Inventorship and Patent Ownership Disputes Toolkit

By Casey Scott McKay · 2024-02-21

Inventorship is the most consequential determination in patent practice that is routinely made by administrative default, and the consequences of getting it wrong reach ownership, standing, and the ability to enforce at all. This toolkit works conception as the touchstone, the claim-by-claim analysis inventorship actually requires, and the Pannu factors for joint inventorship. It sets out the ownership default - inventors own, assignments must be in writing, and a co-owner may license the accused infringer without accounting - and the assignment drafting that Stanford v. Roche and its successors make essential. It covers correction under Section 256, derivation proceedings, standing problems, and the evidence that decides disputes: notebooks, records, and contemporaneous documentation.

IP and Technology > Patent Counseling Transactions | Toolkit | Published 21 February 2024 - Updated 18 March 2025 | Casey Scott McKay - marksy.us

Summary. Inventorship is the most consequential determination in patent practice that is routinely made by administrative default, and the consequences of getting it wrong reach ownership, standing, and the ability to enforce at all. This toolkit works conception as the touchstone, the claim-by-claim analysis inventorship actually requires, and the Pannu factors for joint inventorship. It sets out the ownership default — inventors own, assignments must be in writing, and a co-owner may license the accused infringer without accounting — and the assignment drafting that Stanford v. Roche and its successors make essential. It covers correction under Section 256, derivation proceedings, standing problems, and the evidence that decides disputes: notebooks, records, and contemporaneous documentation.

Keywords: inventorship · conception · joint inventorship · Pannu factors · Burroughs Wellcome · claim by claim analysis · correction under section 256 · ownership default · section 261 assignment · present assignment language · Stanford v Roche · FilmTec · Omni MedSci · co-owner licensing · Ethicon v US Surgical · standing to sue · derivation proceedings · employee invention agreements · joint development background IP · laboratory notebooks

Start Here

A company prepares to assert a patent. The defendant's answer includes a paragraph nobody expected: it has taken a licence from a former employee of the plaintiff, who it says is an unnamed co-inventor of the asserted patent.

If that is right, the case is over. Not weakened — over. A patent co-owner may license anyone, without the consent of the other owners and without any duty to account for what it receives. The defendant now has a licence to the patent being asserted against it.

That result follows from two rules that are individually unremarkable and jointly devastating. Inventorship is determined by who conceived the subject matter of the claims, not by who was on the project. And ownership follows inventorship unless a written assignment says otherwise.

This toolkit answers three questions.

Who is an inventor? Conception of the subject matter of at least one claim, assessed claim by claim.
Who owns it? The inventors, until a written assignment transfers it — and the assignment language matters more than anyone expects.
What happens when it is wrong? Correction is usually available; the ownership consequences of correction frequently are not.

If you read only one thing, read Who Actually Invented It. It works conception, the claim-by-claim requirement, and why the error is more common than practitioners believe.

Conception

The definition. Burroughs Wellcome v. Barr Laboratories defines conception as the formation in the mind of the inventor of a definite and permanent idea of the complete and operative invention, as it is thereafter to be applied in practice.

Definite and permanent. The idea must be sufficiently specific that a person of ordinary skill could reduce it to practice without extensive research or experimentation. A general goal or a research plan is not conception.

It is a mental act. Conception is complete when the idea is formed, not when it is built. Reduction to practice, whether actual or constructive through filing, is a separate step.

Corroboration is required. An inventor's testimony alone does not establish conception. Contemporaneous documents, witness testimony, and physical evidence supply the corroboration, assessed under a rule-of-reason approach.

Who is an inventor. 35 U.S.C. § 100 defines the inventor as the individual who invented or discovered the subject matter of the invention. Only natural persons qualify.

What does not make someone an inventor. Suggesting a problem to solve. Providing well-known principles or the state of the art. Reducing another's conception to practice under direction. Supervising. Funding. Building the prototype from someone else's design.

