Grace Period for Prior Disclosure in India: Form 31

Explainer · Patents · Last verified October 2026

Updated for 2026 · Claw Editorial

A founder shows a prototype at an exhibition. A scientist reads a paper before a learned society. Weeks later someone says: "You may have just destroyed your patent." In most countries that fear is real, because a patent needs novelty and your own earlier disclosure can count against you. India gives a limited relief. Section 31 of the Patents Act, 1970 protects certain disclosures if you apply within 12 months, and since the 2024 rule changes you must claim it on Form 31. The fee is Rs 500 for a natural person, startup, small entity or educational institution, and Rs 2,500 for others. This page explains what is covered, what is not, and what to do next. Last verified October 2026.

01The problem: your own disclosure can count against you

A patent is granted only for something new. If the invention was already public before you filed, it is called "anticipated", and the application can be refused or the patent later revoked. The rule does not care who made it public. Your own talk, paper or product demo counts the same as a rival’s.

This hurts researchers, startups and universities the most. They publish, pitch and demo early, often before a lawyer is involved. A grace period is a safety net for that mistake. But in India the net is narrow, and many people assume it is wider than it is.

02What section 31 covers

Section 31 lists specific situations in which an earlier disclosure is not treated as anticipation, provided the patent application is filed within 12 months. In simple terms they are:

• Exhibition display: the invention was shown at an industrial or other exhibition notified by the Central Government, or was published as a result of that display. The 12 months run from the opening of the exhibition.
• Learned society: the invention was described in a paper read before a learned society, or published in its transactions. The 12 months run from the reading or publication.
• Public working for a reasonable purpose: the invention was publicly worked, by or with the consent of the true and first inventor, for a purpose reasonably needed to establish how it works. This limb is read narrowly.

The word "notified" matters. A trade fair counts only if the Central Government has notified it for this purpose. A random conference or a startup demo day usually does not.

Related but separate: section 30 deals with communication of the invention to the Government, and sections 29 and 32 deal with prior publication and prior use. This page stays on the section 31 grace period.

03What it does not cover

This is where most mistakes happen. Section 31 is not a general "disclose now, file within a year" rule like the one some other countries use.

• Websites, blogs and social media: posting your invention online is not one of the listed cases. Treat it as a full public disclosure.
• Sales and commercial launch: selling or offering the product is not covered by the grace period.
• Investor pitches and press: a news article or a public pitch is not a notified exhibition or a learned society paper.
• Other countries: a grace period in India does not give you one abroad. Many countries have no grace period, or a shorter one. Check each country before you file there, and see the WIPO material in the sources below.

A grace period is a safety net, not a plan. File first whenever you can.

Also note that a disclosure by someone else, without your consent, is a different question under the anticipation rules and should be checked on its own facts.

04Form 31: how to claim the grace period

Earlier, applicants simply argued the grace period if a disclosure came up during examination. Under the Patents (Amendment) Rules, 2024, a formal step was added. Rule 29A of the Patents Rules, 2003 says an application to avail the period under section 31 must be made on Form 31, with the fee in the First Schedule.

Keep the evidence ready from day one: the exhibition notification, the programme or invitation, the paper or abstract as presented, the date, and proof you were the person who disclosed it or that it was done with your consent.

Fees change from time to time, so confirm the current amount on the official IP India site before you pay. The figures here were last verified October 2026.

05A worked example

A university lab shows a new water filter at an exhibition that the Central Government has notified. The exhibition opens on 10 January. The lab has not filed a patent.

• If the lab files its application within 12 months of 10 January, and claims the benefit on Form 31 with evidence, the display is not treated as anticipating the invention.
• If the lab also posted a detailed blog about the filter in February, that blog is not covered. It can still be cited as prior art.
• If the lab wants a patent in another country, it must check that country’s own rules. The Indian grace period does not travel.

The lesson: the grace period saves one specific disclosure. Everything else you did in public still counts.

06Practical steps if you have already disclosed

1. Write down every disclosure: date, place, audience, what was shown, and any web copy.
2. Sort them: which fit section 31 (notified exhibition, learned society) and which do not.
3. Count 12 months from the earliest qualifying date and set an internal deadline well before it.
4. File the application and Form 31 with evidence, paying the right fee (Rs 500 or Rs 2,500).
5. Plan overseas filings separately, because other countries may already treat the disclosure as fatal.

Opposition and challenge risk is a separate topic. If your patent may face a challenge later, read pre-grant and post-grant patent opposition in India. For another deadline that can be restored after it is missed, see design renewal and restoration in India. For tools that help manage patent deadlines, see pharma IP software in India.

This page is general information, not legal advice. Disclosure facts vary, so speak to a registered patent agent or advocate before you rely on the grace period.

07Where Claw fits

Claw is an all-in-one legaltech platform for Indian advocates, law firms, and corporate legal teams, combining AI-based case search, an AI legal assistant (Legal GPT), case management, and compliance automation across all Indian courts and tribunals.

A grace period claim rarely stays on paper. It surfaces when an application is objected to, or when a granted patent is later attacked on the ground that the inventor disclosed too early, and that fight runs through the Patent Office and the High Courts. Claw lets you research how courts have read anticipation and prior disclosure, searching 30 crore+ judgments with results in under 5 seconds, with Supreme Court coverage from 1950 and High Courts from 1990. It also tracks cases, orders and hearings across 9,102 courts, benches and forums, so you can follow a live patent matter by party or advocate name and see how a bench has treated a disclosure point before you rely on section 31.

Claw does not use customer documents to train AI models. Create a FREE Claw account to research prior disclosure and patent decisions and track your matters by party or advocate name. To search the wider body of law, see case search across Indian courts.

08Sources and further reading

Check these primary sources before you rely on any date, rule or fee. Last verified October 2026.

• Office of the Controller General of Patents (IP India), Act, Rules and forms: ipindia.gov.in
• The Patents Rules, 2003 (Rule 29A and the First Schedule fees): Patents Rules PDF on ipindia.gov.in
• Statute text and case law: indiankanoon.org
• WIPO, for grace period rules in other countries: wipo.int
• Claw: clawlaw.in

Law firm explainers were also used to cross-check the Form 31 fee: Rs 500 and Rs 2,500 for online filing. Always confirm against the official fee table.

09Frequently asked questions