Like any other patent application, a provisional patent application is effective to stop the clock relative to so-called statutory bars and immediately upon filing a provisional patent application you can say you have a “patent pending.” Perhaps most importantly, now that the United States has become a first to file country and abandoned our historic first to invent ways it is critically important to file a patent application as soon as practically possible. Filing a provisional patent application that adequately describes the invention will establish priority and satisfies the need to act swiftly under first to file rules. A well prepared provisional patent application is your best friend in a first to file world.