Intellectual Property

When a patent application has been filed without authorization

A joint development partner has filed a patent application in its own name alone for technology your company was developing. Or an engineer who has left the company has filed in their own name. When something of this kind comes to light, the first point to check is the stage the application has reached. The procedures available differ depending on whether the application is still pending or the patent has already been registered.

Nor does the conclusion that the rights belong to your company follow from the facts that your company bore the development costs, or that internal approval was not obtained. Who made the invention, to whom the right to obtain a patent belonged, and to whom it was transferred, are checked step by step.

Last updated: September 18, 2026

What to check first

The application number, filing date, priority date, whether the application has been published, the status of examination, and whether the patent has been registered

Whether there are divisional applications or foreign applications

The application documents as originally filed, and the claims, description and drawings as amended

The deadline for requesting examination, and the status of payment of registration fees and annual fees

Joint development agreements, confidentiality agreements, employee invention regulations, and documents relating to assignment

Whether the removal of technical materials or their use for purposes outside the agreed scope is also suspected

How we can helpChecking the status of the application or registration and the contractual relationship / Considering the inventor and ownership of the right / Preserving evidence and interviewing those involved / Steps concerning the applicant's name and succession while the application is pending / Claims for transfer of a registered patent and invalidation trials / Negotiations, litigation and continuity of the business

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Contents

1. Is the application pending, or has the patent been registered?
2. The development history, technical contribution, and preserving evidence
3. The inventor and ownership of the right to obtain a patent
4. Assessing usurped applications and breach of the joint application requirement
5. Steps while the application is pending: the applicant's name and succession
6. Claims for transfer of a registered patent and invalidation trials
7. Negotiations, litigation and continuity of the business
8. How we assist
Key legislation and official sources
Frequently asked questions

1. Is the application pending, or has the patent been registered?

A patent right comes into existence upon registration of its establishment. Because the procedures that can be considered differ between the pending stage and the stage after registration, this is the first point to check.

Where recovery of the rights is the objective, whether examination has been requested and by when, and the status and deadlines for payment of registration fees and annual fees, are also checked. These deadlines continue to run while ownership is in dispute. If no request for examination is filed within the applicable period, the application is, as a general rule, deemed to have been withdrawn. As to patent fees, if payment is not made in accordance with the prescribed procedure and within the prescribed period, this can lead to dismissal of the application or extinguishment of the patent right. Relief is available in some cases, subject to requirements and time limits, but recovery is not a matter of course. Alongside negotiations or litigation, it is necessary to consider who is able to take the steps needed to maintain the application and the right, and how that is to be secured.

A request for examination of an application may be filed by a person other than the applicant, and patent fees may in some cases be paid by a person other than the person liable to pay them. A request for examination may not be withdrawn, however. The choice of procedure, including approaches that do not depend on waiting for the other party to act, is made in light of the relative weight given to maintaining the right and to keeping the technology unpublished.

Where the application has not yet been published, the expected timing of publication and the procedures under way with their deadlines are checked together. For technology that has not been published, recovering the right as a patent and avoiding publication of the technology can be different objectives. In parallel with investigating ownership, it is necessary to decide which of these carries more weight, and to consider whether any agreement or preservative measure is available. Starting negotiations or litigation does not stop publication, so the progress of the procedures needs to be monitored on a continuing basis.

In checking the technical content, one option is to compare the application documents as originally filed with the claims, description and drawings as amended, rather than relying on the title of the invention or the abstract alone. Amendments may have brought the application closer to your company's technology.

As to the contractual position, one option is to review joint development agreements, confidentiality agreements, employee invention regulations and documents relating to assignment, and to set out separately whether there was consent to the filing and what was agreed as to ownership of the rights.

Where the removal of technical materials, their use for purposes outside the agreed scope, or disclosure to third parties is suspected, responses based on trade secret infringement under the Unfair Competition Prevention Act or on breach of confidentiality obligations are considered separately from ownership of the application. This is dealt with in our separate legal guides on suspected removal of information by former employees and on responding to misuse of trade secrets by competitors.

2. The development history, technical contribution, and preserving evidence

One option is to preserve research notebooks, drawings, experimental results, programs, emails and minutes in a state in which the author, the date of creation and the history of changes can be verified. Where the ownership of an invention is disputed, materials showing when, by whom, and what was conceived and reduced to practice play a central role.

In considering who the inventors are, one option is to identify the technical features of the invention concerned, and then to set out, following the course of the development, how each person contributed to conceiving or reducing to practice the means of solving the problem.

