Invention Assignment Laws in Illinois: Who Owns What You Create

Federal law does not directly regulate invention ownership between employers and employees. Instead, the framework relies on state law and contractual agreements. The federal Uniform Trade Secrets Act (18 U.S.C. § 1836) protects trade secrets and confidential business information, including employee inventions, from misappropriation. Title 35 of the U.S. Code (Patent Law) establishes that inventors are entitled to patent protection, but employment contracts can transfer patent rights if properly executed. The federal Trade Secrets Act applies to the theft or misuse of trade secrets, not the initial allocation of ownership.

Federally, the principle is that absent a written agreement, inventions made by an employee belong to the employee, even if made during employment. However, employers can protect their interests through properly drafted non-compete and invention assignment agreements, provided they meet reasonableness standards. The federal baseline is limited; states like Illinois supplement with specific statutory frameworks addressing reasonableness, scope, and enforceability of restrictive covenants.

The EEOC does not have jurisdiction over invention ownership disputes. Patent disputes may be addressed through the U.S. Patent and Trademark Office (USPTO) or federal courts if patent rights are at issue.

Illinois imposes significant limits on invention assignment through two primary statutes: the Illinois Uniform Trade Secrets Act (765 ILCS 1065/1 et seq.) and the Illinois Restrictive Covenant Enforcement Act (740 ILCS 140/1 et seq.). Under Illinois law, an employer can claim ownership of an invention only if all of the following conditions are met: (1) the invention was developed entirely on the employer's time or using the employer's equipment, facilities, or materials; (2) the invention relates to the employer's business or actual or demonstrably anticipated research or development; or (3) the invention results from work performed for the employer.

Illinois is stricter than federal baseline in several ways. The state requires that non-compete and invention assignment agreements meet the "blue pencil" standard—they must be reasonable in scope, duration, and geographic area to be enforceable. Overbroad provisions are struck down or reformed by courts. Illinois also protects employees who develop inventions on personal time using personal resources; employers cannot claim ownership even if the employee is an engineer or scientist in a related field. The statute explicitly states that a provision requiring an employee to assign inventions unrelated to the employer's business or developed entirely on the employee's own time is void.

Employers covered under Illinois law include all private employers, public employers, and governmental entities. However, the law distinguishes between employees and independent contractors. The Illinois Uniform Trade Secrets Act (765 ILCS 1065) applies to trade secrets and confidential information, defining protected material and remedies for misappropriation. Under this statute, employees retain stronger protections than federal law provides—Illinois courts have consistently ruled that assignment clauses must be supported by consideration and cannot be unilateral or unconscionable.

Unique to Illinois is the "California rule" influence: Illinois courts apply a reasonableness test similar to California's, examining whether the restriction is necessary to protect legitimate business interests. The state also recognizes the doctrine of inevitable disclosure but applies it narrowly, requiring proof that the employee will inevitably rely on trade secrets in the new role. Remedies under Illinois law include injunctive relief, damages for misappropriation, attorney's fees in trade secret cases, and reformation of overly broad contracts by courts. The Illinois Uniform Trade Secrets Act also provides a private right of action against those who steal or misappropriate trade secrets (765 ILCS 1065/3).

Illinois law provides several important exceptions to employer ownership of inventions. The most critical exception is the personal time rule: inventions developed entirely on your own time, outside working hours, and without using any company resources are your property exclusively. This applies even if you work in a field directly related to the employer's business.

Another exception applies to inventions unrelated to the employer's business or anticipated research and development. For example, if you work as an accountant and develop a mechanical device in your home workshop, the employer has no ownership claim even if you signed a broad assignment agreement. Illinois courts have consistently voided provisions that attempt to claim ownership of such inventions.

The reasonableness exception is critical: overly broad assignment clauses are unenforceable or subject to reformation. If a clause attempts to claim all inventions "in any way related to the company's field of endeavor," Illinois courts will narrow it to only those inventions actually developed using company resources or directly related to the company's current or demonstrably anticipated business. Courts also scrutinize the enforceability of non-compete and invention assignment agreements under the Restrictive Covenant Enforcement Act (740 ILCS 140), which requires that they be no broader than reasonably necessary to protect legitimate business interests.

The lack-of-consideration exception applies when an employee signs an invention assignment agreement after starting employment without receiving new consideration (such as a promotion, raise, or continued employment beyond an initial contract). Illinois courts may refuse to enforce such agreements, though courts have upheld them when employment itself constitutes consideration during the initial hire.

Trade secret protection limitations also apply: if information is not genuinely a trade secret (it is widely known or easily discoverable), the employer cannot restrict its use or claim ownership based on confidentiality. Additionally, the Illinois Uniform Trade Secrets Act does not protect information that is independently developed or lawfully obtained from other sources.

Step 1: Document Everything. Keep detailed records of when and where you developed the invention. Photograph or record your work on personal time, save emails or communications showing the development occurred outside working hours, preserve receipts for personal equipment or materials purchased with your own money, and document any communications with your employer regarding the invention. Save any work samples, prototypes, designs, or code versions with timestamps. This documentation is critical if you later need to prove the invention was developed on your own time or with personal resources.

Step 2: Review Your Employment Contract and Challenge the Clause. Obtain a copy of your employment agreement, offer letter, non-compete agreement, and any other documents signed when hired or during employment. Identify the specific invention assignment language. Analyze whether the clause is overly broad by checking if it claims ownership of inventions developed entirely on your own time, unrelated to the company's business, or created without using company resources. Consult an employment attorney to assess whether the clause meets the Illinois reasonableness standard. If the clause appears unenforceable, consider sending a formal written response to your employer stating your position that the invention is your property and not subject to the agreement.

Step 3: Attempt Internal Resolution. Communicate with your manager or human resources department in writing (email is best for documentation). Explain that you developed the invention on personal time using personal resources and that it does not fall within the scope of any valid assignment agreement. Request written confirmation that the company does not claim ownership. If the company disputes your position, ask for their written legal justification. Request a meeting with HR or legal counsel to discuss the matter. This internal process creates a record and may resolve the dispute without litigation.

Step 4: File a Misappropriation Claim if Necessary. If the company claims ownership, uses your invention without permission, or attempts to patent or commercialize your invention, you can file a misappropriation claim under the Illinois Uniform Trade Secrets Act (765 ILCS 1065). Before filing suit, send a cease and desist letter through an attorney documenting the misappropriation and demanding that the company stop using the invention and acknowledge your ownership. If the company ignores the demand, file a civil action in Illinois state court (or federal court if diversity jurisdiction applies). The action must be brought within 3 years of discovering the misappropriation. Include claims for injunctive relief (to stop the company's use), damages for actual loss, reasonable attorney's fees, and enhanced damages if misappropriation was willful and malicious.

Step 5: Consult an Employment Law Attorney. Contact an Illinois employment law attorney who specializes in intellectual property and restrictive covenants if you believe your invention assignment agreement is unenforceable, if your employer has claimed ownership improperly, or if you are considering developing and commercializing the invention independently. An attorney can: review your contract for unenforceable provisions, assess your documentation, evaluate the strength of your ownership claim, file a declaratory judgment action seeking a court declaration that the invention is your property, and represent you in negotiations or litigation. Given the technical and legal complexity, early consultation is strongly advised—waiting can weaken your position if the employer files a patent or begins using the invention.