doctrine can give an employer title where the employee was engaged specifically to invent — but a written present-assignment clause remains the dependable route to ownership.
Stanford v. Roche anchors the default. The Court held that the Bayh-Dole Act did not displace the long-standing rule that an invention belongs to its inventor, treating that premise as the baseline against which any assignment must be measured .
Because ownership starts with the inventor, an employer's title is derivative: it exists only if and to the extent the employee assigned it. Any third-party interest in the invention must trace back to that inventor-grantor .
Illinois preserves one narrow overlay for the employee who never signed anything. Section 2(2) states that the Act does not preempt existing common law applicable to shop rights — the employer's non-exclusive, royalty-free license to use an invention its resources helped produce — for employees who never signed an employment agreement .
The other non-contractual route is the hired-to-invent doctrine. As the U.S. Supreme Court explained in United States v. Dubilier Condenser Corp., an employee engaged specifically to make an invention who accomplishes that task must assign the resulting patent, because the invention is the very thing the employee was hired to produce. But that doctrine is fact-intensive and confined to employees actually hired for inventive work, so an Illinois employer that wants dependable title relies instead on a written present-assignment (hereby assigns) clause — present-tense language that transfers legal title automatically on conception, rather than a future promise to assign — operating within the boundaries section 2 imposes .
Sources for this answer
Case law · 2011-06-06
C.1 Bd. of Trustees of the Leland Stanford Junior Univ. v. Roche Molecular SystemsStanford v. Roche confirms the long-standing premise of U.S. patent law that rights in an invention belong to the inventor.
Since 1790, the patent law has operated on the premise that rights in an invention belong to the inventor.
See Bd. of Trustees of the Leland Stanford Junior Univ. v. Roche Molecular Sys., Inc., 563 U.S. 776 (2011).
Case law · 2011-06-06
C.2 Bd. of Trustees of the Leland Stanford Junior Univ. v. Roche Molecular SystemsStanford v. Roche holds that although others may acquire an interest in an invention, that interest as a general rule must trace back to the inventor — so an employer takes title only through an assignment from the employee-inventor.
Thus, although others may acquire an interest in an invention, any such interest — as a general rule — must trace back to the inventor.
See Bd. of Trustees of the Leland Stanford Junior Univ. v. Roche Molecular Sys., Inc., 563 U.S. 776 (2011).
Primary law
C.3 765 ILCS 1060/2Section 2(2) provides that the Illinois Employee Patent Act does not preempt existing common law applicable to an employer's shop rights with respect to employees who have not signed an employment agreement.
This Act shall not preempt existing common law applicable to any shop rights of employers with respect to employees who have not signed an employment agreement.
See 765 ILCS 1060/2(2).
Case law · 1933-05-08
C.4 United States v. Dubilier Condenser Corp.United States v. Dubilier Condenser Corp. states the hired-to-invent doctrine: an employee engaged specifically to make an invention who accomplishes that task is bound to assign any resulting patent to the employer, because the invention is the precise subject of the employment.
One employed to make an invention, who succeeds, during his term of service, in accomplishing that task, is bound to assign to his employer any patent obtained. The reason is that he has only produced that which he was employed to invent. His invention is the precise subject to the contract of employment.
See United States v. Dubilier Condenser Corp., 289 U.S. 178 (1933).
Are trailing-assignment (holdover) clauses enforceable in Illinois?
Only so far as they are reasonable. Illinois has no statute that caps a post-employment trailing-assignment (holdover) clause, so its enforceability is governed by the general public-policy limits on invention-assignment covenants. The Seventh Circuit's decision in Guth v. Minnesota Mining & Manufacturing Co. is the leading statement of those limits: a provision that is limitless in time and in subject matter is contrary to public policy, but a court will enforce the covenants that are reasonable and sever those that are not.
The starting point is that an employer may contract for its employees' inventions, but only within limits. Guth recognized the employer's right to secure patentable discoveries by contract while making clear that the right is bounded .
Where a clause exceeds those limits, it falls. The Guth court held that provisions reaching an unlimited span of time and any subject matter of invention — the classic overbroad holdover tail — are contrary to public policy, because such a covenant would effectively close the doors of future employment to the worker .
But the court did not throw out the whole agreement. It treated the contract as divisible and enforced the covenants that were reasonable while refusing the ones that were not — the same reasonableness-and-severance approach Illinois applies to restrictive covenants generally .
Two caveats keep this from being a settled rule. Guth is a Seventh Circuit decision applying general public-policy principles rather than a modern Illinois Supreme Court holding squarely on post-employment trailing assignments, and we found no Illinois decision in our review that fixes a bright-line durational or subject-matter ceiling. A drafter should therefore treat reasonableness in time and scope as the operative constraint and avoid a limitless trailing tail, which Guth indicates a court would refuse to enforce as written.
Sources for this answer
Case law · 1934-07-30
D.3 Guth v. Minnesota Mining & Mfg. Co.Guth recognizes that an employer may contract for its employees' patentable discoveries, but only within certain limits.
The right of an employer to contract for patentable discoveries made by its employee within certain limits is well recognized.
See Guth v. Minnesota Mining & Mfg. Co., 72 F.2d 385 (7th Cir. 1934).
Case law · 1934-07-30
D.1 Guth v. Minnesota Mining & Mfg. Co.Guth holds that invention-assignment provisions limitless in extent of time and in subject matter of invention are contrary to public policy.
those provisions of the contract which were limitless in extent of time and in subject matter of invention were contrary to public policy.
See Guth v. Minnesota Mining & Mfg. Co., 72 F.2d 385 (7th Cir. 1934).
Case law · 1934-07-30
D.2 Guth v. Minnesota Mining & Mfg. Co.Guth treats the invention-assignment contract as divisible: the covenants contrary to public policy are unenforceable while the reasonable covenants remain valid and enforceable in equity.
Some of the covenants are contrary to public policy and non-enforceable. Others are valid and enforceable in a court of equity (although courts are not required in all cases to grant the specific performance of such contracts).
See Guth v. Minnesota Mining & Mfg. Co., 72 F.2d 385 (7th Cir. 1934).
Do not paper an Illinois employee with an out-of-state invention-assignment form. A form built for an assign-everything jurisdiction will usually omit the section 2(3) written notice of the own-time carve-out, and it often contains an aggressive post-employment trailing-assignment (holdover) clause that reaches inventions limitless in time and subject matter — the kind Guth holds contrary to public policy. Confirm the agreement carries the section 2(3) notice at signing, limit the assignment to the categories section 2 actually allows, and pare any holdover tail back to a reasonable time and scope rather than relying on a limitless one.