According to the United States Patent and Trademark Office, patent lengths depend on the type of patent. They also vary depending on the date the application was filed or the patent was granted.Continue Reading
The Patent and Trademark Office reports that patents issued before and after June 8, 1995, may be valid for different lengths of time. Utility and plant patents granted after this date end 20 years from the date the application was filed. Patents issued before this date are valid either for 20 years from the date of application or 17 years from the date the patent was granted. The length of time that is longer is the length of the patent.
According to LegalZoom, design patents are valid for 14 years from the date the patent is granted and are not renewable.Learn more about Law