Duration and maintenance of patent

(1) Subject to sub-section (2), a patent shall expire 20 years after the filing date of the application therefore. (2) In order to maintain a patent or patent application, the owner of the patent or the applicant shall pay in advance to the Registrar for each year starting one year after the filing date of the application for the grant of the patent, the prescribed annual fee. (3) Where the period prescribed for the payment of the annual fee expires and payment of the said fee has not been made, the Registrar shall give the owner of the patent or the applicant, as the case may be, a period of grace not exceeding six months, within which he must pay the annual fee. (4) The owner of the patent or the applicant, as the case may be, shall, when paying the annual fee in accordance with sub- section (2), also pay, to the Registrar, the surcharge prescribed for late payment. (5) A patent shall lapse or a patent application shall be deemed to have been withdrawn if the annual fee is not paid in accordance with the provisions of this section. (6) If a patent ceases to have effect under this section, the Registrar shall enter the lapse in the Register and publish it in the Journal.