Practice Area

Patent Services

A patent gives an inventor the exclusive right to make, use and sell an invention for 20 years from the date of filing, provided it clears the tests of novelty, non-obviousness and industrial application. Biswajit Sarkar guides clients through every stage of that process, from the first search to renewal decades later.

Patent services at Biswajit Sarkar

Our patent team combines rigorous prior-art search, careful drafting and prosecution strategy with the litigation experience needed to defend a granted patent once it matters most.

Stage 01

Patent search & prior-art review

A thorough search against India's patent database is what tells an applicant whether an invention is genuinely new. It also does the practical work of shaping the claims that eventually go into the application, well before drafting starts.

8categories a search result returns, from priority date to classification and applicant details
3columns of detail on a selected result: bibliographic data, specification and status
Freeto run a search through India's public patent database, published or granted
Stage 02

Patent registration process

Not every idea qualifies — Section 3 of the Patents Act, 1970 sets out subject matter that cannot be patented, so it pays to know the exclusions before drafting begins. From there, registration runs through six connected stages.

  1. 01

    Search & drafting

    A prior-art search establishes whether the invention meets the novelty bar, then the application — claims, background, description, drawings and abstract — is drafted to disclose the invention clearly and defensibly.

  2. 02

    Filing

    Filed through Form 1, generating a receipt with the application number. An early-stage invention can instead be filed as a provisional application, which locks in a priority date and leaves 12 months to submit the complete specification. Start-ups and small businesses may use Form 28.

  3. 03

    Publication

    Rule 24 keeps an application out of public view for 18 months from filing or priority. An applicant who doesn't want to wait can request early publication on Form 9 under Section 11A(2), which typically publishes within a month.

  4. 04

    Examination

    Examination isn't automatic — a request must be filed on Form 18 within 48 months of filing, or expedited under Rule 24C for a higher fee. The Controller assigns an examiner to assess novelty, inventive step and industrial applicability, producing the First Examination Report.

  5. 05

    Responding to objections

    Objections raised in the First Examination Report are answered with a written response, and a physical hearing can be requested if the applicant wants to argue the point directly.

  6. 06

    Grant & publication

    Once every objection is addressed, the patent is granted and published in the patent journal — opening a 12-month window in which any interested person may file a post-grant opposition.

Stage 03

Patent opposition

Used properly, opposition is a cost-effective check against weak or overreaching patents, without resorting to a full revocation action. India runs the process at two distinct stages, each with its own rules and grounds under Section 25 of the Patents Act.

Section 25(1)

Pre-grant opposition

Open to any third party, free of charge, once the application is published and before the patent is granted. Grounds include wrongful obtaining of the invention, prior publication or claiming, anticipation by local knowledge or use, lack of inventive step, insufficient disclosure and non-disclosure of a foreign application, among others set out in clauses (a)–(k).

  • Filed on Form 7(A) with supporting statement and evidence
  • Only available once examination has been requested
  • Applicant replies with evidence within 3 months of notice
Section 25(2)

Post-grant opposition

Filed by an interested party within 12 months of the grant being published, on largely the same grounds as a pre-grant challenge. A three-member Opposition Board — chaired by a Controller nominee — reviews both sides' evidence and recommends whether the patent should be maintained, amended or revoked.

  • Written statement and evidence filed in duplicate
  • Patentee must reply within 2 months or risk revocation
  • Following Cipla v. Union of India, the Board's recommendations are shared with both parties before the final hearing
Stage 04

Patent renewal

A patent's 20-year term only holds if the renewal fee is paid on schedule. Miss it, and the invention falls into the public domain — with no special form standing between a patentee and that outcome, only a fee paid directly to the Controller.

Stage 05

Patent infringement

Infringement is the unauthorised use or sale of a patented invention, and in most cases the use needs to be commercial in nature. India recognises two forms of infringement and a set of remedies proportionate to how clearly it can be shown.

Type

Direct infringement

Occurs where a product on the market is similar or identical to a patented one, and it is being used or sold commercially without the patent holder's permission.

Type

Indirect infringement

Occurs without deliberate intent to infringe — the overlap with the patented invention arises incidentally rather than by design.

CustomsA patent holder can approach the collector of customs to block infringing goods at the border
InjunctionAn interim injunction can follow prima facie evidence, becoming permanent once proved at trial
DamagesAwarded where the infringer is shown to have known of the patent at the time of infringement
Stage 06

Filing internationally through the PCT

The Patent Cooperation Treaty, administered by WIPO, lets an applicant protect an invention across more than 145 contracting states through a single international application rather than filing separately in each one.

  1. 01

    File with a Receiving Office

    Filed with the Indian Patents Office (Delhi, Mumbai, Kolkata or Chennai) or directly with WIPO's International Bureau, using Form PCT/RO/101 with description, claims, abstract and drawings in English or Hindi, submitted in triplicate with the prescribed fees paid within a month.

  2. 02

    Filing date & distribution

    Once the Receiving Office confirms the required details, it accords the international filing date — treated as the actual filing date in every designated country — and distributes a home copy, a record copy to WIPO and a search copy to the International Searching Authority.

    Checklist

    Documents & information to have ready

    • Name, address and nationality of the applicant and inventor
    • Title of the invention, plus the priority application number and filing date
    • An address for service in India
    • Power of attorney, once a patent agent is appointed
    • An instrument of assignment, if the applicant isn't the inventor
    • Verification for any document filed in translation
  3. 03

    International search

    The ISA produces an International Search Report identifying prior art that could affect patentability, along with a Written Opinion on the invention's potential patentability. Applicants can choose among WIPO-recognised offices to conduct this search.

  4. 04

    Publication

    WIPO publishes the international application together with the Search Report, 18 months after the priority date.

  5. 05

    Optional preliminary examination

    An applicant may request an international preliminary examination, producing an International Preliminary Report on Patentability; if they don't, the earlier Written Opinion is published in its place. Amendments can follow the examining authority's written opinion.

  6. 06

    National phase entry

    Before 30–31 months from the priority date, the applicant files for grant in each country where protection is wanted — in India, the national-phase application is due within 31 months of the priority date, using the international filing date as the effective filing date.

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