Divisional patent applications, as the name suggests are those patent applications that have been derived from another patent application. Section 16 of Indian Patents Act, 1970 deals with the provisions related to divisional applications.

Section 16(1) of the Patents Act states that "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."

While interpreting this sub-section, the Patent Office has usually held that while a first divisional application out of the parent application may be allowable, subject to the other requirements of Section 16 being fulfilled, a second divisional application or a cascading divisional application out of the first divisional application may not be allowable. The Patent office has usually considered the "first mentioned application" mentioned in Section 16(1) as referring to the grandparent application in case of a cascading divisional application and not the immediate parent application out of which the second divisional application was divided.

However, ambiguity as regards the interpretation of the provisions of section 16(1) has recently been resolved by the IPAB with its decision in the matter of National Institute of Immunology v The Assistant Controller of Patents and Designs (OA/21/2011/PT/DEL) dated March 25, 2015 wherein the IPAB has set aside the impugned order of the Controller in view of non-application of mind and remanded the case back to the Controller with directions to provide fresh opportunity for hearing and decide the case on merits.

Brief facts of the case

  • The original (parent) application no. 8/DEL/1997 was filed on 02/01/1997 and the patent was granted on 14/06/2002 under Patent No. IN 186770.
  • The first divisional application No. 346/DEL/2001 was filed by the appellant on 23/03/2001 and the same was granted on 31/03/2008 under patent no. IN 217322.
  • The second divisional application no. 264/DEL/2005 was filed by the appellant on 08/02/2005 on the basis of the objection from Patent Office in First Examination Report dated 17/08/2004 issued in the first divisional application no. 346/DEL/2001 wherein it is specifically stated under SI.3. "Claim 7 to 17" defines multiplicity of distinct inventions.

However, the second divisional application no. 264/DEL/2005 of appellant had been refused by the Controller on the basis of following two grounds:

  1. The subject application is invalid as it is derived from a divisional application no. 346/DEL/2001 which itself is a divisional application derived from parent application no. 8/DEL/1997; and
  2. The subject application is time barred as per Section 16(1) of the Patents Act, 1970 as it has been filed after grant of Patent under Parent application no. 8/DEL/1997.

The Board's Decision

The IPAB held that subject application 246/DEL/2005 was filed prior to the grant of first divisional application and the sequence of events and the relevant dates make it crystal clear that the second divisional application no. 264/DEL/2005 was also filed well within the time of limitation contemplated under Section 16(1) of the Patents Act, 1970.

Further, the IPAB also stated that affected parties like appellant should not be left in the lurch mainly on the basis of the objection raised by the Patent Office which necessitated the appellant to resort to filing divisional application without any remedial measures available in accordance with law.


In view of this order, it is quite evident that in case of divisional application out of another divisional application or cascading divisional application, the first divisional application is to be treated as "first mentioned application" as per Section 16(1) of the Indian Patents Act and the date of grant of the main patent has no bearing on applicant. This is a welcome precedent which clears the air for the Applicants to file further divisional applications out of another divisional application, subject to fulfilment of other provisions of Section 16 of the Indian Patents Act.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.