Hess v. Advanced Cardiovascular Systems illustrates the limit: a supplier who provided information about materials that was in the public domain and made suggestions a skilled person would make was not a co-inventor.

The practical consequence. The person who did the most work is frequently not an inventor, and a person who contributed a single conceptual element to a single dependent claim is.

Joint Inventorship

The statute. 35 U.S.C. § 116 permits joint invention, and provides that inventors may apply jointly even though they did not physically work together, each did not make the same type or amount of contribution, and each did not contribute to the subject matter of every claim.

That last clause is the whole problem. A person who contributed to one claim is a joint inventor of the patent, with all the ownership consequences that follow.

Pannu v. Iolab sets out what a joint inventor must show: contribution in some significant manner to conception or reduction to practice, a contribution to the claimed invention that is not insignificant in quality when measured against the dimension of the full invention, and more than merely explaining well-known concepts or the current state of the art.

Collaboration is required. Joint inventors must have some open line of communication or connection. Independent inventors of the same thing are not joint inventors.

The claim-by-claim requirement. Inventorship is determined for each claim, and the named inventors are the union of the inventors of all claims. Amending claims during prosecution can change inventorship, and frequently does without anyone noticing.

Which means inventorship should be revisited at allowance. Claims that issue are rarely the claims that were filed.

Trovan v. Sokymat applies the analysis in a commercial dispute, and illustrates how factual and document-driven it is.

Presumption and burden. Issued patents are presumed to name the correct inventors, and a party alleging otherwise bears a heavy burden — clear and convincing evidence, with corroboration.

The Ownership Default

Inventors own. Absent an assignment, each inventor owns an undivided interest in the entire patent. Not a share proportional to contribution — an undivided interest in the whole.

35 U.S.C. § 262 provides that in the absence of an agreement to the contrary, each joint owner may make, use, offer to sell, sell, or import the patented invention without the consent of and without accounting to the other owners.

Including licensing. Ethicon v. United States Surgical confirms that a co-owner may grant a licence, and that a licence from one co-owner is a complete defence to infringement. In that case an omitted inventor's retroactive licence to the accused infringer defeated the suit.

Standing. All co-owners must generally join an infringement action, and a co-owner who refuses cannot ordinarily be compelled. One unwilling co-owner ends the case.

Assignments require a writing. 35 U.S.C. § 261 provides that patents and applications are assignable by an instrument in writing.

Recordation. 35 U.S.C. § 261 also provides that an assignment is void against a subsequent purchaser for value without notice unless recorded within the prescribed period, and 37 C.F.R. § 3.11 governs recordation practice.

Establishing the right of an assignee to take action in the Office is governed by 37 C.F.R. § 3.73.

The consequence of the default. A company that employs inventors but has no written assignment does not own its patents. That is a more common finding than it should be, particularly for founders, consultants, and academic collaborators.

Assignment Language, Which Decides Cases

The distinction. "Hereby assigns" effects a present transfer of future rights. "Agrees to assign" is a promise to assign in the future, which creates only an equitable interest until a further instrument executes.

FilmTec v. Allied-Signal established that a present assignment of a future invention automatically vests legal title when the invention comes into being, without any further act.

Board of Trustees of the Leland Stanford Junior University v. Roche Molecular Systems applied the distinction with severe consequences: an inventor's later present assignment to a company defeated an earlier promise to assign to the university, and the Supreme Court confirmed that Bayh-Dole does not itself vest title in a contractor.

Omni MedSci v. Apple held that a university policy stating that patents "shall be the property of" the university was not a present automatic assignment, and therefore did not transfer title.

Which means the words matter enormously. A policy, a handbook, or an agreement using "shall be the property of" or "agrees to assign" may not have transferred anything.

Drafting rule. Use "hereby assigns and transfers" with a present-tense grant covering inventions made during employment and within the scope. Add a further-assurances covenant and a power of attorney for execution of confirmatory documents.

State law constrains employee assignment agreements. Several states limit the reach of invention assignment provisions, excluding inventions developed entirely on the employee's own time without employer resources and unrelated to the employer's business, and requiring written notice of the limitation.

