Section 10 of the Patents Act, 1970
Contents of specifications
Sets what a specification must contain: a full description, the best method, clear claims, an abstract, and biological material details.
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 is a simplified explanation. Where it differs from the official text of the provision, or from an applicable Gazette notification, the official text and the notification prevail.
What this section says, in plain language
Section 10 is the drafting rulebook. It tells you what has to be inside a specification, and because a patent is a bargain in which the public gets a full disclosure in exchange for a time-limited monopoly, the requirements here are the public's side of that bargain. A specification that does not meet them can be objected to during examination and attacked after grant.
The description must fully and particularly describe the invention, its operation or use, and the method by which it is to be performed. This is the sufficiency requirement, and the working test is whether a person skilled in the art could perform the invention from the specification without having to invent anything themselves. On top of sufficiency, the specification must disclose the best method of performing the invention known to the applicant and for which the applicant is entitled to claim protection. India takes best method seriously, and holding back the preferred embodiment is a real risk to validity.
The specification must end with a claim or claims defining the scope of the invention for which protection is claimed. Claims must be clear and succinct and fairly based on the matter disclosed in the specification. The claims, not the description, define the monopoly, so an infringement question is answered by reading the claims first. A complete specification must also be accompanied by an abstract giving technical information about the invention, and the Controller may amend an abstract for better information to the public.
Drawings are dealt with practically. The Controller may require drawings where they are needed to understand the invention, and drawings furnished are treated as part of the specification. A model or sample may also be required, but does not form part of the specification.
Biological material has its own rules. Where the invention uses biological material that cannot be described adequately in words and is not available to the public, the material must be deposited with an international depositary authority under the Budapest Treaty, not later than the date of filing. The specification must give the available characteristics of the material, the depositary's name and address and the accession number, and must disclose the source and geographical origin. Failure to disclose or wrongly mentioning the source is separately a ground of opposition and revocation.
Section 10 also carries the unity requirement in a different form from Section 7. Claims may relate to a single invention, or to a group of inventions linked so as to form a single inventive concept. That flexibility lets a product, the process for making it and its specific use sit in one specification when they genuinely share one inventive idea.
Why this section matters
Anyone drafting or reviewing a patent specification, including inventors preparing first drafts and in-house teams checking outside drafts.
During drafting, at every examination round where sufficiency or clarity is objected to, and in any post-grant challenge.
The statutory content requirements for a specification, including sufficiency, best method, clear claims, abstract and biological material disclosure.
Objections during examination, and after grant the patent can be revoked for insufficient disclosure, unclear claims or non-disclosure of the source of biological material.
How it works in practice
The best method left in the lab notebook
Sarvin Life Sciences drafts a specification for a fermentation process that produces an enzyme used in leather processing. The description sets out a workable protocol using a common bacterial strain and generic culture conditions. The team, however, has quietly kept out its real advance, a specific strain isolated from a Chennai tannery effluent sample and a two-stage temperature ramp that doubles yield. They reason that competitors should not get the recipe. Two problems follow. First, the strain is not publicly available and cannot be described adequately in words, so it needed to be deposited with a recognised international depositary authority no later than the filing date, with the accession number and the source and geographical origin disclosed. Second, the withheld protocol is the best method known to the applicant, and Section 10 requires it. When a competitor later petitions for revocation, both points are raised. The lesson the team draws is blunt: what you hold back is not protected, and holding it back can cost you what you did claim.
Simplified illustration only. Actual legal outcomes depend on the facts.
Key points to remember
- The description must let a skilled person work the invention without further invention.
- The best method of performing the invention known to the applicant must be disclosed.
- Claims define the scope of protection and must be clear, succinct and fairly based on the description.
- A complete specification must carry an abstract giving technical information about the invention.
- Drawings, when furnished, form part of the specification; a model or sample does not.
- Biological material that cannot be described must be deposited under the Budapest Treaty by the filing date, with source and geographical origin disclosed.
