Taiwan–US priority document exchange: how the access code works in both directions

If you file in Taiwan on the basis of a US patent application, or in the US on the basis of a Taiwan application, the priority document no longer has to be sent on paper. Since September 4, 2026, the Taiwan Intellectual Property Office (TIPO) and the United States Patent and Trademark Office (USPTO) exchange priority documents electronically, and an access code can take the place of the certified copy. What has not changed is the deadline: the statutory period for the priority document is the same as before.

1. The short answer

• US application first, then Taiwan. Obtain an access code from the USPTO and give it to TIPO, in the Taiwan application form or later on the supplementary-documents form, within 16 months after the earliest priority date (10 months for design applications).
• Taiwan application first, then the US. Ask TIPO for an access code and use it at the USPTO under the USPTO’s own procedures.
• If the exchange fails. A network or system failure is treated as a timely submission once the two offices obtain the document by coordination. A wrong access code or wrong application data leads to a TIPO notice giving two months to correct the data or file a paper copy.
• Older applications. Applications filed before September 4, 2026 may also use the exchange.

For US applicants filing in Taiwan, we suggest using the access code as the default route, with the paper copy as a fallback; missing this deadline means losing the priority claim itself.

2. What was issued, and when it took effect

On September 4, 2026, the Ministry of Economic Affairs (MOEA) issued the Operational Directions for the Electronic Priority Document Exchange Program between the Taiwan Intellectual Property Office and the United States Patent and Trademark Office (in Chinese; the English name is TIPO’s). TIPO’s notice states that they took effect the same day. They implement Article 26(3) of the Enforcement Rules of the Patent Act, under which a priority document that TIPO and the office of first filing have exchanged electronically is deemed to have been submitted by the applicant.

The same day, TIPO amended seven forms, among them the application forms and the supplementary-documents form, adding fields for declaring electronic exchange where the priority application is a US application.

About the start date. The Chinese directions notice, TIPO’s Chinese press release, its Chinese instructions page and its Q&A all give September 4, 2026. TIPO’s English pages differ: one English news item, dated September 1, 2026, is titled “Officially Launched on September 1, 2026”, while an English press release of the same date says the program “will officially launch on September 4, 2026”. We follow the Chinese directions: September 4, 2026. As of October 19, 2026, TIPO’s patent regulation notices and bulletin board list no amendment to the directions.

In the directions, the first office is where the priority application was filed, the second office is where the later application claiming it is filed, and the access code is a case code issued by the first office through which the electronic file of the priority application can be retrieved and its application number, filing date and patent type confirmed. Taiwan already exchanges priority documents electronically with Japan and South Korea.

3. US application first, then Taiwan

Here TIPO is the second office (point 5 of the directions).

Get the access code from the USPTO. TIPO’s instructions page refers applicants to the USPTO for this. The starting point is the USPTO’s general PDX program page; when we checked it on October 19, 2026, it did not yet mention the Taiwan arrangement, so your US counsel should confirm the current USPTO steps.

Give it to TIPO. If you have the code at filing, the Taiwan application form carries it (the e-filing form has matching fields): tick the box for submitting the priority document by electronic exchange, tick “United States”, and state the US application’s filing date, application number, patent type and access code. If not, file the same details on the supplementary-documents form within 16 months after the earliest priority date for invention and utility model applications, or within 10 months for design applications (Patent Act, Arts. 29(2), 120 and 142(3); point 5(3)). These are statutory periods. If neither the access code nor a paper certified copy is in by then, the priority claim is deemed not to have been made (Art. 29(3)).

Three points are often overlooked:

• The access code replaces the document, not the priority claim. The first filing’s date, country and application number must still be declared when the Taiwan application is filed (Art. 29(1)).
• TIPO’s Q&A states that the exchange covers all patent types, but only US national applications; a PCT application filed with the USPTO as receiving office is outside it.
• TIPO sends no separate notice when the exchange succeeds (Q&A, question 7). An error on the applicant’s side comes back as a TIPO notice (point 7).