Contractors are the recurring gap. There is no work-made-for-hire doctrine for patents. A contractor who invents owns the invention absent a written assignment, whatever the services agreement says about deliverables.

The Evidence That Decides Disputes

Inventorship is a factual question resolved on documents, and the documents either exist or they do not.

Laboratory notebooks. Dated, bound or otherwise tamper-evident, signed by the recorder, and witnessed by someone who understood the content. Witnessing is what supplies corroboration.

Invention disclosure forms. Completed at the time, identifying contributors and describing the conception. These are frequently privileged where submitted for legal advice under In re Spalding Sports Worldwide, which does not make them useless as internal records.

Design and engineering records. Version histories, design reviews, and change logs establish who introduced what and when.

Email and messages. Contemporaneous discussion of the idea, which is frequently the best corroboration available in modern practice because nobody keeps notebooks.

Meeting records. Attendance lists and minutes for the meetings at which the invention was discussed.

Prototypes and test data. Physical evidence of reduction to practice, though reduction to practice does not itself establish conception.

Third-party records. Supplier communications, external testing reports, and collaborator correspondence.

Corroboration under a rule of reason. No single category is required, and the court assesses all the evidence together. The one thing that fails is uncorroborated testimony years later.

What to build. An invention record practice that captures who contributed what, dated and witnessed, at the point of conception. It costs an hour per invention and it is the difference between a defensible determination and a swearing contest.

And keep it. Retention schedules that discard project records after three years destroy the evidence for inventorship disputes that arise ten years later during assertion.

Correction Under Section 256

The mechanism. 35 U.S.C. § 256 permits correction of a patent that names a non-inventor, or omits an inventor, where the error arose without deceptive intention.

Two routes. A petition to the Office where all parties agree and the necessary statements can be obtained, or a district court action where they do not, with the court ordering the Office to issue a certificate.

Deceptive intent. The America Invents Act amendments removed the deceptive intention bar from the operative provision, materially widening availability.

During pendency. 37 C.F.R. § 1.48 governs correction in a pending application, which is far simpler than post-grant correction.

Correction does not fix ownership. Adding an inventor creates a co-owner unless that person assigns. The assignment must be obtained at the same time, and a newly added inventor who understands their position may not be inclined to sign.

Which is why timing matters. Correct while the inventor is employed, cooperative, and unaware of the patent's value. That is not cynicism; it is the practical reality that correction is easy in year one and a negotiation in year eight.

The alternative to correction. Where an omitted inventor cannot be brought in, the patent is vulnerable to an invalidity argument for incorrect inventorship, subject to the correction provision — which is why defendants raise the issue and then oppose correction.

Pannu v. Iolab directs that where a claim of incorrect inventorship is made, the court should consider whether correction is available before invalidating.

Derivation. 35 U.S.C. § 135 provides a derivation proceeding where an applicant alleges that an earlier applicant derived the invention from them. It is narrow, time-limited, and rarely used, but it is the mechanism where the dispute is about who invented rather than who was named.

Standing and Enforcement

The rule. 35 U.S.C. § 281 gives a patentee a civil action for infringement, and "patentee" includes successors in title.

All owners must join. An action brought by fewer than all co-owners is subject to dismissal, and a co-owner cannot ordinarily be involuntarily joined.

Which makes one unwilling co-owner fatal. Ethicon v. United States Surgical is the case that establishes both halves: a co-owner may license the accused infringer, and the licence defeats the suit.

Exclusive licensees. Standing depends on whether substantial rights transferred. Lone Star Silicon Innovations v. Nanya Technology works the analysis: a transferee holding all substantial rights may sue alone; one holding fewer must join the owner.

What courts examine. The right to exclude, the scope of the licence, the right to sublicense, the right to sue and control litigation, the duration, and any retained rights of the licensor.

Nunc pro tunc assignments. An assignment executed after filing, purporting to be retroactive, generally does not cure a standing defect that existed at filing. Standing is assessed at the time the complaint is filed.

