Sections 50 explained: this guide covers what it means, who it applies to, the step-by-step process, documents required, fees, due dates and penalties in India — so you can stay compliant with confidence and avoid costly mistakes.
Sections 50 and 51 deal with a patent held by two or more persons: who owns what, who may license or assign, and how the Controller can step in when co-owners cannot agree. Section 52 deals with a different problem: a patent obtained from the true and first inventor, which the court may order to be granted to him in place of the wrongful patentee. If you share a patent or want to unwind one, our patent assignment team can help with the documents.
Co-owners hold equal undivided shares unless they agree otherwise (s.50(1)). Each may use the invention for his own benefit without accounting to the others, but no licence may be granted and no share assigned without the consent of the others (s.50(2) and (3)). The Controller can give directions on sale, lease and licences, and if a co-owner fails to sign within fourteen days of a written request, the Controller can authorise someone to sign for him (s.51). Under s.52 the court can order a new patent for the true inventor; no suit lies for infringement before the date of that grant.
Section 50: rights of co-owners
The printed text is current. The only amendment is in sub-section (2): the words "the rights conferred by section 48" were substituted by the Patents (Amendment) Act, 2002 (from 20 May 2003) for the older words "make, use, exercise and sell the patented invention". Our article on section 48 sets out those rights.
Sub-section (1): equal shares
"Where a patent is granted to two or more persons, each of those persons shall, unless an agreement to the contrary is in force, be entitled to an equal undivided share in the patent." If the grant is to three people and they have no agreement, each holds one-third undivided. An agreement can change the split.
Sub-section (2): own benefit, no accounting
Where two or more persons are registered as grantee or proprietor, each is entitled, "by himself or his agents", to the rights conferred by section 48 "for his own benefit without accounting to the other person or persons", unless an agreement says otherwise. The sub-section is "subject to" section 50 and section 51. So a co-owner who works the patent and earns profit need not share it, unless the co-owners agreed otherwise.
Sub-section (3): licence and assignment need consent
"A licence under the patent shall not be granted and a share in the patent shall not be assigned by one of such persons except with the consent of the other person or persons." This is also subject to any agreement for the time being in force. A co-owner can use the patent alone, but cannot license it to a third party or sell his share without the others.
Sub-sections (4) to (6)
| Sub-section | Rule |
|---|---|
| (4) | If a patented article is sold by one registered co-owner, the buyer and anyone claiming through him may deal with the article as if sold by a sole patentee |
| (5) | Subject to section 50, the rules of law on ownership and devolution of movable property apply to patents; sub-sections (1) and (2) do not affect the mutual rights or obligations of trustees or of the legal representatives of a deceased person |
| (6) | The rights of assignees of a partial interest created before the commencement of the Act are not affected |
Section 51: Controller's directions to co-owners
Sub-section (1): directions on application
Where two or more persons are registered as grantee or proprietor, the Controller "may, upon application made to him in the prescribed manner by any of those persons, give such directions in accordance with the application as to the sale or lease of the patent or any interest therein, the grant of licences under the patent, or the exercise of any right under section 50 in relation thereto, as he thinks fit." The manner of application is prescribed by the Patents Rules, 2003; the text gives no form or fee.
Sub-section (2): the fourteen-day default
If a registered co-owner "fails to execute any instrument or to do any other thing required for the carrying out of any direction given under this section within fourteen days after being requested in writing so to do by any of the other persons so registered", the Controller may, on application in the prescribed manner by that other person, give directions "empowering any person to execute that instrument or to do that thing in the name and on behalf of the person in default."
Sub-section (3): hearing first
Before directing, the Controller must give an opportunity to be heard: under sub-section (1), to the other registered co-owners; under sub-section (2), to the person in default.
Sub-section (4): limits
No direction may affect the mutual rights or obligations of trustees or of the legal representatives of a deceased person, or their rights or obligations as such, or "be inconsistent with the terms of any agreement between persons registered as grantee or proprietor of the patent". The Controller cannot override a co-ownership agreement.
