Form 18 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.
Form 18 is the request for examination. No patent application is examined unless a request is made, and rule 24B of the Patents Rules, 2003 fixes the form and the period. The Patents (Amendment) Rules, 2024 changed that period from forty-eight months to thirty-one months for applications filed after they came into force, and added a saving clause for earlier filings. If you are counting a deadline, our patent examination request team can confirm which period applies to your application.
A request for examination under section 11B is "made in Form 18 within thirty-one months from the date of priority of the application or from the date of filing of the application, whichever is earlier" (rule 24B(1)(i), as amended in 2024). For an application filed before the 2024 Rules commenced, the period is the one that sub-rule specified before that commencement (rule 24B(1)(vi)). If no request is made in time, the application is treated as withdrawn by the applicant (section 11B(4)). The fee is entry 28 of Table I.
The Act: section 11B
Section 11B(1) says that no application for a patent shall be examined unless the applicant or any other interested person makes a request, in the prescribed manner, within the prescribed period. If no request is made within the period specified under sub-section (1) or (3), the application is treated as withdrawn by the applicant (section 11B(4)). The Act gives no number of months; the Rules do. See section 11B: request for examination.
Rule 24B(1): the periods, as amended in 2024
The Patents (Amendment) Rules, 2024 (G.S.R. 211(E), 15 March 2024) substituted "thirty-one months" for "forty-eight months" wherever those words occur in rule 24B(1), and inserted clause (vi). The clauses now read as follows.
| Clause | Request | Period |
|---|---|---|
| (i) | Request for examination under section 11B, in Form 18 | Thirty-one months from the date of priority or from the date of filing, whichever is earlier |
| (ii) | Request under section 11B(3) | Thirty-one months from the date of priority if applicable, or thirty-one months from the date of filing |
| (iii) | Request under section 11B(4) | Thirty-one months from the date of priority or filing, or six months from the date of revocation of the secrecy direction, whichever is later |
| (iv) | Application filed under the Explanation to section 16(3) | Thirty-one months from the date of filing or from the date of priority of the first mentioned application, or six months from the date of filing of the further application, whichever is later |
| (v) | Applications filed before 1 January 2005 | The period under section 11B before the Patents (Amendment) Act, 2005, or the period under the Rules, whichever expires later |
| (vi) | Application filed before the commencement of the Patents (Amendment) Rules, 2024 | The period specified under sub-rule (1) before that commencement |
Clause (vi) does not restate the older period in figures; the consolidated text before the amendment printed forty-eight months. The 2024 Rules came into force on the date of their publication, 15 March 2024 (rule 1(2) of those Rules). The filing date of the application therefore decides which period applies. The rule-wise article is rule 24B.
After the request: what rule 24B prints
- Where the request is filed and the application has been published under section 11A, the Controller refers it to the examiner in the order in which the request is filed (rule 24B(2)(i)). Publication is explained in Form 9.
- The examiner reports ordinarily within one month but not exceeding three months from reference; the Controller disposes of the report ordinarily within one month (rule 24B(2)(ii), (iii)).
- The first statement of objections issues within one month from the date of disposal of the report (rule 24B(3)).
- The time for putting the application in order for grant under section 21 is six months from the date on which the first statement of objections is issued, and may be extended by three months on a request in Form 4 made before the six months expire (rule 24B(5) and (6)).
National phase: rule 20(4)(ii)
For an application corresponding to an international application designating India, rule 20(4)(i) fixes thirty-one months from the priority date before the Patent Office begins processing, and rule 20(4)(ii) says that, notwithstanding clause (i), the Patent Office may, on the express request filed in Form 18 along with the fee specified in the First Schedule, process or examine the application at any time before thirty-one months. See rule 20.
Fee: entry 28 of Table I
Amounts are as per the First Schedule as substituted in 2024, in rupees, in the order e-filing first column / e-filing others / physical first column / physical others. The first column is a natural person, startup, small entity or educational institution.
| Entry | Head | Amount |
|---|---|---|
| 28(i) | Request for examination under section 11B | 4000 / 20000 / 4400 / 22000 |
| 28(ii) | Request for examination under rule 20(4)(ii) | 5600 / 28000 / 6150 / 30800 |
Entry 28(i) cites "rule 24(1)"; the request for examination rule is 24B(1), and the slip survives in the 2024 table. The extension in rule 24B(6) is charged under entry 4(iii), per month: 1000 / 4000 / 1100 / 4400. Check the current Schedule for later changes. See patent fees by applicant category and filing mode. Rule 7(4A) provides that, on withdrawal of an application for which a request for examination has been filed, before issuance of the first statement of objections, the fee may be refunded to the extent prescribed in the First Schedule on a request in Form 29.
Form 18A and rule 24C: expedited examination
A different form, Form 18A, is used for expedited examination. Rule 24C(1) allows an applicant to file a request for expedited examination in Form 18A with the First Schedule fee, only by electronic transmission, within the period prescribed in rule 24B, on one of the grounds listed in clauses (a) to (j), which include that the applicant is a startup, that the applicant is a small entity, or that India was the competent International Searching Authority or elected International Preliminary Examining Authority. Rule 24C(2) lets a request under rule 24B be converted to one for expedited examination. The fees are entries 29 and 30, which are marked "Not allowed" for physical filing. See rule 24C and our guide on expedited examination for startups, MSMEs and female applicants; grounds should be taken from the rule itself.
Example
Vega Materials Pvt Ltd files on 20 April 2024 with no earlier priority: Form 18 is due within thirty-one months from that date, or section 11B(4) treats the application as withdrawn. A sister company that filed on 10 January 2024 falls under clause (vi).
Common mistakes
- Applying the thirty-one months to an application filed before 15 March 2024 without reading clause (vi).
- Counting from the filing date when an earlier priority date exists.
- Using Form 18 where Form 18A is needed for expedited examination, or the reverse.
Need help with Form 18?
A missed request ends the application. Our patent examination request service diarises the period from the priority or filing date and files Form 18, or Form 18A where a ground applies.
Key takeaways
- Form 18 is the request for examination under section 11B (rule 24B(1)(i)).
- The period is thirty-one months from priority or filing, whichever is earlier; clause (vi) keeps the earlier period for older filings.
- Failure to request means the application is treated as withdrawn (section 11B(4)).
Read next
- Form 9: request for publication
- Form 3: statement and undertaking on foreign applications
- Form 28: status declaration and expedited examination
- Patent examination process: request, first examination report and hearing
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.