In order to keep a patent in force, renewal fee has to be paid to the Indian patent office before the expiration of the second year for the advancing year. A patent is granted for a period of 20 years from the date of filing of the application and International filing date in case of PCT National phase application. The renewal fee is paid to the Indian patent office 3rd Year onwards in advance. If the patent is granted later than 2 years from the date of filing of the application, the due fees have to be paid within a period of 3 months from the date of recording of the patent in the register. If the patent is granted before the expiry of the two years from the date of filing of the application, the first renewal fee becomes due in respect of the third year, which has to be paid before the expiration of the second year. There is no separate form to be submitted for renewal. An applicant can directly pay renewal fee by making a request to the controller of the patent.