Which means chain of title must be complete before filing. Discovering a gap after filing frequently means dismissal and refiling, with the limitations and marking consequences that follow.

Recordation matters for priority. 35 U.S.C. § 261 makes an unrecorded assignment void against a subsequent bona fide purchaser, and 37 C.F.R. § 3.11 governs the mechanics.

Assignor estoppel. An assignor may be estopped from challenging the validity of the assigned patent, though the doctrine has been narrowed and applies only where the assignor's invalidity contention contradicts explicit or implicit representations made in assigning.

The Recurring Gaps

Five situations produce most ownership defects, and each is preventable.

Founders. Inventions conceived before incorporation, or before any assignment was signed, belong to the founder personally. A company formed around a founder's invention should execute a present assignment at formation, covering the pre-formation invention specifically. Investors' counsel will ask for it; better to have it.

Contractors and consultants. There is no work-made-for-hire doctrine for patents. A consultant who invents owns the invention absent a written present assignment, and a services agreement transferring "deliverables" or "work product" may not transfer patent rights to an invention.

Academic collaborators. University policies vary, faculty inventions are frequently subject to institutional assignment obligations, and Board of Trustees of Stanford University v. Roche shows what happens when a promise to assign meets a later present assignment. A company collaborating with a university should confirm the institution's chain and obtain confirmatory assignments.

Joint development partners. Absent agreement, inventions conceived jointly are jointly owned, with each party free to license the other's competitors under 35 U.S.C. § 262. The agreement must allocate foreground ownership expressly. See Structuring a Joint Development Agreement.

Acquired companies and asset purchases. Chains break at acquisitions, particularly where the target itself never obtained assignments. A buyer acquiring patents acquires the defects.

Two further gaps worth naming. Interns and visiting researchers, who are frequently onboarded without the standard agreement. And employees in states whose statutes limit the reach of invention assignment provisions, where the agreement may be partly unenforceable and where written notice of the limitation is required.

The remedy for all of them is the same. Present-tense assignment language, executed before the work begins, with a further-assurances covenant and a power of attorney, recorded with the Office.

Building the Programme

One agreement, used everywhere. Employees, contractors, consultants, interns, and advisers, with the state-law variations built in.

Executed at onboarding. Not at filing, not at a project's start, and never after the invention exists.

A present grant. "Hereby assigns and transfers" covering inventions conceived or reduced to practice during the engagement and within the scope of the work or using company resources.

A further-assurances covenant and a power of attorney so that confirmatory documents can be executed if the inventor is unavailable.

An invention disclosure practice. A standing form capturing the invention, the date of conception, the contributors and what each contributed, the corroborating records, and the project.

An inventorship determination at filing. Claim by claim, against the disclosure and the records, with the reasoning recorded.

A second determination at allowance. Claims change during prosecution, and the inventors of the issued claims may not be the inventors of the filed claims.

Recordation. 37 C.F.R. § 3.11 recordation for every assignment, promptly, with the recordation reference stored against the patent.

An annual audit. Patents with unrecorded or missing assignments, patents whose named inventors have not been verified against records, and departures that removed a potential corroborating witness.

Retention. Keep invention records for the life of the patent plus the limitations period, because the dispute arises during assertion, which is late in the term.

Three Worked Disputes

The consultant. A company's flagship patent names two employees. During diligence, a consultant's engagement letter surfaces showing they participated in the design sessions where the key claim element was conceived. Their agreement transfers "all work product" but contains no present assignment of inventions. Analysis under Pannu v. Iolab suggests they contributed significantly to one independent claim. The company negotiates a confirmatory present assignment before the transaction, at a price. Had it waited until assertion, the consultant would have known what the patent was worth.

The departed engineer. A defendant asserts that a former employee is an unnamed co-inventor and produces a licence from them. If the assertion is correct, Ethicon v. United States Surgical means the licence is a complete defence. The plaintiff's response depends entirely on evidence: notebooks, disclosure forms, and design records showing who conceived the claimed subject matter. Where the records exist, the assertion fails; where they do not, the case is over.

