The purpose of filing a PCT (Patent Cooperation Treaty) application is to buy the applicant time within which to decide upon countries of interest for filing in at a later date. The PCT procedure allows the applicant to temporarily retain the right to apply for patents in more than 100 different contracting countries of the PCT, including regional designations, which encompass a vast majority of neighboring countries located in that particular region (for example, Europe).
The PCT application (the “Request”) must be filed within one year of the filing date of the applicant’s first U.S. application (which is the “priority date”). Frequently, the applicant’s first U.S. application is a provisional application, which expires after one year, which means that the PCT patent application usually needs to be filed at the same time as any then filed U.S. utility application. You can get more detailed info from https://www.advfn.com/newspaper/advfnnews/50958/let-inventhelp-assist-with-your-invention-idea.
Once the applicant files the PCT application, the applicant is given a period of 30 months (2 ½ years) from the priority date to file national stage patent applications in any PCT countries. That is usually 18 months after filing the PCT application, which is usually filed 12 months after the priority date.
Six months after the Request has been filed, the application will be published by the World Intellectual Property Organization. At about that time, you should receive your International patentability search report, which is an excellent predictor of your U.S. search results.
The PCT application typically expires on the 30-month deadline. The applicant should decide which countries to file in as the 30-month deadline approaches. When considering filing internationally, the applicant should first establish a budget for costs, and then consider the potential for marketability of the product in that particular country or countries. Once marketability has been established, the applicant then selects (designates) the countries of interest, and proceeds with filing the applications in the designated countries as stated in https://www.tmcnet.com/topics/articles/2019/05/23/442268-turn-idea-into-new-product-with-assistance-from.htm article.
International costs, including filing costs, prosecution costs, and annuities that must be paid in order to maintain the patents, will vary from country-to-country.