The point that calls for care here is the assessment of contribution. It is necessary to avoid treating a person as a joint inventor merely because they set the direction of the research, provided funding, or exercised general management or supervision. In identifying inventors, the question considered is what creative contribution each person made to the conception or reduction to practice of the means of solving the problem, in light of the technical features of the invention. A person's position in the organization, or a relationship of direction and supervision, does not in itself determine the outcome. In reviewing the matter internally, setting out for each claim the technical features, the persons who contributed, the timing of completion, the supporting materials and the history of succession makes it less likely that the identification of inventors will be confused with the history of the acquisition of rights.

It is also possible to compare the content, timing and participants of any disclosures of technology to the other party with the other party's own development records, in order to check how the information that resulted in the application was obtained. In interviewing those involved, it is important to keep explanations based on contemporaneous records separate from later recollection or supposition.

3. The inventor and ownership of the right to obtain a patent

Who the inventor is, and whether the company has acquired the right to obtain a patent, are different questions. They need to be considered separately.

The right to obtain a patent may be transferred.

As a starting point, not every invention made by an employee is an employee invention, which is an invention made by an employee that falls within the scope of the employer's business and that results from acts falling within the employee's present or past duties for the employer. Whether the invention falls within the scope of the company's business, and whether the acts that resulted in the invention fall within the employee's present or past duties at that company, are checked. Where the application was filed after the employee left, the analysis covers not only the timing of the filing but also when the invention was completed and in relation to which duties.

For employee inventions completed on or after April 1, 2016, where a contract, employment regulations or other stipulation provides in advance that the right to obtain a patent is to vest in the employer, that right belongs to the employer from the time it arises. Without such an advance stipulation, the company does not acquire the right merely because an employment relationship exists.

For inventions completed before that date, rather than this rule on vesting from the time the right arises, what is checked is whether there was a succession based on a contract or internal regulations, and which legislation applies to that succession. The analysis separates not only the filing date and the date of leaving employment, but also the time the invention was completed, the period of application and content of the internal regulations, and whether there was an individual assignment.

Even where the vesting or succession of rights to the company is established, the treatment of reasonable benefits and similar entitlements for the employee is checked separately, in line with the applicable legislation and the contract or internal regulations.

Where the right to obtain a patent is co-owned, a co-owner may not assign its share without the consent of the other co-owners.

One option is to trace the history of the acquisition of rights by separating the vesting or succession from each inventor to their employer from the succession between companies, working from the contractual documents in existence at each point in time.

4. Assessing usurped applications and breach of the joint application requirement

Where the right to obtain a patent is co-owned, a co-owner may not file a patent application except jointly with the other co-owners. An application filed in breach of this is a ground for a decision of refusal. It is likewise a ground for refusal where the applicant does not hold the right to obtain a patent for the invention. The former is breach of the joint application requirement; the latter is what is known as a usurped application, that is, an application filed by a person who is not entitled to obtain the patent.

What has to be distinguished here is the contractual obligation to file jointly and the joint application requirement under the Patent Act. Even where a joint development agreement provided that applications would be filed jointly and the other party nonetheless filed alone, that fact alone does not establish a breach of the joint application requirement under the Patent Act. What that requirement turns on is whether the right to obtain a patent is in fact co-owned. Breach of the contractual obligation is framed separately, as a claim based on the contract.

Similarly, it is necessary to avoid concluding that an application is a usurped application merely because it has points in common with your company's technology. What is checked is the identity of the invention concerned, the history of its creation and of any succession, and the basis of title asserted by the other party.

5. Steps while the application is pending: the applicant's name and succession

At the pending stage, the issues are the effect of a succession and its effect against third parties.

A succession to the right to obtain a patent before a patent application is filed cannot be asserted against third parties unless the successor files the application. A succession to the right to obtain a patent after the application has been filed does not take effect unless it is notified to the Commissioner of the Japan Patent Office, except in the case of inheritance or other general succession. The notification follows the form prescribed by the regulation under the Patent Act. In the case of inheritance or other general succession, notification is not a condition for the succession to take effect, but the successor must notify the Commissioner of the Japan Patent Office without delay.

These provisions, however, lay down requirements for the effect of a succession and for asserting it against third parties; they do not in themselves give rise to a right to have the position corrected. Where the aim is to correct the name in which a suspected usurped application stands, the availability of a claim to confirm ownership of the right, or a claim requiring cooperation in the necessary procedures, is considered in light of the history of the acquisition of the rights, the case law and the procedures of the Japan Patent Office. The claim for transfer of a patent right discussed below applies to patent rights after registration, and is not a direct basis for a change of applicant while the application is pending.

Companies sometimes consider using the third-party observation procedure, by which any person may submit information to the Japan Patent Office about a pending application. The grounds listed as subject matter for such submissions in the regulation under the Patent Act are the addition of new matter by amendment, novelty and inventive step and related grounds, requirements as to the description, and statements going beyond the scope of a foreign language document. Observations on the ground of breach of the joint application requirement or of usurpation cannot be made under this procedure. This does not preclude submitting information on a separate ground, such as lack of novelty, in relation to the same application. Even so, the existence of earlier development records at your company and the existence of publicly known prior art that defeats novelty are two different things. In addition, documents submitted with observations are in principle open to inspection, so where materials containing confidential information would be submitted, the necessity for doing so and the extent of the disclosure need to be checked in advance. Steps taken to protect confidentiality can themselves lead to further publication.

