The US Patent Office recently transitioned from a first-to-invent basis for deciding between competing inventors trying to patent the same invention, to first-to-file system starting. The United States allows inventors to file a provisional patent application to establish a patent filing date, as long as the non-provisional patent application is filed within a year of the provisional patent application filing.
The provisional application can have less detail than a non-provisional patent application, making it considerably less expensive to file than a full application. In many cases the provisional patent application is prepared by the inventors with minimal supervision by a patent attorney or patent agent, however this introduces some risk that the provisional patent application might not be detailed enough to provide an earlier priority filing date.
The biggest risk of a provisional patent application is that inventors might rely on the early priority date, and not follow through quickly with a non-provisional application. The provisional application provides an earlier priority filing date only if the final patent claims of the full patent application are well supported by the provisional patent application. The inventors could lose patent protection on their invention if they delay filing the full patent application, and the USPTO determines that the provisional patent application does not provide enough information to support the final patent application claims. As a result, a non-provisional patent application should be filed by the inventors as soon as possible in order to protect the invention.
The United States has a two-tier pricing structure for patent applications, where small entity fees are about half as much as for large entities such as most corporations. The provisional patent application filing fee for a small entity is a few hundred USD, not including possible payments for patent search, patent drawings, and the services of a patent agent or patent attorney which can be much more expensive.