In India, to file a divisional application, the parent (or main) application should include more than one invention. Section 16(1) of the Patents Act, 1970 (‘Act’) forms the legislative basis for filing divisional applications. As per Section 16, divisional applications may be filed whenever the parent application includes a plurality of distinct inventions. It is worth noting that under Section 10(5), the claims of a complete specification shall relate to a single invention or a group of inventions linked so as to from a single inventive concept. Thus, the presence of two distinct inventions in one application is a clear requirement for filing a divisional application. Moreover, Section 16(3) of the Act stipulates that none of the complete specifications (i.e., the parent application and the divisional application) should include claims for any matter claimed in the other. Thus, a divisional application to pursue similar claims, i.e., claims based on the same inventive concept is not allowed in India. In view of this requirement, the law relating to divisional applications is different from that of US and EP.
The Intellectual Property Appellate Board (‘IPAB’), has interpreted the provisions relating to divisional applications and has shed light on the same. In the initial case law relating to divisional applications, it has been held that the existence of plurality of invention in the parent application is a sine qua non for a divisional application whether it is filed suo moto by the applicant or to remedy Controller’s objection. Particularly relevant in this context is the order of the IPAB in the matter of L.G. Electronics v. Controller of Patents (2011), that put to rest the issue of whether the filing of a divisional application by an applicant, if he so desires, can be interpreted to mean that an applicant can, on his own, file a divisional application even when claims in the specifications relate to only one invention.
Thus, while it was clarified that the interpretation of ‘if he so desires’ is subject to the condition that the parent application contains more than one distinct invention, certain other issues relating to divisional applications, such as: (i) whether claims of a divisional application can be based on the disclosure of the parent application or do they have to be based on the claims of the parent application; (ii) whether a divisional of divisional is allowable; and (iii) how to assess if the claims of a complete specification relate to distinct inventions, i.e., lacks unity of invention, remained unclear. However, recent orders from the IPAB, have now adjudicated on aspects pertaining to eligibility of divisional application and have thrown some light into some of these issues that are discussed herein.
Whether claims of a divisional application can be based on the disclosure of the parent application
The recent orders of the IPAB in the cases Procter & Gamble Company v. The Controller of Patents & Designs; Esco Corporation v. The Controller of Patents & Designs; and UCB Pharma S.A. v. The Controller of Patents & Designs, leave little to doubt as to whether claims of a divisional application can be based on the disclosure of the parent application or they necessarily have to be a part of the subject matter claimed in the parent application.
The IPAB has held that the patent application can only be divided, if it claims more than ‘one invention’. The IPAB reasoned that “A plain reading of sub -section (1) of section 16 reveals that the very ground to accept divisional application is “on the ground that the claims of the complete specification relate to more than one inventions. Sections 10(5) further qualifies “more than one invention” to only such invention or group thereof which cannot be linked to make a single inventive concept”. Negating the contention that some additional claim(s) can also be allowed, which never formed part of the originally filed claims, the Appellate Board clarified that claims of a divisional applications have to be based on claims of the parent and not its disclosure/specification. It is thus held that the claims of divisional application shall have their root in the claims of the parent application.
Also, relying on the L.G. Electronics case, the IPAB reiterated that the divisional application shall not be filed with the same set of claims as the first mentioned application.
It will be interesting to see how the patent office devices an objective test to assess if the claims of divisional application have their root in the claims of the parent application. The presently prevalent practice of assessment followed by the controllers at the patent office, that involves a clinical comparison of words of the claims of the divisional and the parent application, may often be ineffective to serve to true intent of the law.
Whether a divisional of divisional is allowable
In the context of Section 16 of the Act, another issue that stems up is, whether Section 16 allows filing of a divisional application of a divisional application. That is to say, after the filing of a divisional application arising from a parent application, can a further divisional application arising from the first filed divisional application be filed before the grant of said first filed divisional application but after the grant of the parent application?
Based on a plain reading of Section 16, it is gathered that a divisional of a divisional application is not prohibited. This is because Explanation to Section 16 clearly states that after the first divisional is filed, said application is to be treated as a substantive and independent application which means it can become an initial application for filing of a further divisional application, provided the condition of plurality of invention is satisfied in the first divisional application. However, based on numerous Controller’s orders, it is clear that while multiple divisional applications filed from a parent application are found allowable by the patent office, a divisional application arising from a previously filed divisional application is not.
This issue was resolved, to a certain extent, by the order of the IPAB in the case of National Institute of Immunology v. The Assistant Controller of Patents & Designs and Milliken & Company v. Union of India and others. However, in these cases the further divisional application was found allowable because the Controller, in the first examination report (FER) of the further divisional application, had raised objections relating to the lack of unity of invention. To this extent, these orders did not settle the question about validity of such divisional applications unambiguously.
