In order to analyse Patent infringement or to conclude Freedom to Operate (FTO) search, one must know how to calculate expiry of Patents or estimated expiry of pending Patent Applications. This article discusses step-wise approach for expiry calculation for India.

Amended section 53 of the Indian Patent Act, 1970 governs estimated expiry of the pending Patent Applications or expiry of Patents granted on or after May 20, 2003 (commencement of the Patent Act, 2002) or granted before but were in force on the said date. Section 53 (1) has been reproduced below for the reference.

Section 53:

(1) Subject to the provisions of this Act, the term of every patent granted, after the commencement of the Patents (Amendment) Act, 2002, and the term of every patent which has not expired and has not ceased to have effect, on the date of such commencement, under this Act, shall be twenty years from the date of filing of the application for the patent.

Explanation.—For the purposes of this sub-section, the term of patent in case of International applications filed under the Patent Cooperation Treaty designating India, shall be twenty years from the international filing date accorded under the Patent Cooperation Treaty.

(2) A patent shall cease to have effect notwithstanding anything therein or in this Act on the expiration of the period prescribed for the payment of any renewal fee, if that fee is not paid within the prescribed period or within such extended period as may be prescribed.

(3) [Omitted by the Patents (Amendment) Act, 2005]

(4) Notwithstanding anything contained in any other law for the time being in force, on cessation of the patent right due to non-payment of renewal fee or on expiry of the term of patent, the subject matter covered by the said patent shall not be entitled to any protection.

Based on the above section, step-wise approach has been given below:

Step 1: Check whether you have to calculate expiry of granted Patents or you have to calculate estimated expiry of pending Patent Applications.

  1. FOR PENDING PATENT APPLICATIONS:

Step 2: Check whether Patent Application was filed directly in India or as Convention Application or as National Phase Application through Patent Cooperation Treaty (PCT)

A1) FOR PATENT APPLICATIONS FILED DIRECTLY IN INDIA:

Step 3: Check whether application is Ordinary Patent Application or Divisional Patent Application or Application for Patent of Addition.

For Ordinary Patent Applications:

Expiry is 20 years from the filing date. Even if Patent Application was filed accompanied by provisional specification and then complete specification was filed within 12 months, expiry shall be calculated from provisional filing date. Provisional specification is considered for calculation of expiry date in India.

For Divisional Patent Applications:

Expiry is 20 years from the date of filing of parent application accompanied by either provisional or complete specification.

For Patent of Addition:

Expiry of Patent of Addition is equal to term of patent granted for main invention.

A2) FOR CONVENTIONAL PATENT APPLICATIONS:

For Convention Application which is not Divisional Application or application for Patent of Addition:

Expiry is 20 years from the date of filing in India and not from the date of priority.

For Convention Divisional Application:

Expiry is 20 years from the date of filing of parent Convention Application in India.

For Convention Patent of Addition:

Expiry of Patent of Addition granted for Conventional Application is equal to term of Patent in respect of main invention.

A3) FOR PCT PATENT APPLICATIONS:

For PCT Application which is not divisional application or Patent of Addition:

Expiry is 20 years from the International filing date/PCT date and not from priority date or Indian filing date.

For PCT Divisional Application:

Expiry is 20 years from the International filing date/ PCT date of Parent Application and not from priority date or Indian filing date.

For PCT Patent of Addition:

Expiry of Patent of Addition granted for PCT Application is equal to term of Patent for main invention.

  1. FOR GRANTED PATENT

Step 2: Check the grant date. If it's before May 20, 2003, different set of rules apply than those apply to Patents granted on or after May 20, 2003.

B1) FOR PATENTS GRANTED BEFORE MAY 20, 2003:

This is governed by un-amended section 53(1) which has been reproduced below:

Section 53 (1):

Subject to the provisions of this Act, the term of every patent granted under this Act shall-

  (a) in respect of an invention claiming the method or process of manufacture of a substance, where the substance is intended for use, or is capable of being used, as food or as a medicine or drug, be five years from the date of sealing of the patent, or seven years from the date of the patent whichever period is shorter; and

  (b) in respect of any other invention, be fourteen years from the date of the patent.

