Even after its grant, a patent may still be subjected to objection from third parties. This is referred to as post-grant opposition. It is covered under Section 25(2) of the Patents Act of 1970 and Rules 55 to 62 of the Patents Rules of 2003. Post-grant opposition can be filed at the relevant office at any time following the grant of the patent but prior to the expiration of 12 months from the date of publication of the patent grant in the Indian Patents Journal.
Any interested party may, in accordance with this provision, give notice of their opposition as per rule 55A to the Controller of Patents, in the manner specified under section 25(2) of the Patents (Amendment) Act, 2005, on the basis of any of the grounds listed therein. Although the grounds for both pre-grant and post-grant opposition are identical, the procedure for the two is substantially different. Moreover, in the case of pre-grant opposition, any person can challenge the application, whereas a post-grant opposition can only be filed by an interested person.
Any person engaged in, or fostering research in the same field as that to which the invention relates, is included in the definition of a “person interested” under Section 2(1)(t) of the Indian Patents Act. Additionally, any corporation with a manufacturing, trade, or financial stake in the goods associated with the patented product may also be considered an interested person.
Post-Grant opposition can be made on any of the grounds specified in the Patent Act by filing a notice of opposition under form 7, addressed to the Controller of Patents. Following the receipt of the notice, the Controller of Patents is required to inform the patentee regarding the opposition to their patent and constitute an opposition board that shall review the opposition submitted by the opponent and further provide recommendations to the controller.
A hearing between the parties i.e., the patentee and the opponent, is scheduled by the Controller, wherein, the statements and supporting evidence presented by both the parties are reviewed at length. On the basis of this discussion along with the recommendation of the Opposition Board, the Controller determines the validity of the opposition notice and further notify the parties of its outcome.
In contrast to pre-grant opposition, a post-grant opposition has to be filed with an obligatory fee. Despite that, the procedure for pre-grant opposition is quicker than that for post-grant opposition. However, it must be kept in mind that although the proceedings for the two are mostly distinct, they serve the same purpose, i.e., preventing the grant of insubstantial patents.