The recent order of the IPAB in the case of Esco Corporation v. The Controller of Patents & Designs, has held that filing of a divisional application arising out of a divisional application is allowable, provided that the above-mentioned condition is true for the divisional of a divisional as well, i.e., the claims of the divisional of divisional find its roots in the claims of the divisional application. Needless to mention, the divisional of a divisional application is subject to other conditions, such as presence of multiplicity of inventions and pendency of the first divisional application. Thus, the present order puts to rest the long-standing ambiguity and clarifies that a divisional of a divisional application is not invalid solely for the reason that it is carved from a previously filed divisional application.
How to assess if the claims of a complete specification relate to distinct inventions / lacks unity of invention
It is now an established principle of law that to file a divisional application, there must exist plurality of inventions in the parent application. Provided there are plurality of inventions in the parent application, either the applicant may file a divisional application on his own accord, or may decide to file the divisional application based on an objection raised by the Controller for lack of unity of invention in the parent application.
More often than not, in situations where a divisional application has been filed, either suo moto by the applicant, or based on an objection raised by the Controller, a Controller is likely to object that the divisional application is not valid, either based on the fact that parent application did not include plurality of inventions, or the claims of the divisional application fall within the scope of the parent application, and the divisional application ought not to have been filed in the first place. Therefore, there has been a long felt need as to how to correctly determine if an application indeed includes plurality of inventions for which an applicant can correctly file a divisional application.
In the Esco Corporation case, the IPAB has looked at the provisions of unity of invention in the Patents Act, 1970 and the rules of Patent Cooperation Treaty (PCT) to identify the manner in which determination of unity of invention should be made.
The Appellate Board observed that the basic premise for filing any divisional application is based on the requirement of Section 7 of the Patents Act, which mandates that every patent application should be filed only for one invention. Further, based on the interpretation of Section 10(5) of the Patents Act, 1970, which requires the claim or claims of a complete specification to relate either to a single invention, or a group of inventions linked so as to form a single inventive concept, the IPAB observed that no two inventions can be allowed in a single patent application, unless it conforms to a single inventive concept. Hence, the Board observed that either way, it is a single inventive concept which is allowable in one application, as per the statutory provisions of the Patents Act, 1970.
The IPAB, also relied on Rule 13 of PCT, which specifies that the requirement of unity of invention for a group of inventions claimed in an international application is fulfilled when there is a technical relationship among those inventions involving one or more special technical features, wherein the technical features define a contribution which each of the claimed inventions makes over the prior art, to establish the principle of ‘One Application One Inventive Concept (OAOIC)”, which is allowable in a single application.
Although IPAB has not provided any clear guideline for determining the presence of a single inventive concept in claims of an application, their reliance on Rule 13 of PCT is indicative of the fact that if there is no technical relationship among the inventions claimed in an application, the claims of the application would lack ‘unity of invention’. However, the IPAB has also cautioned that by the presence of different embodiments in the specification, which are claimed as independent set of claims, it should not be asserted that the application lacks ‘unity of invention’.
Thus, it is clear from the observations of the IPAB that based on determination of presence or absence of single inventive concept amongst claims of an application, it should be determined if the application has unity of invention, and accordingly determination should be made if a divisional application should be filed of not.
While the absence of single inventive concept in claims of an application allows an applicant to file a divisional application, the IPAB has also observed that in cases where the application does not lack single inventive concept, but the Controller has raised an objection of lack of unity of invention, the applicant should not be left without a remedy and, any divisional filed in pursuance of Controller’s objection, should not be disallowed.
As the law continues to evolve, applicants remain desirous of consistent practices being adopted by the Controllers to assess validity of their divisional applications. Owing to different practices adopted by applicants and the patent office, in the interest of justice and for the sake of uniformity of practice, the IPAB has laid down guiding principles to address this issue in the Esco Corporation. We look forward to these guiding principles being put into practice by the patent office by amending the guidelines for examinations of divisional applications.
[The authors are Partner and Joint Partner respectively in Intellectual Property Rights practice team in Lakshmikumaran & Sridharan Attorneys, New Delhi]
 Section 16. Power of Controller to make orders respecting division of application
(1) - A person who has made an application for a patent under this Act may, at any time before the grant of the patent, if he so desires, or with a view to remedy the objection raised by the Controller on the ground that the claims of the complete specification relate to more than one invention, file a further application in respect of an invention disclosed in the provisional or complete specification already filed in respect of the first mentioned application.
(2). The further application under sub-section (1) shall be accompanied by a complete specification, but such complete specification shall not include any matter not in substance disclosed in the complete specification filed in pursuance of the first mentioned application.
(3). The Controller may require such amendment of the complete specification filed in pursuance of either the original or the further application as may be necessary to ensure that neither of the said complete specifications includes a claim for any matter claimed in the other.
Explanation—For the purposes of this Act, the further application and the complete specification accompanying it shall be deemed to have been filed on the date on which the first mentioned application had been filed, and the further application shall be proceeded with as a substantive application and be examined when the request for examination is filed within the prescribed period.
 IPAB Order No. 83 of 2015 dated 25th Mar, 2015
 IPAB Order No. 17 of 2016 dated 2nd Mar, 2016
 Section 7 Form of application:
(1) Every application for a patent shall be for one invention only and shall be made in the prescribed form and filed in the patent office.