The university spin-out. A startup's core patent was invented by a professor. The university's policy says inventions "shall be the property of" the institution, and the professor separately executed a present assignment to the startup. Under Omni MedSci v. Apple, the policy language may not have effected an automatic assignment, and under FilmTec v. Allied-Signal the present assignment to the startup may have taken title. The answer turns on the exact policy wording and the sequence — which is why this question is answered by reading documents rather than by asking who everyone assumed owned it.

Running the Determination

A repeatable procedure that takes an hour per patent and prevents most disputes.

Step one — print the claims. All of them, independent and dependent, as filed or as allowed depending on the stage.

Step two — decompose each claim into elements. The limitations that distinguish it from what came before.

Step three — for each element, ask who conceived it. Not who implemented it, not who supervised it, and not who paid for it. Who formed the definite and permanent idea, in the Burroughs Wellcome v. Barr Laboratories sense.

Step four — apply the Pannu filters. Was the contribution significant in relation to the full invention? Was it more than explaining well-known concepts or the state of the art? Was there collaboration?

Step five — build the inventor set. The union of inventors across all claims. A person who conceived the subject matter of one dependent claim is an inventor of the patent.

Step six — check the corroboration. For each named inventor, identify the records supporting their contribution. Where there are none, the naming is vulnerable.

Step seven — check the assignments. For each named inventor, is there a signed present assignment covering this invention, and is it recorded?

Step eight — check for unnamed contributors. Everyone on the project who is not named, with a note on why not. This is the step that finds the problem, and it is the step most often skipped.

Step nine — record the reasoning. A one-page memorandum per patent, dated. It is the answer to a later challenge, and it demonstrates that the determination was made rather than assumed.

Step ten — repeat at allowance. Claims change. Inventorship follows the claims.

Common Mistakes

Naming the project team. Inventorship is not authorship and it is not credit. Naming people who did not conceive claimed subject matter is as much an error as omitting people who did.

Determining inventorship once, at filing, and never revisiting it when the claims change during prosecution.

Assuming employment transfers ownership. It does not. 35 U.S.C. § 261 requires a writing, and the writing must say "hereby assigns."

"Agrees to assign" language, which after FilmTec v. Allied-Signal and Omni MedSci v. Apple may transfer nothing until a further instrument.

Relying on a policy or handbook rather than an executed agreement.

Onboarding contractors without an assignment, on the assumption that a work-product clause covers patents.

Correcting inventorship without collecting the assignment, which converts a formal defect into a co-ownership problem under 35 U.S.C. § 262.

Discovering the gap during litigation, when the omitted inventor has leverage and the defendant has an interest in their non-cooperation.

Filing suit before the chain is complete, since standing is assessed at filing and a nunc pro tunc assignment generally does not cure it.

Failing to record assignments, exposing the portfolio to a subsequent bona fide purchaser under 35 U.S.C. § 261.

Destroying invention records on a general retention schedule, years before the assertion that will need them.

Ignoring state statutory limits on employee invention assignment agreements, and the notice requirements that accompany them.

Diligence Questions

For each patent, who are the named inventors and what is the evidence of their contribution?

Who else worked on the project and why are they not named? The absence of this analysis is itself a finding.

Is there a signed present assignment from every named inventor? With "hereby assigns" language, executed before or contemporaneously with the invention.

Is every assignment recorded under 37 C.F.R. § 3.11, and does the recorded chain reach the current owner without gaps?

Were any inventions made before the assignment was executed? Founder inventions and pre-employment conceptions are the recurring case.

Were contractors, consultants, or interns involved? And do their agreements contain present assignments?

Any university or government funding? Bayh-Dole obligations under 35 U.S.C. § 202 and institutional assignment policies both bear on title.

Any joint development? And does the agreement allocate foreground ownership, or does the 35 U.S.C. § 262 default apply?

