Section 33 of the Patents Act, 1970
Anticipation by use and publication after provisional specification
Section 33 protects an application against use or publication of the invention that happens after the provisional specification has been filed.
Official legal text
The verbatim statutory text of this provision is reproduced from the official source and checked by our legal reviewer before it is published here. Until that check is complete for this page, read the exact wording directly from the official source linked below — it is the only version that governs.
This explanation is written for clarity, not for citation. The official statutory text and any Gazette notification in force on your date govern, and they prevail over anything said here.
What this section says, in plain language
A provisional specification is an early filing under section 9. It describes the invention but does not need claims, and it fixes a date. The applicant then has twelve months to file the complete specification, which contains the full description and the claims. That gap exists so that inventors can secure a date early and refine the invention afterwards.
The gap creates a practical problem. During those months the inventor is rarely silent. There are investor meetings, customer pilots, supplier discussions, conference posters and sometimes a journal paper. Under ordinary novelty rules, any of that could later be cited against the complete specification. Section 33 closes that gap. Use or publication of the invention in India during the period after the provisional specification is filed cannot be used to refuse the grant, and cannot be used to revoke or invalidate the patent afterwards.
The protection has an important boundary. It attaches to the invention as described in the provisional specification. If the complete specification adds new matter that the provisional never disclosed, that new matter takes the later date under the priority rules in section 11, and disclosures made in the interval can be cited against it. This is why a thin, rushed provisional is expensive. Many applicants file two pages, develop the invention substantially over the next year, disclose the developed version to customers, and then discover that the part they care about has no shelter.
The section also deals with convention applications. Where an application is made in India on the basis of an earlier application filed in a convention country, use or publication in India after the date of that basic foreign application is treated in a comparable way, so the applicant is not defeated by activity in India during the priority year.
Two practical points follow. First, write the provisional as though it will have to carry the whole invention, because it may have to. Second, remember that section 33 speaks about use and publication in India. Foreign patent offices apply their own law to the same disclosures, and a disclosure that is harmless here can be fatal elsewhere.
Why this section matters
Any applicant who files a provisional specification first, especially startups, student inventors and research groups who need to talk to investors and customers while developing the invention.
It applies throughout the period between the provisional specification and the complete specification, and again whenever activity from that period is cited later.
It creates immunity for use or publication in India during that interval, so those events cannot be used to refuse, revoke or invalidate the patent.
Disclosures made during the interval can be cited against anything the provisional did not describe, and the claims covering the developed version can fail.
How it works in practice
Talking to customers between the provisional and the complete
Ridham Textiles Pvt Ltd, a Coimbatore MSME, files a provisional specification in March for a yarn tension sensor that reduces breakage on power looms. The provisional describes the sensing arrangement, the mounting and the control logic in reasonable detail. Over the following months the company demonstrates the sensor at three customer mills, publishes a short technical note in an industry newsletter and supplies two units for evaluation. It files the complete specification the next February, within twelve months. During examination a competitor's pre-grant representation cites the newsletter note and the mill demonstrations. Section 33 answers both, because they are use and publication in India after the provisional was filed and they relate to what the provisional described. One claim, however, covers a temperature compensation feature the company invented in September and never mentioned in the provisional. That claim takes the later date, and the newsletter note becomes relevant prior art against it.
Simplified illustration only. Actual legal outcomes depend on the facts.
Key points to remember
- Use or publication in India after the provisional specification cannot be used to refuse, revoke or invalidate the patent.
- The shelter covers what the provisional specification actually describes, not matter added later.
- New matter in the complete specification takes the later date under the priority rules in section 11.
- A comparable protection applies to activity in India after the date of a basic convention application.
- The provisional should be written in full technical detail, because it defines the extent of the protection.
Common mistakes and misunderstandings
- Filing a bare, two-page provisional and assuming everything developed later is protected. Only what the provisional describes gets the earlier date.
- Treating section 33 as worldwide cover. It addresses use and publication in India; foreign offices apply their own rules to the same disclosures.
- Forgetting the twelve-month deadline for the complete specification. If it is not filed in time the application is treated as abandoned and the shelter disappears with it.
Connected provisions
Indian patent law works in two layers. The Act carries the substance and the Rules carry the machinery. Because the layers are amended by different processes and at different times, they are presented in separate blocks instead of being merged into one description.
Forms, deadlines and fees
Forms used under the Patents Rules are prescribed in the Second Schedule. They are revised when the Rules change, so download the current version from the Patent Office website rather than reusing a copy saved earlier.
- The complete specification must follow the provisional specification within twelve months, or the application is treated as abandoned.
- The protection runs from the filing of the provisional specification, so any disclosure made before that date is not covered.
Open the deadline calculator — and have every date confirmed against the current Rules before you rely on it.
Fees are prescribed in the First Schedule to the Patents Rules. Because the Schedule is revised from time to time, and charges different amounts to different categories of applicant and for physical as against electronic filing, this page describes the fee without stating a figure. How Indian patent fees work.
Related judgments
Case summaries are published only after a qualified reviewer has checked the judgment, the citation and the way the holding is described. Nothing has cleared that review for this provision yet, so nothing is listed here. We would rather show no case note than one that misstates what a court decided. How case notes are prepared.
Questions people ask about Section 33
Can I safely talk to investors after filing a provisional?
Section 33 means that use or publication in India after the provisional cannot be used later to refuse or invalidate the patent, so far as the invention described in the provisional is concerned. That is real protection in India. It is not, however, a substitute for care. Anything you invent after the provisional is outside the shelter, foreign patent rights can still be lost by the same conversation, and confidential information you disclose is protected by contract rather than by the Patents Act. Non-disclosure agreements remain worth using.
What happens if my complete specification is broader than the provisional?
The claims are examined against different dates. Claims fairly based on matter disclosed in the provisional keep the provisional date. Claims covering matter first disclosed in the complete specification take the date of the complete specification under section 11. That means any use or publication that occurred in between can be cited against the broader claims. In practice this is the single most common way applicants lose the benefit of an early filing, and it is why the provisional should describe every embodiment you can already articulate.
Does section 33 help with a PCT or convention filing?
The section addresses activity in India, including activity after the date of a basic application filed in a convention country. It does not control how a foreign office treats the same disclosure, and it does not extend any foreign deadline. If you intend to seek rights abroad, plan the foreign filings from the priority date and keep disclosures controlled during the priority year. Remember also that section 39 restricts filing abroad before an Indian filing or without the Controller's written permission.
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