Priority Dates

1Priority date serves many purposes. First, it helps one to ascertain the date on which the rights in the patent came into force for the purpose of ascertaining infringement and prior art. (See Patents Act 1970, ss 13(1)(b), 18(1)(a), 18(2)(a), 18(3), 25(1)(b) to (e), 25(2)(b) to (e), 26(2), 29(2), 32, 57(5), 64(1)(a), 64(1)(e), 64(1)(f), 64(1)(l), 100(2), 135(1), 135(3) and 137.) Secondly, it helps the patentee to file multiple patent applications in different jurisdiction citing an earlier priority date under the PCT. The filing date of an application under s 7(1A) and its complete specification processed by the Patent Office as designated office or elected office shall be the international filing date accorded under the PCT. (Ibid, s 7(1B).)

2Every claim should have a priority date. (Ibid, s 11(1).) As a rule, the date of priority of a claim shall be the date of filing of the complete specification. (Ibid, s 11(6).) This rule is, however, subject to certain conditions stipulated in the Act. (See ibid, ss 11(2), 11(3), 11(3A), 11(4), 11(5) and 137.) Section 11 explains certain situations, which are listed below, where the determination of priority date does not follow the above rule. The priority date of the claim in a complete specification shall be the date of filing of the provisional specification, provided the claim is fairly based on the matter disclosed in the provisional specification. (Ibid, s 11(2).)