Step 3: Check whether patent was granted for application filed directly in India or as convention application in India or as National Phase through PCT

FOR PATENT GRANTED AGAINST PATENT APPLICATIONS FILED DIRECTLY AT INDIA OR AS CONVENTION APPLICATIONS

Step 4: Check the field of the invention to which patent relates.

For the inventions claiming the method or process of manufacture of a substance, where the substance is intended for use, or is capable of being used, as food or as a medicine or drug.

Expiry is the earlier of two dates, first of them being five years from the date of sealing (grant) of the patent and second being seven years from the date of the patent.

For other inventions:

Expiry is 14 years from the date of patent (date of filing of patent application).

If for any of the above two categories, expiry falls on or after May 20, 2003, expiry of patent shall be calculated according to the rules applicable to patents granted on or after May 20, 2003. It is important to note that patents which were ceased but could be restored and were restored so as to be effective on May 20, 2003, were/ are eligible for the expiry calculation according to new rules.

For Patents Granted against divisional applications, expiry depends on the filing date of parent applications.

For Patents Granted on the application for Patent of Addition, Expiry is equal to expiry of patent for main invention.

For the purpose of calculating date of filing of the applications filed directly at India, date of filing provisional specification (if filed) is considered.

FOR PATENT GRANTED AGAINST INTERNATIONAL PATENT APPLICATIONS:

Expiry is 20 years from the International filing date/ PCT date irrespective of field of the invention to which it relates.

B2) FOR PATENTS GRANTED ON OR AFTER MAY 20, 2003:

Step 3: Check whether patent was granted for application filed directly in India or as convention application in India or as National Phase through PCT

FOR PATENTS GRANTED AGAINST APPLICATIONS FILED DIRECTLY AT INDIA:

For Patents Granted against applications which are not divisional or applications for patent of addition:

Expiry is 20 years from the date of filing date. Even if Patent Application was filed accompanied by provisional specification and then complete specification was filed within 12 months, expiry should be calculated from provisional filing date.

For Patents granted against divisional patent application:

Expiry is 20 years from the date of filing of parent application accompanied by either provisional or complete specification.

For Patents granted against Patent of Addition:

Expiry of Patent of Addition is equal to expiry of Patent for main invention.

FOR PATENTS GRANTED AGAINST CONVENTIONAL PATENT APPLICATIONS:

For Patents granted against convention Application which is not divisional application or Patent of Addition:

Expiry is 20 years from the date of filing in India and not from the date of priority.

For Patents granted against Convention Divisional Application:

Expiry is 20 years from the date of filing of parent Convention Application in India.

For Patents granted against Convention Patent of Addition:

Expiry of Patent of Addition granted for Conventional Application is equal to expiry of Patent granted for main invention.

FOR PATENTS GRANTED AGAINST PCT PATENT APPLICATIONS:

For patents granted against PCT Application which is not divisional application or Patent of Addition:

Expiry is 20 years from the international filing date/PCT date and not from priority date or Indian filing date.

For patents granted against PCT Divisional Application:

Expiry is 20 years from the international filing date/PCT date of Parent Application and not from priority date or Indian filing date.

For patents granted against PCT Patent of Addition:

Expiry of Patent of Addition granted for PCT Application is equal to expiry of Patent granted in respect of main invention.

No maintenance fee has to be paid to keep Patent of Addition in force. This is applicable for any type of Patent of Addition irrespective of Patent of Addition is granted against Patent Application filed directly at India, or as Convention Application or as Patent of Addition. However, if Patent for main invention is revoked, patent of addition can be converted into independent Patent. In such a case, maintenance fees/ renewal fee has to be paid in respect of Patent of Addition turned Independent Patent.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.