Rules 121 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.
Rules 121 to 125 sit at the start of the Miscellaneous chapter. They give three months to file convention-application documents, say where all communications go, and set out how a clerical error in a patent document is corrected, advertised, opposed and notified.
Copies of the specification or corresponding documents called for under section 138(1) must be filed within three months from the date of the Controller's communication (rule 121). All communications go to the Controller at the appropriate office (rule 121A). A request to correct a clerical error must carry a copy of the document with the corrections clearly highlighted and the First Schedule fee (rule 122). If the Controller requires advertisement, the request is published and served on interested persons (rule 123). Any interested person can oppose in Form 14, in duplicate, within three months of the advertisement (rule 124), and the Controller notifies the corrections made (rule 125).
The Act behind these rules
Rule 121 serves section 138(1); see Sections 138-139: supplementary provisions for convention applications. For service of documents and evidence of entries, which sit alongside rule 121A, see Sections 147-149. Rules 122 to 125 serve section 78; see Sections 77-78: the Controller's powers of a civil court and correction of clerical errors.
If you have found an error in a patent document and want to understand the route, our legal consultation team can look at the document with you.
Rule 121: documents for convention applications
The period within which copies of the specification or corresponding documents are to be filed by the applicant under sub-section (1) of section 138 is three months from the date of communication by the Controller. The clock starts on the Controller's communication, not on the date of filing or the date of the application. The rule does not say what happens if the period is missed; the general power to extend time is in rule 138 as substituted in 2024, which our article on Rule 138 explains.
Rule 121A: address of communications
All communications in relation to any proceeding under the Act or the Rules shall be addressed to the Controller at the appropriate office. The meaning of "appropriate office" is dealt with in the rules on the Patent Office's jurisdiction; see our article on Rules 3-4.
Rule 122: request for correction
A request for the correction of a clerical error in any document referred to in section 78 "shall be accompanied by a copy of the document highlighting the corrections clearly along with the fees payable therefor as specified in the First Schedule".
So a request has two attachments: a marked copy and the fee. As per the First Schedule as substituted in 2024, Table I, entry 39 (request for correction of clerical error under section 78(2)):
| Mode | Natural person or startup or small entity or educational institution | Others |
|---|---|---|
| E-filing | Rs 800 | Rs 4000 |
| Physical filing | Rs 880 | Rs 4400 |
Both modes are allowed. No form number is shown against entry 39 (the Form column reads "-"), and the Second Schedule list of forms has no form for this request.
Rule 123: advertising the proposed correction
"Where the Controller requires a notice of the nature of the proposed correction to be advertised", two things follow:
- the request and the nature of the proposed correction shall be published; and
- the person making the request shall also serve copies of the request and of the document showing the proposed corrections on those persons who, in the Controller's opinion, may be interested.
The rule leaves it to the Controller to decide whether an advertisement is needed at all, and to decide who may be "interested". It does not say where the advertisement is published or who bears the cost of publication.
Rule 124: opposing the correction
Sub-rule (1): who, when and how
Any person interested may "at any time, within three months from the date of the advertisement of the request for correction" give notice of opposition to the Controller in Form 14, in duplicate. The phrase "at any time" is followed by a three-month limit, so the limit governs.
Sub-rule (2): the statement
The notice must be accompanied by a statement in duplicate setting out the nature of the opponent's interest, the facts on which he relies and the relief which he seeks.
Sub-rule (3): copy to the requester
A copy of the notice and the statement is sent by the Controller to the person making the request.
Sub-rule (4): procedure of opposition applies
The procedure specified in rules 58 to 63 relating to the reply statement, leaving evidence, hearing and costs shall, so far as may be, apply to the hearing of the opposition under section 78 as they apply to an opposition proceeding. Our articles on Rules 57-58 and Rules 59-61 explain those rules.
The opposition fee
As per the First Schedule as substituted in 2024, Table I, entry 20 covers a notice of opposition to an application under sections 57(4), 61(1) and 87(2), to surrender a patent under section 63(3), or to a request under section 78(5), with Form 14 shown against it:
| Mode | Natural person or startup or small entity or educational institution | Others |
|---|---|---|
| E-filing | Rs 2400 | Rs 12000 |
| Physical filing | Rs 2650 | Rs 13200 |
Both modes are allowed.
Rule 125: notification of corrections
The Controller shall notify the person making the request, and the opponent if any, of the corrections made in the relevant document. The rule does not say how or within what time.
Steps from request to notification
| Step | Rule | Timing |
|---|---|---|
| Request with marked copy and fee | 122 | No period stated |
| Advertisement, if the Controller requires | 123 | Controller's requirement |
| Opposition in Form 14, in duplicate, with statement | 124(1), (2) | Within three months from the advertisement |
| Copy of notice and statement to requester | 124(3) | By the Controller |
| Reply, evidence, hearing, costs | 124(4) with rules 58 to 63 | As in an opposition proceeding |
| Notification of corrections | 125 | No period stated |
What changed in 2024
The sources show no change to the text of rules 121 to 125. The fee entries 39 and 20 are taken from the table substituted by the Patents (Amendment) Rules, 2024.
Practical example
Neelam Instruments Pvt Ltd notices that the patent number on its granted patent document is mistyped. It files a request for correction of a clerical error under section 78, attaching a copy of the document with the corrected number highlighted, and pays the entry 39 fee. Assuming the company is not a startup, small entity or educational institution, the "Others" column applies: Rs 4000 for e-filing. The Controller requires the request to be advertised; Neelam Instruments publishes it and serves a competitor, Orbit Gauges, which the Controller thinks may be interested. Orbit Gauges files Form 14 in duplicate within three months with a statement of its interest. The hearing then follows the procedure of rules 58 to 63. If the correction is made, the Controller notifies both parties.
Need help with a correction or an opposition?
A small error on a granted document can matter when the patent is later relied upon, and an opposition has a short window. Our legal consultation service can help you prepare the marked copy, handle the advertisement and respond to Form 14.
Key takeaways
- Rule 121: three months from the Controller's communication to file documents under section 138(1).
- Rule 121A: communications go to the Controller at the appropriate office.
- Rule 122: a correction request carries a highlighted copy and the fee (entry 39, as substituted in 2024).
- Rule 123: the Controller may require advertisement and service on interested persons.
- Rule 124: opposition in Form 14, in duplicate, within three months from the advertisement, with a statement; rules 58 to 63 apply.
- Rule 125: the Controller notifies the requester and the opponent of the corrections made.
- The text is the Rules as amended up to the Patents (Second Amendment) Rules, 2024; later amendments should be checked.
Read next
- Rules 118–120: alteration, refusal to recognise and publication of patent agents
- Rules 126–127: form of affidavits and exhibits
- Rules 57–58: written statement of opposition and reply statement
- Sections 77–78 of the Patents Act, 1970
Disclaimer: Based on the Patents Rules, 2003 as consolidated up to 21 September 2021 and as amended by the Patents (Amendment) Rules, 2024 and the Patents (Second Amendment) Rules, 2024, as consulted on 2 October 2026. Later amendment rules, forms and fees should be checked in their current form. This article is general information, not legal advice; check the official text before acting.