Lakshmikumaran & Sridharan 律师事务所An ISO 9001 / 27001 certified law firm

Post-dating of patent applications and its implications

By Someshwar Banerjee & Aruna Verma      


Post-dating means to change the priority date of a patent application to a later date. The Indian Patents Act facilitates a patent application, whether provisional or non-provisional, to be post-dated under Section 17 of the Patents Act, 1970, to a maximum of six months, from the date of making of such application, provided that the request for post-dating has been filed by the applicant before the grant of the patent. Similar provisions of post-dating a patent application also exist in New Zealand and United Kingdom. However, the United States of America does not have any provision for post-dating of patent applications.      

A double edged sword      

Justice N. Rajagopala Ayyangar in his “Report on the revision of the patents law” suggested addition of the provision for post-dating of a patent application, in line with the provisions provided in the then UK Patent Act. In certain cases, post-dating of a patent application may provide the applicants with an extension of time to complete certain post-filing formalities of the patent application. However the applicant should ensure that the invention covered by the patent application has not been publically disclosed either by the applicant himself or by any third party before post-dating the application. It is preferable if a thorough search of patent and non-patent literature is conducted to ensure that there is no disclosure of similar subject matter as that of the invention, by any third party, in the intervening period.      

Analysis of the Indian statute        

In situations where an applicant has filed a provisional specification followed by a complete after provisional (CAP) specification, the applicant, under Section 9(4), may request the Controller, any time before the grant of the patent, to cancel the provisional specification and post-date the provisional specification to the date of filing of the CAP. Under Section 17(1), the applicant has the option of filing a request to the Controller to post-date any application by a maximum period of six months from the original filing date. Such post-dating is subject to the provisions of Section 9.      

Does post-dating shift deadlines imposed by Section 9(1)?      

A common dilemma faced by applicants while post-dating a provisional specification is whether the deadline for filing the CAP application will be calculated from the original filing date or the post-dated date. It should be noted that Section 9(1) states that a CAP specification should be filed within 12 months of the filing date of the provisional application. Shifting of the CAP filing deadline by post-dating the provisional application is an issue not yet addressed by the IPAB or the courts.        

Referring to the history of Section 9(1), the amendments in 2005 deleted the portion of the then Section 9(1) which provided that complete specification may be filed at any time after twelve months but within 15 months from the filing of provisional specification if a request to that effect was made to the Controller and prescribed fee was paid.        

The deletion may be interpreted to indicate that the legislative intent was to impose a strict deadline of 12 months for filing of the CAP application from the filing date of the provisional specification. The courts may interpret that since Section 17 is subject to the provisions of Section 9, a post-dating under Section 17 will not extend the deadline imposed by Section 9(1). It is preferable if applicants file the CAP application within 12 months of the original filing date of the provisional application to avoid probable pitfalls.        

Can a provisional application be post-dated under Section 17 if a complete application has been filed already?        

Another interesting issue which arises is whether the applicant can post-date the provisional application under Section 17, if a CAP application has already been filed. In 1999, the Delhi High Court in Standipack Pvt. Ltd. v. Oswal Trading Co. Ltd. cited the then Section 9 and Section 17 and stated “The aforesaid provisions make it crystal clear that post-dating of the patent can be done only to the date of filing of the complete specification”. The amendments to Section 9 and Section 17 thereafter extended the deadline for filing a request of post-dating from any time before the acceptance of the complete specification to any time before the grant of the patent. This amendment may not change the interpretation made by the Delhi High Court regarding the interplay of the two sections. The implication of the decision of the Delhi High Court can be understood only after a detailed analysis of the facts and will be covered in a subsequent issue.        

Implications on PCT/Convention filings          

In situations where an applicant has missed the 12 month deadline for filing a convention application or PCT application taking priority from an Indian application, a popular approach is to post-date the priority Indian application. However, the same may not yield the intended result. For the sake of brevity, the implication of post-dating convention filings is considered in the context of practice by the United States Patent and Trademark Office (USPTO), the European Patent Office (EPO) and the World Intellectual Property Organization (WIPO).        


