In March 2024, India’s Patents (Amendment) Rules introduced a formal mechanism for claiming the statutory grace period under Section 31 - via Rule 29A and Form 31. Prior to this, inventors had to rely on affidavits or ad hoc submissions to argue that a public disclosure should not count as prior art. Now, a standard form ensures greater clarity and procedural certainty.
Below is a detailed guide to Form 31 - its legal foundation, eligibility, how to fill it, timeline, key risks, and strategic advice.
Legal Foundation & Why Form 31 Was Introduced
Section 31: Grace Period in the Patent Act
Under Section 31 of the Patents Act, certain public disclosures of the invention made before filing do not prejudice novelty if:
The invention was displayed at an industrial or other exhibition notified by the Central Government, with inventor’s consent; or
The disclosure was by the inventor or someone deriving title; or
The disclosure occurred through an unauthorized use or disclosure during that exhibition; or
The invention was presented before a learned society (or published in the “transactions” of such society) with inventor’s consent.
These exceptions essentially provide a 12-month “grace period” for qualifying disclosures.
Before 2024, there was no prescribed form or fee for claiming this - applicants needed to explain in their specification or file affidavits and rely on Controller’s discretion.
Rule 29A & Form 31 (2024 Amendment)
The 2024 Amendment inserted Rule 29A into the Patents Rules, 2003, which states:
“An application to avail the period specified under Section 31 shall be filed in Form 31, along with the fees specified in the First Schedule.”
Thus, to claim the benefit of Section 31, an applicant now must file Form 31 (with evidence and fee) as part of the patent application process.
Multiple sources confirm that the new form is mandatory when claiming grace period, and that an official fee (such as ₹500 for natural person/small entity and ₹2,500 for others) is prescribed.
Accordingly, Form 31 is the procedural gateway to avail the grace period in India under the revised rules.
When & Why to Use Form 31
You would use Form 31 in the following scenario:
Your invention has already been publicly disclosed, displayed, published, or used in a manner falling within one of the Section 31 exceptions (e.g. at a notified exhibition, in learned society proceedings, or public display) before you file the patent application.
You still wish to file a patent application and protect against that prior disclosure being held as anticipatory prior art.
You are within 12 months from the date of that disclosure - to fall within the grace period.
You want a clean, formal record of your claim (rather than informal affidavits).
In short: if your disclosure happened before your intended filing, and you want to preserve novelty under Section 31, you must file Form 31 with your application.
Important caveat: The grace period is an exception, and the burden of proof lies on the applicant to show the disclosure qualifies. The Controller may scrutinize evidence (notifications, exhibition records, consent, etc.).
Contents & Format of Form 31
You can download the official Form 31 - Grace Period template from the IPO website.
Key fields and how to fill them:
Field | What to Provide / Note |
Name, address, nationality, application number | Identify the applicant(s), address, and the patent application number (or provisional if applicable) |
Claiming grace under which provision | Tick/select one or more of: Section 31(a), (b), (c), (d) - whichever relates to your disclosure type |
Details & documentary evidence | For each selected provision, supply evidence and date(s): • For 31(a): date of display, exhibition notification, inventor consent, etc. • For 31(b): sequence of disclosure following display • For 31(c): evidence of unauthorized use during display • For 31(d): name of learned society, date of reading, publication in transactions, consent. |
Declaration / undertaking | Undertake that the complete specification is filed within 12 months of disclosure and that all the evidence is genuine. |
Signature, date, place | Signed by applicant or authorized agent. |
You may need to attach:
The notification of the exhibition (if applicable), or record showing that the exhibition was notified by the Central Government
Exhibitor consent or inventor’s consent
Publication copy (if published)
Proof of publication in society “transactions”
Affidavits or declarations supporting use, display, or consent
Chronology / timeline of disclosure
If multiple disclosures are involved (e.g. display then publication), you may combine claims under different sub-sections, but ensure evidence supports each.
Timing, Fee & Procedure
Deadline: The application (i.e. your patent application along with Form 31) must be filed within 12 months of the public disclosure (i.e. your disclosure event). If you miss that window, the grace period cannot be claimed, and the disclosure may kill novelty.
Fee: The Rules specify a fee in the First Schedule for Form 31. One publication indicates ₹500 (for natural persons / startups / small / educational entities) and ₹2,500 (for others).
Filing: Form 31 must be filed along with the patent application (or as part of it) so that the claim is recorded from the outset. Delayed filing of Form 31 after filing may weaken your position.
The Controller will consider the documents and evidence. If satisfied, the prior disclosure will not be held as anticipating prior art under Section 31.
Risks, Limitations & Strategic Considerations
Strict interpretation: The Controller may reject claims under the grace period if evidence is weak or display is not in a government-notified exhibition. Courts and IPO practice are likely to interpret Section 31 narrowly.
Exhibition notification needed: The exhibition must have been officially notified in the Official Gazette (or applicable by government notification) for sub-clause (a). If not, your display may not qualify.
Learned society terms ambiguous: The statute uses terms like “learned society” and “transactions” which are not precisely defined - their eligibility may be contested.
Limited relief: Grace period does not cover all public disclosures - only those falling under Section 31’s enumerated categories. General journal article publications may not qualify unless in a “learned society transaction” with consent.
Burden of proof: You must convincingly document the disclosure timeline, consent, and link to the invention. Missing or weak documentation can lead to refusal.
Not a blanket safe harbour: Best practice is still to file before disclosure. The grace period is a safety valve, not a strategy.
Drafting & Practical Tips
Before any disclosure, plan your patent filing timeline. If you must disclose, ensure exhibitions/publications are formally notified and consent is documented.
Maintain a detailed disclosure log: dates, documents, consent forms, exhibition catalogues, photographs, press coverage, etc.
Use Form 31 at the time of filing - do not rely on retroactive submissions.
If multiple disclosure events exist, include all in the chronology and evidence mapping to relevant sub-sections.
Keep the description in your specification consistent and broad enough to cover what you disclosed.
Engage experienced patent counsel early to assess whether a given disclosure will qualify under Section 31.
Monitor IPO guidelines and jurisprudence on interpretation of Rule 29A/Form 31, as this is a relatively new regime.