Nor does the filing of litigation over ownership automatically suspend examination or publication of the application. The Patent Act goes no further than to provide that examination proceedings may be suspended until the litigation is concluded where this is considered necessary.

6. Claims for transfer of a registered patent and invalidation trials

For the period after registration of the establishment of a patent right, the Patent Act provides a procedure for claiming transfer of the patent. This procedure applies to patent applications filed on or after April 1, 2012. The dividing line is the date of the application, not the date of registration, so the claim may not be available for patents based on older applications. Where the patent was granted in breach of the joint application requirement, or on a usurped application, a person holding the right to obtain a patent for the invention concerned may demand that the patent owner transfer the patent right, in accordance with the ordinance of the competent ministry.

Where a patent right is transferred and registered on the basis of such a claim, the patent right is deemed to have belonged to the person in whose name it is registered from the outset. The same applies to the right to claim compensation for working the invention after publication of the application.

Where a share in a co-owned patent right is transferred on the basis of such a claim, the provision requiring the consent of the other co-owners for the assignment of a share does not apply.

As to invalidation, a trial for patent invalidation may be requested only by an interested person, but where the request is based on breach of the joint application requirement or on usurpation, it may be requested only by a person holding the right to obtain a patent. It is not open to anyone to request it.

Where a trial decision invalidating a patent on the ground of breach of the joint application requirement or of usurpation becomes final, the patent right is deemed never to have existed. The procedure to choose differs according to whether the objective is to recover the right for your company or to extinguish the other party's patent. The approach is decided after clarifying whether, from a business perspective, the aim is to hold the technology exclusively or simply to prevent another company from holding it exclusively.

Once a transfer is registered on the basis of this statutory claim, the treatment of the grounds of invalidity relating to breach of the joint application requirement and usurpation also changes. Because the effects differ from those of a transfer by simple assignment, the legal basis of the transfer and the content of the registration are checked where the matter is resolved by settlement. Obtaining a transfer does not resolve other grounds of invalidity, such as lack of novelty or inventive step.

Another procedure for review after registration is an opposition to a granted patent, but breach of the joint application requirement and usurpation are not among the grounds on which an opposition may be filed. Where other grounds, such as lack of novelty or inventive step, are at issue, the available procedures are considered separately.

Where agreement on a transfer cannot be reached, civil litigation against the current patent owner is considered. A trial for patent invalidation, by contrast, is a procedure before the Japan Patent Office. Where the applicant originally named and the current owner are not the same, the history of transfers and the question of whom the procedures should be directed against are checked as well.

A point calling for care here is that a claim for transfer may recover no more than a share. In cases involving breach of the joint application requirement, even where your company recovers its share and the patent becomes co-owned, each co-owner may work the patented invention without the consent of the other co-owners, except where the contract provides otherwise. Recovering a share does not in itself stop the other party working the invention. This arises in the same way whether co-ownership results from a settlement or from recovery through the courts.

7. Negotiations, litigation and continuity of the business

In negotiations, one option is to clarify whether the objective is to acquire and maintain the right or to have the other party's patent invalidated, and to consider claims for performance and damages under the contract separately from claims under the Patent Act.

A provisional disposition is a Japanese court procedure for interim relief pending a decision on the merits. Where there is a risk that recovery of the right will become difficult through assignment to a third party, abandonment or similar steps, one option is to identify the right to be preserved and the measure sought, and then to consider whether a provisional disposition is available.

Where, conversely, the other party is asserting its rights against your company, then in addition to asserting that the rights belong to your company, the analysis covers whether the products or processes concerned fall within the technical scope of the patented invention, whether grounds of invalidity exist, and whether there is a basis for a license. The technical scope of a patented invention must be determined on the basis of the statements in the claims attached to the application.

As to licenses, there is a provision granting a non-exclusive license to a person who, without knowing the content of the invention claimed in the application, made the invention themselves, or learned it from such a person, and who at the time of the filing is commercially working the invention in Japan or preparing to do so. The scope of that non-exclusive license is limited to the invention and the purpose of the business that was being worked or prepared for. On the detailed requirements and general defenses available to an alleged infringer, see the guide on responding to a warning of intellectual property infringement.

It should also be noted that the range of persons who may request a trial for patent invalidation and the range of persons who may argue in infringement litigation that a patent should be invalidated are not the same. Where the other party is asserting its rights, what can be argued as a defense in the proceedings is considered separately from standing to request a trial.