With reference to the practices adopted by the USPTO, § 201.13 of the Manual of Patent Examining Procedure (MPEP) states that “if the original filing date is more than one year prior to the U.S. filing no right of priority can be based upon the application”. One of the most cited treatise “Chisum on Patents” states: “In re Clamp (1966), the applicant filed a provisional specification on February 8, 1963, but thereafter post-dated it to March 6, 1963. The applicant filed in the United States on March 5, 1964. The Commissioner of Patents held that the United States application was not timely for purposes of Section 119. The original actual filing date is determinative. The Paris Convention "never contemplated the arbitrary creation of an artificial date’." Article 4(C) (4) of the Convention and the third paragraph of Section 119, on abandoned applications suggest that "the effect of starting the year running by the proper filing of a proper application cannot otherwise be eradicated”.        

Thus, the deadline to file the US convention application remains 12 months from the date of the original filing and not from the new filing date that may be assigned to the post-dated patent application.      


As per Article 87(4) of the European Patent Convention (EPC), the post-dated patent application may be considered as a priority application, provided that, at the date of filing the subsequent application, the previous application has been withdrawn, abandoned or refused, without being open to public inspection and without leaving any rights outstanding. The previous application may not thereafter serve as a basis for claiming a right of priority.        

The case law of the Boards of Appeal further elaborates “Swiss patent law allows a patent application to be postdated if it is subsequently amended. In T 132/90 the patent proprietor had claimed 11.3.1983, the original filing date of the earlier Swiss application, as the priority date for his European application dated 9.3.1984. In 1985 the Swiss Patent Office ordered that the filing date of the Swiss patent application be set at 1.7.1983 following subsequent completion of the technical documentation. The board of appeal concluded that the original application should serve as the basis for claiming a priority right and that the priority date was the filing date of the original application. The post-dating order did not take effect ab-initio, and the subsequent fate of the original application was immaterial as far as the priority date was concerned.”        

Since, at the time of filing the post dated application, the original application is not withdrawn or abandoned or refused, the original application will be considered to serve as priority application. Therefore, the deadline for filing the EP convention application will remain 12 months from the original filing and not from the new filing date that may be assigned to the post-dated patent application.        


On the other hand, the PCT provisions provide greater flexibility. As per Rule 26bis.1(c) of the PCT, “Where the correction or addition of a priority claim causes a change in the priority date, any time limit which is computed from the previously applicable priority date and which has not already expired shall be computed from the priority date as so changed.” Accordingly, if, at the time of post-dating the application, the deadline to file a PCT application had not expired, the deadline (time limit) to file the PCT application will be computed from the shifted priority date. In case the applicant has missed the deadline for filing a PCT application, under Rule 26bis.3, the applicant has to file a request with the Receiving Office, within two months from the twelve month deadline, for restoring the priority of the PCT application. The Receiving Office may restore priority on a case to case basis.      

Implications of post-dating priority application while filing convention application in India        

The Patents Act, 1970 does not explicitly address situations where a foreign priority patent application is post-dated and is subsequently filed in India. As per Section 135 when a patent application (basic application) is filed in a convention country, the applicant may, within twelve months from the date of making the basic application, file a patent application claiming priority from the basic application, in India. A strict interpretation of this section indicates that India may not recognize priority claim of a convention application taking priority from a post-dated foreign patent application whose original filing date is more than twelve months prior than the Indian application. Of course, the other interpretation is that the post-dated application is the basic application, once post-dating is permitted. There are no judicial pronouncements on this till date.        


Thus, applicants must exercise the option of post-dating a patent application after carefully weighing the possible implications. Post-dating is a grey area in Indian patent law and it will be interesting to see how the Indian Courts and the IPAB would interpret the provisions.

[The authors are Senior Associates in the IPR Division, Lakshmikumaran & Sridharan, New Delhi]
搜索 团队成员
Search People
Enter at least a name or a keyword to search