The most important point to remember about foreign patent filing under the Paris Convention is that before you even begin the process most foreign countries require you to have already filed your U.S. patent application. This has to be done before any public disclosure of the patent. Failure to do so would mean the loss of any foreign patent filing rights you had.
Using the Paris Convention when foreign patent filing guarantees that any signatory country will give the same patent and trademark rights to citizens of foreign member countries that it gives to citizens of its own country. The foreign patent filing applications must be made to Paris Convention countries within one year after filing the U.S. patent.
The US Filing date is the priority date when foreign patent filing. This priority right means that your foreign application will be given the same consideration as the application of a citizen of a member country who filed on the same date. The one year after filing the U.S. applies only to patents. There are companies such as InventHelp that can help you out with this.
Applications for industrial designs and trademarks need to be made within six months. The one year or six months is given because it is not logistically possible foreign patent filing to file on the same date in all of the countries of your choosing.
No State emblems of any member country may be used without express prior authorization. This prohibition also applies to any governmental organizations to which each State belongs. The application will be invalidated if there is improper use of any State emblem. When you are in the process of foreign patent filing the prohibition does not apply if there is nothing to suggest to the public that a connection exists between the applicant and the concerned organization.
When foreign patent filing using the Paris Convention, keep in mind that if you are granted a patent in one State, other States are not then also obligated to grant the patent. Each State is independent of the other. It is advisable to get help with this and there are a lot of companies that are there to help for new inventors. Also, if one State does not grant the patent, another State is not allowed to then deny someone who is foreign patent filing the granting of a patent because of the refusal.