As to damages for the unauthorized filing, for disclosure and for working the invention, rather than drawing conclusions from whether a claim for transfer succeeds, the unlawfulness or breach of contract involved in each act, the grounds of attribution, the loss and causation are considered individually.

8. How we assist

We review the status of the application or registration and the contractual position, and set out the approach to recovery of the right, invalidation, and claims under the contract

We consider the identification of inventors and the ownership of rights on the basis of development records and technical materials, and assist with preserving evidence and interviewing those involved

We set out the arguments and the terms to be agreed on ownership, cooperation in the application procedure and damages, in negotiations with joint development partners or former employees

We handle procedures concerning ownership and succession while an application is pending, and claims for transfer and trials for invalidation after registration, taking into account how these procedures relate to one another

We set out the claims and evidence where continuity of the business is under consideration and where trade secret infringement or breach of confidentiality obligations also arises

Key legislation and official sources

English translations of legislation are provided for reference. The Japanese texts are authoritative.

Where it appears	Legislation	Source type
Registration of establishment, requests for examination, patent fees and relief	Patent Act（特許法）	Japanese legislation / English translation
Employee inventions and the vesting of the right to obtain a patent	Patent Act（特許法）	Japanese legislation / English translation
Joint application requirement, usurped applications, and grounds of refusal	Patent Act（特許法）	Japanese legislation / English translation
Succession to the right to obtain a patent and notification to the Commissioner	Patent Act（特許法）	Japanese legislation / English translation
Claims for transfer of a patent right, invalidation trials and oppositions	Patent Act（特許法）	Japanese legislation / English translation
Non-exclusive license based on prior use; technical scope of a patented invention	Patent Act（特許法）	Japanese legislation / English translation
Compensation for working an invention after publication of the application	Patent Act（特許法）	Japanese legislation / English translation
Trade secret infringement where technical materials have been removed or disclosed	Unfair Competition Prevention Act（不正競争防止法）	Japanese legislation / English translation
Provisional dispositions where recovery of the right may become difficult	Civil Provisional Remedies Act（民事保全法）	Japanese legislation / English translation

Legal information reviewed: 2026-09-18

Frequently asked questions

Another company has obtained a patent for an invention made by our employee. Does this mean we can no longer work the invention?

Where an employee obtains a patent for an employee invention, or where a person who has succeeded to the right to obtain a patent for an employee invention obtains a patent for it, the employer has a non-exclusive license under that patent right. The first point to check is whether the invention is an employee invention. The next is to distinguish whether the other company obtained the patent after succeeding to the right to obtain a patent from the employee, or obtained it without holding the right. Where usurpation is suspected, whether the invention can be worked should not be assessed on the basis of this provision on non-exclusive licenses alone; ownership of the right and other available defenses are considered as well.

If we obtain a transfer of the patent right, what happens to the other party and to third parties who have been working the invention?

A person who, at the time the patent right is transferred and registered on the basis of such a claim, held the patent right, an exclusive license or a non-exclusive license, and who before that registration was commercially working the invention in Japan, or preparing to do so, without knowing that the patent was granted in breach of the joint application requirement or on a usurped application, has a non-exclusive license under that patent right, within the scope of the invention and the purpose of the business being worked or prepared for. Obtaining a transfer does not necessarily allow their working of the invention to be stopped immediately.

In that case, do we receive nothing?

The patent owner who receives the transfer is entitled to reasonable consideration from a person holding a non-exclusive license under that provision.

If we settle on terms under which the patent is co-owned, are we free to work the invention?

Where a patent right is co-owned, each co-owner may work the patented invention without the consent of the other co-owners, except where the contract provides otherwise. Granting a license to a third party does require the consent of the other co-owners, however, as does the assignment of a share. When settling, how these points are to be dealt with in the contract is considered.

The application has been published. Can we claim compensation?

Loss caused by the publication itself and compensation for working the invention after publication are separate questions. The Patent Act provides that, where a warning is given after publication of the application accompanied by a document stating the content of the invention, compensation equivalent to the amount that would ordinarily be received for working the invention may be claimed from a person who commercially works the invention after that warning and before registration of the establishment of the patent right. The same applies, even without a warning, to a person who commercially works the invention before registration knowing that it is an invention claimed in a published patent application. This right may be exercised only after registration of the establishment of the patent right.

Where your company is not the applicant, the first step is to work through the ownership of the right. Even where registration of a transfer settles who holds the right to claim compensation, whether the requirements for the claim are met, including the warning or the other party's knowledge and the working of the invention concerned, has to be checked separately. Where a transfer is registered on the basis of a claim for transfer, this right to claim compensation is likewise deemed to have belonged to the person in whose name it is registered from the outset. Loss of confidential information through unauthorized publication of the technology is considered separately, as a matter of breach of confidentiality obligations or trade secret infringement.

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