Patent Application Number Versus Publication NumberAlso called the patent's serial number, patent applications all receive an application number from the U.S. Patent and Trademark Office (USPTO). If the application is approved and the invention is officially patented, the patent will have a full patent number.Application numbers follow this format: XX/XXX,XXX with a forward slash after the first two digits. The full patent number follows this format: X,XXX,XXX. If a patent is published, it will also receive a publication number with the following format XXXX/XXXXXXX.On an official U.S. patent cover, the format of the patent number would also have a letter and number at the end, for example: US 7,493,599 C2.