Any prior corrections under 35 U.S.C. § 256, and were assignments obtained from newly named inventors?

Any exclusive licences? And do they transfer substantial rights such that standing has moved, on the Lone Star Silicon Innovations v. Nanya Technology analysis?

Do invention records still exist? A portfolio with no surviving conception evidence cannot defend an inventorship challenge, whatever the truth of the matter.

Managing Co-Ownership When It Exists

Sometimes co-ownership is the deliberate outcome, or the unavoidable one, and it can be managed.

The default is the problem. 35 U.S.C. § 262 permits each co-owner to practise and license without consent and without accounting. For a commercial patent, that default is close to useless to both owners.

Contract around it. The statute applies "in the absence of any agreement to the contrary," so a co-ownership agreement can restore what the default removes.

Terms worth including. A consent requirement for licensing, or a defined field allocation. An accounting obligation for revenue. Joinder covenants requiring each owner to join enforcement actions brought by the other, at that owner's cost. Cost sharing for prosecution and maintenance. A right of first refusal on transfer of an interest. And a mechanism for what happens when the owners disagree about enforcement.

Joinder is the critical term. Without it, one co-owner can prevent any enforcement, and the patent becomes purely defensive.

Field allocation is frequently the practical answer where the owners operate in different markets, and it converts a shared asset into two workable ones.

Maintenance responsibility. A patent lapses if fees are unpaid under 35 U.S.C. § 41, and co-owners each assuming the other is paying is a real failure mode.

Foreign counterparts. Co-ownership rules differ substantially outside the United States, and several jurisdictions require consent to license. An agreement should address each jurisdiction where the family is filed.

Transfer restrictions. Without them, a co-owner can sell its interest to a competitor or an assertion entity, and the other owner acquires a partner it did not choose.

Where co-ownership is avoidable, avoid it. Assign to one entity and license back. The administrative simplicity is worth more than the symbolism of shared title, and the enforcement position is incomparably better.

The One-Page Position

Inventorship and title position — [portfolio], [date]. Patents and applications: [N]. Inventorship determinations documented claim by claim: [N] of [N]; determinations refreshed at allowance: [N]. Unnamed contributors identified and analysed: [N] projects reviewed, [N] potential co-inventors assessed, [N] resolved by confirmatory assignment, [N] outstanding. Assignments: present-tense "hereby assigns" language in place for [N] of [N] named inventors; [N] gaps, of which [N] are contractors and [N] are pre-employment conceptions. Recordation: [N] of [N] recorded under 37 C.F.R. § 3.11; chain complete to current owner on [N]. Corrections under 35 U.S.C. § 256: [N] filed, [N] with assignments obtained. Co-owned patents: [N], of which [N] are governed by a co-ownership agreement addressing licensing consent, accounting, and joinder. Exclusive licences with potential standing effect: [N], assessed under Lone Star Silicon Innovations v. Nanya Technology. Invention records retained for [N] of [N] priority patents. Enforcement readiness: [N] patents assertable today without a title defect. Recommended actions: [obtain confirmatory assignments from X / correct inventorship on Y before assertion / record the chain on Z / negotiate a co-ownership agreement for the joint family].

A Closing Note

Two sentences carry most of this toolkit.

Inventorship is determined claim by claim, by conception, and a person who conceived the subject matter of a single dependent claim is an inventor of the whole patent.

Ownership follows inventorship unless a written instrument saying "hereby assigns" transferred it before the invention existed.

Everything else — the correction mechanisms, the standing analysis, the co-ownership arrangements, the litigation over notebooks — is remediation for one of those two sentences having been ignored at a point when honouring them would have cost an hour and a signature.

Questions Clients Ask

Our CTO supervised the project. Are they an inventor? Only if they conceived the subject matter of at least one claim. Supervision, direction, and funding do not make someone an inventor.

Our engineer built it. Are they an inventor? Only if they contributed to conception. Reducing another's conception to practice under direction does not qualify.

