A request for substantive examination must be filed by 48 months from the earliest priority date (or the international filing date if the international application claimed no priority). The deadline can be extended until 48 months in cases of force majeure events such as natural calamity or enemy-inflicted destruction, or objective obstacles such as sickness. However, to qualify for such late submission, the applicant must submit evidence of such force majeure events or objective obstacles to the NOIP for review and approval. It is difficult to obtain such approval and therefore, the applicant should avoid late submission.
