If a patent applicant has first applied for a patent with a member of the World Trade Organization (WTO) or in a foreign country, which reciprocally allows ROC nationals to claim patent priority, and if an ROC patent application for the same invention is filed within 12 months (6 months for design patents) from the filing date of that first patent application, the applicant can claim international priority in respect of the ROC patent application so as to have the filing date of the first patent application (i.e. the priority date) as its base date for determination of patentability. While making international priority claims, the patent applicant shall submit the original certified copy of the first patent application issued by the foreign country or the WTO member with which that first patent application is filed, within 16 months (10 months for design patents) from the earliest priority date (please refer to Article 29 of the Patent Act).

Certified priority documents used to be paper-only, but the Intellectual Property Office (IPO) started the electronic priority document exchange ("PDX") with the Japan Patent Office ("JPO") on December 2, 2013 in accordance with the "Memorandum of Understanding on Cooperation in PDX Program" signed by the two countries on November 5, 2015, to adapt itself to the development of electronic communication technologies and to free patent offices from the time and cost wasting process of repeatedly making paper copies, simplifying patent application processes as well as saving postage of said paper copies. The PDX program expanded to the Korean Intellectual Property Office ("KIPO") on January 1, 2016, in accordance with the "Memorandum Concerning Industrial Property Information Exchange and Electronic PDX" signed by the two countries on June 15, 2015. When filing a patent application with the IPO and using an earliest invention or utility model patent application filed in Japan or South Korea as a basic application for priority claim, there is no more need for the applicant to submit a written certified priority document to the IPO. The electronic priority documents can be exchanged by using the access code issued by the JPO or the KIPO (related regulations provided in Paragraph 1, Article 26 of the Enforcement Rules of Patent Act, the Operational Directions Governing Electronic Exchange of Priority Document between the IPO and the JPO ("Taiwan–Japan Directions") and the Operational Directions Governing Electronic Exchange of Patent Priority Document between the IPO and the KIPO ("Taiwan–Korean Directions")).

However, should an exchange of electronic priority documents be subject to the term limit regulated in Paragraph 3, Article 29 of the Patent Act, i.e. submitted within 16 months from the earliest priority date? The Supreme Administrative Court took an affirmative view toward this issue in its 2017-Pan-Zi-No.182 administrative judgment on April 13, 2017.

The patent applicant involved in the case filed an invention patent application with the IPO on September 2, 2014, and claimed priority for a patent application filed in Japan on September 3, 2013, but attaching neither any certified priority document nor any access code needed for electronic PDX. The IPO issued a formal letter requesting the applicant to supplement the certified priority document or the access code by January 3, 2015, but the required access code was not submitted by the applicant until January 9, 2015. Since the submission of the required document exceeded the statutory period, the IPO deemed that the priority claim of the application was not to have been made and thus rejected the patent application. The applicant first filed an administrative appeal but was rejected by the Ministry of Economic Affairs, which upheld the original decision. The applicant then brought the case to the Intellectual Property Court followed by the Supreme Administrative Court against the original decision, but the administrative lawsuit and the appeal were again dismissed.

The Supreme Administrative Court opines that while the patent application of this case was first filed in Japan and the PDX program applies, the 16-month limit for submitting either a paper certified priority document or an access code still shall be abided by to claim the priority rights. Should the submission fall within the required period of time, the priority claim shall be deemed to have not been made, in accordance with Paragraph 3 of Article 29 of the Patent Act.

The applicant argued that, pursuant to Item 5.1 of the Taiwan–Korean Directions, a declaration that electronic PDX is adopted was deemed to have filed the certified priority document within the statutory period, but in this case, an access code was required to be submitted within the statutory period according to the Taiwan–Japan Directions. The applicant then expressed that such practices were against the principle of equality. However, the Supreme Administrative Court holds a view that the issue pointed out by the applicant involved various reciprocity conditions agreed by and between WTO members during negotiations for details of implementing PDX programs. It is acceptable for different countries to attach different degrees of importance to diverse factors and interests while considering their own interests. Therefore, it is not convincing to say any procedural difference in the implementation of PDX programs is a violation of the principle of equality. The court finally dismissed the applicant's request.

In conclusion, although patent applicants are able to make international priority claims from earlier patent applications filed in countries such as Japan and South Korea via simplified electronic PDX programs, attention shall still be paid to the provisions and time limits specified in the Patent Act, as well as detailed regulations of various operational directions, so as to prevent any impairment of one's vital rights.