A patent is granted to an inventor for a scientific invention. A patent is granted in a country under the specific act and rules. On fulfilling the criteria of patentability such as novelty, inventive steps and industrial applicability, a patent is granted to an inventor. A patent is a right given to an inventor to exclude others from manufacturing, selling, offering to sell, licensing or practicing any prohibited act which will account to patent infringement.
On issuance of a patent to an applicant, a number is entered in the register and it is given to the issued patent, generally known as patent number. The system of patent number is different is most of the countries. For example, in the USPTO system, the patent number issued to a patent completely a new number series which is different from the application number of the patent. Whereas in EP, the patent number and patent application number is different only in the kind code attached to it. For a granted patent it appears with a code "B" and for a patent application, the kind code is "A" but the number issued to a patent application is not changed when it is granted. In some countries a patent number or application number is accompanied with a kind code which indicates the latest amendments to the prosecution state of the patent application.
Patent Application Number
For an Indian patent application the number issued is in the order No./Jurisdiction of the patent office/year i.e. XXXX/DEL/2011 whereas granted patents are given in different series of number. Example of Patent number and published patent application number is as follows:
A patent number does not change and it is permanent once issued for an invention. On the other hand a patent application number is not permanent, it is no longer valid once the patent is granted and issued a number.