Innovate Articles

"Not as Straightforward as Before" - Patent Post-Grant Amendment in Singapore

By Gerald Koh



In general, post-grant amendments may be used by a patentee to narrow the scope of protection, for example, in order to align a patent with corresponding patents in other jurisdictions. Typically, such post-grant amendments are sought prior to enforcing a patent or during infringement proceedings when objections to patentability are raised by opponents. 

Prior to 2016, post-grant amendment practice before the Intellectual Property Office of Singapore appeared relatively straightforward. Namely, allowance of post-grant amendment just depended on fulfillment of the statutory requirements in Section 84(3) of the Singapore Patents Act:

“No amendment of the specification of the patent shall be allowed … if it –

(a) results in the specification disclosing any additional matter; or

(b) extends the protection conferred by the patent”.

In 2016, however, the Intellectual Property Office of Singapore updated its guidelines on the assessment of post-grant amendments. Consequently, in addition to Section 84(3) of the Singapore Patents Act, post-grant amendments will also be assessed based on the following non-statutory discretionary criteria:

  1. Whether relevant matters are sufficiently disclosed;
  2. Whether there was any unreasonable delay in seeking amendments; and
  3. Whether the patentee has gained an unfair advantage, obtained by delaying amendments which are known to be needed.

Regarding criterion (2) on “unreasonable delay” in particular, the Singapore High Court in Warner-Lambert Company LLC v Novartis (Singapore) Pte Ltd [2016] SGHC 106 [1] listed the following three points that must be considered in assessing “unreasonable delay” ([99]-[114]):

  1. The period of delay need not be long to be considered undue;
  2. A delay may not be held against the amending party if he was able to provide a reasonable explanation; and
  3. The time when the amending party first becomes aware of the need to amend starts the “clock” running.

On point (c), the Singapore Court of Appeal in Warner-Lambert Company LLC v Novartis (Singapore) Pte Ltd [2017] SGCA 45 [2] explained that actual or constructive knowledge of the need to amend will start the “clock” running. Further, there is no fixed threshold after which delay is deemed “unreasonable”. Rather, the question of whether a delay is reasonable or not is determined by the amending party’s ability to give plausible explanation for the entire period of inaction.

Accordingly in Singapore, whether, when and why amendments were made to the claims in any foreign corresponding applications of the same patent family (“parallel applications”) to address patentability objections in any parallel applications, may have a bearing on the allowance of post-grant amendments in a Singapore patent. Such allowance or otherwise may, in turn, affect the chance of maintaining a valid patent in Singapore during any post-grant proceedings such as revocation or infringement.


In view of the aforesaid, it would be advisable for you to take a proactive stance in monitoring your Singapore patent portfolio for any need to seek post-grant amendments. In this regard, you may wish to consider taking the following actions.

For all granted Singapore patents in your portfolio:

Identify Singapore patents where prior art relevant to novelty and/or inventive-step have surfaced post-grant, for example, through the prosecution process of any parallel applications. It is advisable to seek a Singapore patent agent’s advice immediately to determine whether post-grant amendments need to be made in view of the identified prior art.

For all pending Singapore patent applications which have parallel applications still pending:

You may wish to delay the grant of the patent to the extent it is practicable, by holding off the request for examination of your Singapore patent application. This may be done by applying for an extension of time to the deadline for requesting examination or by filing a Singapore divisional application (and allowing the parent application to be abandoned) to reset the deadline for requesting examination. In this manner, you may preserve the chance to file pre-grant amendments as and when necessary, based on prior art which surfaces in any parallel applications.

Typically, filing a Singapore divisional application would be the most effective, as shown in the table below:


Requesting for an extension of time


Filing a divisional application


Making post-grant amendment

Amount of extra time to consider amendments pre-grant

Up to 18 months more by holding back the request for examination


Deadline to request for examination would “reset” from the lodgement date of the divisional application

(For a request for substantive examination, 36 months from the lodgement date)



Approximate official fees [3]


145 USD per month


115 USD


905 USD


 [1] Warner-Lambert Company LLC v Novartis (Singapore) Pte Ltd [2016] SGHC 106 

[2] Warner-Lambert Company LLC v Novartis (Singapore) Pte Ltd [2017] SGCA 45

[3] Note: All fees are approximate and are converted from SGD based on the conversion rate of 1 USD = 1.38 SGD

Gerald Koh graduated from the University of Buckingham, UK, in 1994 with an LLB and has been called to the bar in Singapore, England and Wales. He is a Singapore qualified intellectual property (IP) lawyer and a registered Singapore Patent Attorney with over 17 years’ experience in patent prosecution and litigation at a leading Singapore law firm before joining Viering Jentschura & Partner where he now serves in his capacity as a Singapore Patent Attorney.