A trademark applicant that has been filed in a country mutually recognizing priority with the ROC, may claim priority within six months following the filing date of which the trademark application was first filed in the given country. The filing date of the trademark in the ROC shall be the date when the trademark was first filed in that foreign country (i.e. priority date). However, the claim of priority shall be made at the same time as the application is filed, and the application shall clearly indicate the filing date of the basic foreign application and the name of the foreign country accepting the basic application. In addition, the applicant shall submit, within three months from the date following the filing of the trademark application in the ROC, a certified copy of the basic application as accepted by the government of the particular foreign country in order not to forfeit the priority right.（§20, Trademark Act）
Since our accession to the WTO on January 1, 2002, all member states of the WTO are entitled to claim priority in the ROC.
（https://www.tipo.gov.tw/ct.asp?xItem=206785&CtNode=6759&mp=1）