Under Section 25(2) of the Patents Act, 1970, notice of opposition to a patent after its grant may be given by any person interested

Since the Patents (Amendment) Act, 2005, Section 25(2) of the Patents Act, 1970 allows any person interested to give notice of post-grant opposition to the Controller at any time after the grant but before the expiry of one year from the date of publication of the grant. Four months was the period for opposition under the Act as first enacted, when opposition was filed after advertisement of the acceptance of the complete specification; that scheme was replaced by pre-grant opposition under Section 25(1) and post-grant opposition under Section 25(2).