When should a Provisional Patent Application be filed in the United States?

When should a Provisional Patent Application be filed in the United States?

Sometimes a decision is made not to file a utility patent application. In such cases, a provisional application may be filed instead.  Provisional applications are frequently filed where the inventor has an invention that he wants to protect but the invention in not fully developed. The provisional application gives the inventor an opportunity to start the patent process earlier in the development of the invention. Provisional applications are particularly useful where an inventor is giving a speech or other type of presentation, such as in a trade show where the invention will be revealed and the inventor wants to protect the invention, but there is not enough time to file the regular patent application. In such instances a provisional application may be filed. The provisional application must have a written description of the invention just like the usual utility patent application. The Patent Office fee for a provisional application is significantly less than the filing fee for a traditional patent application. A provisional patent application is not a substitute for a utility patent application.  The provisional application merely postpones the time for filing a patent application by one year. The complete patent application must be filed within one year of the filing of the provisional application.

If a patent application has been filed in China and the application is later filed in the United States, a provisional application would not be filed. A regular patent application should be filed instead of a provisional application in order to claim the benefit of the Chinese application.