Everyone contributed something. Should we name them all? No. Over-naming is an error in the same way under-naming is, and it creates co-owners with the full 35 U.S.C. § 262 rights.

We employ them. Don't we own it? Not automatically. 35 U.S.C. § 261 requires a written assignment, and the language must be a present grant.

Our handbook says inventions belong to the company. Omni MedSci v. Apple held that "shall be the property of" language did not automatically assign. Get a signed present assignment.

The inventor left and will not sign. A power of attorney in the original agreement permits execution of confirmatory documents. Absent that, 35 U.S.C. § 118 permits filing by a party with sufficient proprietary interest in defined circumstances, and a contract action may be available.

We forgot to name someone. Is the patent invalid? Correctable under 35 U.S.C. § 256, and Pannu v. Iolab directs courts to consider correction before invalidating. Obtain the assignment when you correct.

Can our co-owner really license our competitor? Yes, under 35 U.S.C. § 262, without consent and without accounting — unless an agreement provides otherwise.

Can we sue without our co-owner? Generally no. Ethicon v. United States Surgical is the reason one unwilling co-owner ends an enforcement programme.

Our exclusive licensee wants to sue alone. Depends on whether substantial rights transferred, on the Lone Star Silicon Innovations v. Nanya Technology analysis. Read the licence.

We are acquiring a portfolio. What is the one question? Whether every named inventor signed a present assignment before the invention existed, and whether it was recorded. Everything else in title diligence is downstream of that.

Can an AI system be an inventor? No. 35 U.S.C. § 100 requires an individual, and only natural persons qualify. Where a tool assisted, the human contributions to conception are what must be identified and documented.

Model Language

Present assignment core clause.

"Employee hereby assigns, transfers, and conveys to Company Employee's entire right, title, and interest in and to all Inventions, together with all patent applications and patents claiming such Inventions, in all countries. This assignment is effective as of the creation of each Invention without any further act by Employee or Company."

Scope definition.

"'Invention' means any invention, discovery, improvement, or work of authorship conceived or reduced to practice by Employee, alone or with others, during the period of employment, that (a) relates to the Company's business or actual or demonstrably anticipated research or development, or (b) results from work performed for the Company, or (c) was developed using Company equipment, supplies, facilities, or confidential information."

Statutory notice, where applicable.

"This assignment does not apply to any invention that Employee developed entirely on Employee's own time without using Company equipment, supplies, facilities, or trade secret information, except for inventions that either (a) relate at the time of conception or reduction to practice to the Company's business or actual or demonstrably anticipated research or development, or (b) result from any work performed by Employee for the Company. Employee acknowledges receipt of this written notice."

Further assurances and power of attorney.

"Employee shall execute all documents and take all actions reasonably requested by Company to perfect, record, and enforce the rights assigned. If Company is unable, after reasonable effort, to secure Employee's signature, Employee hereby irrevocably appoints Company and its officers as Employee's attorney-in-fact to execute and file such documents with the same legal effect as if executed by Employee."

Disclosure obligation.

"Employee shall promptly disclose to Company in writing every Invention, including the date of conception, the persons who contributed to conception, and the records evidencing it, whether or not Employee believes it is patentable."

Prior inventions schedule.

"Employee has listed on Schedule A all inventions conceived before employment that Employee wishes to exclude. If no list is provided, Employee represents there are no such inventions."

Contractor variant. The same present-tense grant, scoped to inventions arising from the services, with an express statement that no work-made-for-hire doctrine applies to patents and that this instrument is the operative transfer.

Co-ownership agreement essentials.

"Neither party shall grant any licence under the Joint Patents without the other's prior written consent, except within its Exclusive Field. Each party shall account to the other for [percentage] of net revenue received under any such licence. Each party shall, on request and at the requesting party's cost, join as a party to any action brought by the other to enforce the Joint Patents. Neither party may assign its interest without first offering it to the other on the same terms."

What This Costs

The agreement. One template, adapted for the states where the company hires, executed at onboarding. Effectively free at the margin.

