While filing for a patent in India, the claim and specification must be clear and precise as they determine the monopoly claimed. Others should “know the exact boundaries of the area within which they will be trespassers”.[1] It may be necessary to modify a claim, for example, to correct a mistake, overcome objections, or bring consistency in claims across various jurisdictions.

Such amendments are a common aspect of patent proceedings. The provision to amend a patent claim under patent law in India has its roots in  section 17 of the Indian Patents and Designs Act, 1911  This provision allowed an applicant to amend a specification at any time by submitting a written request to the Patent Office. Noting the broad ambit of the provision, the Ayyangar Committee Report highlighted that “where the invention which emerges as a result of an amendment is different from that which was the subject matter of the specification as originally accepted, such an amendment should not be permitted”[2]. This recommendation formed the basis of sections 57 to 59 of the Indian Patents Act 1970 (the ‘Act’), which now governs the amendment of claims in India.

Amending Patent Claims under Indian law

Section 57 of the Act allows an applicant/patentee to amend an application for a patent, the complete specification, or any related document at any time. This can be either on his own accord or to comply with the directions of the Controller. This provision can only be used where an application exists and not where the application or patent has lapsed.[3]

Section 58 of the Act provides that the High Court or Appellate Board may allow an applicant/patentee to amend the claim or specification instead of revoking a patent which is found to be invalid.

Section 59 of the Act provides that amendments for the incorporation of an actual fact can be made in three ways[4]:

  1. Disclaimers – to limit or narrow the scope of a claim;
  2. Correction – to correct obvious mistakes or clerical errors; and
  3. Explanation – to make a claim or description clear and unambiguous.

Additionally, the amendments must not expand the scope of the claim or add additional subject matter and should be supported by the original specification or claim.[5]  For example, in AGC Flat Glass Europe v. Anand Mahajan and Ors.,[6] the Delhi High Court permitted the amendment after the grant of the application, where a limitation from the description was included in the claim, on the ground that it served to clarify rather than broaden the scope of the claim.

Support for an amendment can also be in the form of drawings in the original claim. In Prism Cement Ltd vs The Controller of Patents and Designs [Order No. OA/7/2016/PT/MUM], an amendment changing the word ‘channel’ in the original claim to ‘open channel’ was permitted on the ground that it was already a ‘part and parcel of the original disclosure’, was made by way of  ‘explanation’ and did not introduce any new matter or broaden the scope of the claim.

Amendments to add new dependent claims often receive objections from the Controller under s 59 of the Act. However, in Tony Mon George, the Regents of the University of Michigan v. Controller of Patents and Designs[7], the IPAB explained the difference between inserting a new claim and inserting a dependent claim. A dependent claim may be permissible as it merely qualifies or limits the scope of the already-defined subject matter of the original claim.[8]

The conduct of the applicant/patentee also plays a vital role in assessing an application for amendment. A delay in seeking an amendment can be grounds for refusal unless the applicant/patentee can provide evidence of reasonable grounds for the delay.[9] Evidence of bad faith or unfair conduct can also lead to a refusal of the amendment.[10]

In Boehringer Ingelheim International v. The Controller of Patents,[11] an order of the Controller refusing a divisional application was challenged before the Delhi High Court. The claims in the divisional application were based on amendments rejected under s 59 on the ground that they were beyond the scope of the original claims. An essential factor of filing a divisional application is that its claims must be based on the claims filed in the parent application. In the present case, the divisional application claims were based on the disclosure of the parent application. Rejecting the application, the court held that if the subject matter is merely disclosed in a patent specification but not claimed, that subject matter is considered as ‘disclaimed’ and thus unavailable for further claiming.

Deleting patent claims under Indian Law

Before the introduction of the Patent Amendment Rules 2016, an Indian National Phase application was required to be filed with a complete specification identical to that filed with the International application. The issue with this was the associated costs. In India, there is an official fee for every claim above ten claims and every page above 30 pages. Further, prior to the 2016 amendment, the deletion of claims was not allowed at the time of entering the national phase in India. Therefore, while entering the India National Phase, the applicant had to file the application with the same set of claims filed in the International application, possibly attracting excess claim fees, including fees for claims the applicant did not wish to pursue in India.

Following the amendment, under the proviso to Rule 20(1) of the Patent Amendment Rules 2016, an applicant can delete claims during the Indian National Phase entry. Deletion is primarily useful where part of the claims are not patentable in India. This eliminates the financial burden and the lengthy process of filing the claims and then making a separate application under s 57 to delete the claims. This provision has a prospective effect and applies only to national phase applications filed after the rules came into effect on 16 May 2016.


The provisions governing the amendment of claims are vital as they allow applicants to correct or explain the scope of the monopoly claimed. Sections 57 and 59 of the Act provide an important mechanism to ensure that the process of amending a claim is not abused to expand the scope of claims unjustly.  However, an overly-strict approach to assessing amendment applications can lead to genuine applications being disallowed. To combat this, the IPO should consider issuing guidelines under s 59 to ensure a uniform and commercially viable approach.

[1] Tony Mon George – The Regents of the University of Michigan v. The Controller General of Patents, Designs & Trademarks & Anr (OA/48/2020/PT/DEL)

[2]  at para 553

[3] Nippon Steel Corp. v. Union of India (W.P. (C) 801 of 2011, Delhi High Court) at [24]

[4] s 59(1), Patents Act 1970

[5] Ibid

[6] I.A. No. 13519/2007 in CS (OS) No. 593/2007, Delhi High Court

 [7] OA/48/2020/PT/DEL

[8]Ibid at 35.4 and 36

[9] AGC Flat Glass Europe v. Anand Mahajan and Ors. (n 6); Enercon India v. Aloys Wobben (ORA No. 9/2009/PT/CH, ORA No. 20/2009/PT/CH and ORA/41/2009/PT/CH

[10] Enercon India v. Aloys Wobben, ORA/6/2009/PT/CH

[11] C.A. COMM.IPD-PAT 295/2022 & I.As.10369-70/2022

Anand Barnabas

Practice Head - Patent - Mechanical & Automotive

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