Why this matters commercially follows from Article 28(4): patentability is examined as of the priority date. Take a US company that filed a US application on a leak-proof travel-mug lid and then saw a competitor show a similar lid at a trade show before the Taiwan filing. In our reading, if the priority claim falls away, that show predates the Taiwan filing date and can be cited against the application as prior art. With the priority claim intact, patentability is examined as of the US filing date, which comes before the show.

4. Taiwan application first, then the US

Here TIPO is the first office (point 4 of the directions).

Ask TIPO for the access code on the request form for priority documents, ticking “access code (Japan, United States)”, on paper or electronically. TIPO issues one code per Taiwan application, usable for both Japan and the US with no limit on the number of uses; a paper certified copy for other countries can be requested on the same form (Q&A, questions 13 and 14). TIPO’s codes have four characters, letters A–F and digits (question 11). TIPO issues the code after the filing date of the Taiwan application has been confirmed (question 12), so we suggest requesting it when the Taiwan application is filed rather than waiting until US counsel asks for it.

Use it at the USPTO. The directions leave the US side to the USPTO’s own procedures (point 4(5)), and TIPO’s instructions page refers applicants to the USPTO for the details; your US counsel handles that side (see the note on the USPTO page in section 3). When the USPTO sends its list of priority claims, TIPO checks the filing date, application number and access code and, if they match, transmits the document (point 4(6)). A PCT application filed with the USPTO claiming Taiwan priority is outside the exchange (question 3).

5. When the exchange fails

Not the applicant’s fault. Where network problems, a system failure or a similar cause not attributable to the applicant keeps TIPO from obtaining the correct document within the statutory period, and the two offices then obtain it by coordination, the applicant is deemed to have submitted it within the period (point 6).

The applicant’s fault. Where the access code or the priority application data are wrong, TIPO is to notify the applicant to correct the data or file a paper certified copy within two months. If neither is done in time, the priority document is deemed not to have been submitted (point 7), and under Article 29(3) the priority claim is deemed not to have been made.

The directions do not say whether those two months may run past the 16-month period. In our reading the text does not exclude it, but we would not plan around it; giving the access code early leaves room to fix an error inside the statutory period.

Nor do the directions cover a system failure the offices cannot resolve. In our reading, the applicant is then left with the general rule in Article 17(2) of the Patent Act: an applicant who misses a statutory period because of a natural disaster or a cause not attributable to it may apply in writing for reinstatement within 30 days after the cause ends, but not once the delay exceeds one year, and must perform the missed act at the same time (Art. 17(3)); the request states the cause of the delay and the date it ended, with supporting evidence (Enforcement Rules, Art. 12). In an August 26, 2025 notice about certified copies the USPTO had issued late, TIPO confirmed that this route is open where the period for the priority document is missed for a cause not attributable to the applicant. It gave as examples of evidence a written document from the USPTO, or an e-mail to the applicant from an official USPTO mailbox, stating the reason for the delay and the priority application number (or order number), and said it decides each request on the facts of the case. Whether reinstatement is granted therefore turns on the evidence of the cause, and we would not build a filing plan around it.

6. Applications filed before September 4, 2026

Point 8 of the directions lets applications filed before the start date use the exchange, in both directions (Q&A, question 16). The provision matters most for Taiwan applications that claim US priority, are still within the 16 months (10 for designs) and have no certified copy on file. A Taiwan invention application filed before September 4, 2026 whose only priority claim is to a US application filed in September 2025, for example, has until January 2027; filing the access code on the supplementary-documents form is now an option alongside ordering the paper copy.

7. What to send us

What to do in a particular case, especially close to a deadline, depends on the dates and what is already on file. When you write to us, please include:

• A new Taiwan filing claiming US priority: each US application number, its filing date and patent type, and the access code, or a note that you are still waiting for it.
• A pending Taiwan application: the Taiwan application number, the priority data as declared, and whether a certified copy has already been filed.
• A Taiwan application that will be the priority basis for a US filing: the Taiwan application number, the date your US counsel needs the access code, and whether any other country needs a paper copy.
• A TIPO notice about a failed exchange: the notice and the date you received it.

The other items to settle before a Taiwan filing are in our Taiwan patent filing checklist, and the statutory periods are collected in Taiwan patent and trademark deadlines at a glance. For how we handle Taiwan prosecution, see our patent services.