Section 52: patent obtained in fraud of the true inventor
The words "Where the patent has been revoked under section 64" were substituted by the 2005 Act (from 1 January 2005), and the reference to the Appellate Board was dropped by the Tribunals Reforms Act, 2021 (from 4 April 2021), so the text speaks of "the court". Revocation itself is covered in our article on section 64.
Sub-section (1): the court may permit a grant to the petitioner
Two situations trigger it:
- the patent is revoked "on the ground that the patent was obtained wrongfully and in contravention of the rights of the petitioner or any person under or through whom he claims"; or
- in a revocation petition, the court, instead of revoking, directs the complete specification to be amended by excluding a claim or claims "in consequence of a finding that the invention covered by such claim or claims had been obtained from the petitioner".
In either case the court "may, by order passed in the same proceeding, permit the grant to the petitioner of the whole or such part of the invention" that it finds was wrongfully obtained by the patentee, in place of the patent revoked or the claim excluded.
Sub-section (2): what the Controller grants
On the petitioner's request made in the prescribed manner:
- (i) if the whole is permitted: "a new patent bearing the same date and number as the patent revoked";
- (ii) if only part is permitted: "a new patent for such part bearing the same date as the patent revoked and numbered in such manner as may be prescribed".
The proviso lets the Controller, as a condition of the grant, require a new and complete specification describing and claiming that part.
Sub-section (3): no suit for past infringement
"No suit shall be brought for any infringement of a patent granted under this section committed before the actual date on which such patent was granted." The new patent bears the old date but gives no right to sue for earlier infringement.
Illustrations (invented)
Co-owners. Aarav and Meenal hold a joint patent on a solar dryer, with no agreement. Each owns half. Aarav manufactures dryers and keeps the profit; section 50(2) does not make him account to Meenal. When Aarav wants to license the design to Sundar Agro Pvt. Ltd., Meenal's consent is needed under section 50(3).
Deadlock. Meenal refuses to sign the licence. Aarav applies to the Controller under section 51(1). The Controller hears Meenal, then may direct the grant of the licence. If Meenal still does not sign within fourteen days of Aarav's written request, Aarav applies under section 51(2) and the Controller may empower a person to sign for her.
Fraud. Rohan shows his drawings of a water-saving valve to a consultant, who files for a patent in his own name. In a revocation petition, the court finds the invention was obtained from Rohan. It revokes the patent and permits a grant to Rohan. The Controller grants Rohan a new patent with the same date and number. Rohan cannot sue for infringement committed before the date of the new grant.
What the sections do not say
- No fee, form or procedure for the Controller's application beyond "prescribed manner".
- No limit on the kinds of direction, beyond the topics in section 51(1) and the limits in section 51(4).
- Section 50 speaks of persons "registered" as grantee or proprietor in sub-sections (2) and (3); registration of interests is in our later article on the register of patents.
- No time limit for the petitioner's request under section 52(2).
Need help with a jointly owned patent?
Co-ownership without a written agreement leaves both partners tied by consent rules. Our patent assignment team can prepare a co-ownership or assignment agreement that settles shares, licensing and exit before a dispute arises.
Key takeaways
- Co-owners hold equal undivided shares unless an agreement says otherwise.
- Each may use the patent for his own benefit without accounting, but licences and assignments of a share need the others' consent.
- The Controller may direct sale, lease or licences on application and can authorise a signatory after fourteen days of default, after hearing the other side.
- Section 52 lets the court permit a new patent to the true inventor; there is no suit for infringement before that grant.
Read next
- Section 53: term of patent
- Section 49: patent rights not infringed on foreign vessels
- Patent assignment vs licence: key differences
- Patent licence agreement: draft template
Disclaimer: Based on the Patents Act, 1970 as amended up to the Jan Vishwas (Amendment of Provisions) Act, 2023, as consulted on 1 October 2026. Forms, fees and time limits under the Patents Rules, 2003 change from time to time and are not covered here. This article is general information, not legal advice; check the official text before acting.