What is a provisional patent application?
A provisional patent application is an inexpensive and simpler version of a full patent application which can be filed with the PTO as a type of place holder. This patent application contains a full disclosure of the invention, explaining what the invention is and how it works, but does not have to contain the detailed claims which indicate precisely what elements of the invention the inventor seeks patent protection for. Because these applications are less involved than full patent applications, they are cheaper to prepare and easier to file. Also, the PTO filing fees are cheaper for a provisional patent application than for a full patent application.
A provisional patent application will not become a full patent without further actions taken by the inventor. Specifically, within 12 months of filing the provisional application, the inventor must file a non-provisional patent application, which is a full patent application. If this is done in time and the patent is ultimately granted, the patent will be considered filed as of the date when the original provisional application was filed. This is often important with regard to the issue of patent priority. If, however, the inventor allows 12 months to pass without filing a follow-up application, the original provisional application expires. Often times, an inventor will file a provisional application and then allow it to simply expire, because the inventor decides not to seek patent protection for the invention in question.