- Claims may cover a group of inventions only if they form a single inventive concept.
Common mistakes and misunderstandings
- Writing a marketing-style description that praises the invention but never explains how to make it work.
- Keeping the preferred embodiment as a trade secret while patenting a weaker version. This puts the best method requirement in issue.
- Drafting broad claims that the description does not support. Claims must be fairly based on what was disclosed.
- Forgetting to disclose the source and geographical origin of biological material, which is a standalone ground of opposition and revocation.
- Assuming an abstract or a drawing can widen the claims. Scope comes from the claims.
Connected provisions
A section of the Act states what the law requires. The detail of complying with it, including forms, periods and office procedure, sits in the Patents Rules, 2003. The Rules are a separate instrument and change far more often, so they are shown alongside rather than folded into the section.
Forms, deadlines and fees
The Second Schedule to the Patents Rules contains the prescribed forms. A form that has been amended will not match an older saved copy, so take a fresh download from the official site before you fill anything in.
- Where biological material must be deposited with an international depositary authority, the deposit must be made not later than the date of filing the patent application in India.
Open the deadline calculator — and have every date confirmed against the current Rules before you rely on it.
The official fee for anything described on this page is set out in the First Schedule to the Patents Rules. It is not the same for every applicant, and it is not the same for online and physical filing, which is why no amount is stated here. How Indian patent fees work.
Related judgments
Vifor (International) Ltd. & Anr. v. MSN Laboratories Pvt. Ltd. & Anr.
FAO(OS)(COMM) 159/2023, 160/2023 and 161/2023 (Delhi High Court, judgment pronounced 7 February 2024)
Question before the courtWhether a claim that defines a product by the process used to make it protects the product itself or only product made by that process.
HeldThe Division Bench held that where a product is genuinely new and inventive but cannot be described adequately by its structure alone, describing it through its method of preparation does not shrink the monopoly down to that method. The claim protects the product, so a rival who makes the same product by a different route may still infringe. The Court disagreed with the view that one test applies when a patent is granted and a different one when infringement is assessed, and stressed that the novelty must lie in the product.
Case notes are written in our own words from the judgment and are published only after legal review. They are not advice and not a prediction about any other matter. All case notes.
Questions people ask about Section 10
What must a complete specification contain in India?
It must fully and particularly describe the invention, its operation or use, and the method by which it is to be performed. It must disclose the best method of performing the invention known to the applicant. It must end with claims defining the scope of protection, and be accompanied by an abstract giving technical information. Drawings are included where needed and form part of the specification. Where biological material is involved and cannot be described adequately, deposit details and the source and geographical origin must be given.
What is the best method requirement in Indian patent law?
Section 10 requires the applicant to disclose the best method of performing the invention that is known to the applicant and for which the applicant is entitled to claim protection. In practice this means you cannot patent a workable but inferior version while keeping the superior version secret. If the best method known at the filing date was deliberately omitted, the patent can be challenged. Indian practice treats this as a genuine validity requirement rather than a formality, which differs from some other jurisdictions.
What does fairly based mean for patent claims?
It means the claims must find real support in the description. A claim is fairly based if the matter it covers is disclosed in the specification, so an applicant cannot describe one narrow embodiment and then claim an entire field. Examiners raise this as a support or scope objection, often together with sufficiency. The cure is either to narrow the claims to what is actually described, or, where the material exists, to point to the parts of the description and examples that support the breadth being claimed.
Do I have to deposit biological material for an Indian patent?
Only where the invention uses biological material that cannot be described adequately in words and is not available to the public. In that case the material must be deposited with an international depositary authority recognised under the Budapest Treaty no later than the date of filing in India. The specification must then give all available characteristics needed to identify the material, the name and address of the depositary institution, the date of deposit and the accession number, and must disclose the source and geographical origin of the material.
Will your specification survive a validity challenge?
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