The invention record. An hour per invention, capturing conception, contributors, and corroboration.

The determination. An hour per patent at filing and thirty minutes at allowance.

Recordation. A nominal fee per assignment under 37 C.F.R. § 3.11.

Correction under 35 U.S.C. § 256. By petition, modest. By district court action, a litigation.

A confirmatory assignment from a departed inventor. A negotiation whose price rises with the patent's demonstrated value — which is why the time to obtain it is early.

A standing dismissal. The case, plus refiling, plus whatever the limitations period took in the interval.

A co-owner's licence to the defendant. The case, entirely, with no remedy.

The asymmetry is the point. Two hours per patent, spent at the right time, against the loss of an entire enforcement programme.

A Suggested Reading Path

For the determination:

For the ownership side:

For the enforcement consequences:

Primary Authorities

| Authority | Proposition | |---|---| | 35 U.S.C. § 100 | Inventor definitions | | 35 U.S.C. § 101 | Whoever invents may obtain a patent | | 35 U.S.C. § 115 | Inventor's oath or declaration | | 35 U.S.C. § 116 | Joint inventors | | 35 U.S.C. § 118 | Filing by other than the inventor | | 35 U.S.C. § 135 | Derivation proceedings | | 35 U.S.C. § 256 | Correction of inventorship | | 35 U.S.C. § 261 | Ownership; assignment; recordation | | 35 U.S.C. § 262 | Joint owners | | 35 U.S.C. § 281 | Civil action for infringement | | 37 C.F.R. § 1.48 | Correction of inventorship in an application | | 37 C.F.R. § 1.63 | Inventor's oath or declaration | | 37 C.F.R. § 3.11 | Recordation of assignments | | 37 C.F.R. § 3.73 | Establishing right of assignee | | Burroughs Wellcome v. Barr Laboratories | Conception standard | | Pannu v. Iolab | Joint inventorship factors | | Hess v. Advanced Cardiovascular Systems | State of the art contributions | | Trovan v. Sokymat | Claim-by-claim analysis applied | | Ethicon v. United States Surgical | Co-owner licence defeats suit | | FilmTec v. Allied-Signal | Present assignment of future rights | | Board of Trustees of Stanford University v. Roche | Bayh-Dole does not vest title | | Omni MedSci v. Apple | Policy language and automatic assignment | | Lone Star Silicon Innovations v. Nanya | Substantial rights and standing | | 35 U.S.C. § 200 | Bayh-Dole policy | | 35 U.S.C. § 202 | Election of title |

Forms and Templates

The Assignment Agreement Template is the single most important document in this area, and the operative sentence is the one nobody reads: it must say "hereby assigns" rather than "agrees to assign," because FilmTec v. Allied-Signal and Omni MedSci v. Apple turn on exactly that distinction, and a promise to assign leaves legal title with the inventor. It should be executed at hiring rather than at filing, should cover inventions made during employment and within scope, should include a further-assurances covenant and a power of attorney for confirmatory documents, and should be adapted to the states that limit the reach of such agreements. The Portfolio Inventory Template is where the assignment status of each patent should be recorded — inventors named, assignments executed, assignments recorded, gaps identified — because that column is the first thing a buyer's counsel asks for and the last thing most companies can produce. The License Agreement Template matters because an exclusive licensee's standing depends on whether substantial rights transferred, which is a question of what the licence actually grants rather than what it is called.

Related Toolkits and Checklists

The Patent Post-Issuance Correction Toolkit covers correction under 35 U.S.C. § 256 alongside the other post-grant mechanisms, and the Inventorship Determination Checklist runs the analysis claim by claim. For the joint development context, where background IP and foreground ownership are negotiated rather than defaulted, Structuring a Joint Development Agreement and the Joint Development Agreement Checklist cover the agreement architecture. The Patent Litigation Toolkit covers the standing consequences, which are where inventorship defects usually surface. And the IP Due Diligence Toolkit covers the chain-of-title review that finds them before a transaction rather than during one.