When you file a PCT application, one of the most consequential decisions you make is choosing an International Searching Authority (ISA). For applicants who intend to enter the Indian national phase, choosing the Indian Patent Office (IPO) as ISA is not merely an administrative preference: it determines whether you can access expedited examination in India, and how quickly a granted patent can be in your hands.
The Indian Patent Office has been designated as an ISA and International Preliminary Examining Authority (IPEA) under the Patent Cooperation Treaty (PCT) since 15 October 2013. Under Rule 24C of the Patents Rules, 2003 (as amended), applicants who have designated India as ISA or elected India as IPEA in their corresponding PCT application become eligible to file a Request for Expedited Examination (Form 18A) when they enter the Indian national phase. For foreign applicants and large entities, this is the primary, and often the only, route to expedited examination in India.
This guide explains exactly who can choose India as ISA, what the designation involves, what it costs compared with other major ISAs, and how to make the designation correctly at the PCT filing stage. It also covers the common mistake that costs applicants their Form 18A eligibility before they ever reach Indian prosecution.
1. What the ISA and IPEA Designations Mean
Every PCT application undergoes an international search conducted by an ISA (one of a limited number of national or regional patent offices authorised by the PCT Assembly to carry out that function). The ISA establishes the International Search Report (ISR) and a Written Opinion on novelty, inventive step, and industrial applicability. These are issued before national phase entry and are available to all designated offices.
Separately, an applicant may request international preliminary examination under PCT Chapter II by filing a Demand with an International Preliminary Examining Authority (IPEA). The IPEA produces an International Preliminary Report on Patentability (IPRP Chapter II). Filing a Demand is optional; if no Demand is filed, the Written Opinion of the ISA is automatically transmitted to designated offices as an IPRP Chapter I.
The ISA designation is made at the time of filing the PCT application and cannot be changed after filing. The IPEA is selected when filing the Demand under Chapter II, which must be filed within three months from the date of transmittal of the ISR and Written Opinion, or within 22 months from the earliest priority date, whichever deadline is later (PCT Rule 54bis.1).
India’s competence as ISA and IPEA is confirmed in the PCT Applicant’s Guide (India), Annex D and Annex E, published by WIPO at pctlegal.wipo.int. The current version (effective 1 September 2025) governs the fees and eligibility rules described in this post.
2. Who Can Choose India as ISA
The ISA that an applicant can choose depends on the Receiving Office (RO) where the PCT application is filed. This is a firm constraint set by the PCT system: not every ISA is available to every applicant.
2.1 Applicants filing at RO/IN (Indian Patent Office as Receiving Office)
Nationals and residents of India who file at RO/IN may choose India (IPO) as ISA. They may also choose the Austrian Patent Office (AT), Australian Patent Office (AU), China National Intellectual Property Administration (CN), European Patent Office (EP), Japan Patent Office (JP), Swedish Intellectual Property Office (SE), or the United States Patent and Trademark Office (US).
2.2 Foreign applicants filing at RO/IB (International Bureau of WIPO as Receiving Office)
The International Bureau of WIPO (RO/IB) accepts filings from nationals and residents of any PCT Contracting State. When filing at RO/IB, an applicant’s available ISAs depend on the ISAs that have agreed to serve applicants from that RO. India (IPO) is available as an ISA for applicants filing at RO/IB from certain Receiving Offices, including RO/IN. Foreign applicants from major jurisdictions (US, Europe, Japan, Korea, China) who file at their home ROs typically cannot select India as ISA from those ROs. For the complete list of Receiving Offices for which India (IPO) is a competent ISA or IPEA, verify Annex C(IN) and Annex E(IN) of the WIPO PCT Applicant’s Guide at pctlegal.wipo.int.
| KEY POINT FOR FOREIGN APPLICANTS If you are a US, European, Japanese, Korean, or Chinese applicant and you want to choose India as ISA, you must file your PCT application at RO/IB (the International Bureau of WIPO). Filing at your national RO, such as the USPTO as RO/US or the EPO as RO/EP, will not give you access to India as ISA. Verify your available ISAs with your patent agent before filing. |
3. The Strategic Case for India as ISA
3.1 Form 18A eligibility: the primary benefit
Under Rule 24C of the Patents Rules, 2003 (as amended), expedited examination in India requires the applicant to fall within one of several prescribed categories. For foreign applicants and large entities, the relevant category is having designated India as ISA or elected India as IPEA in the corresponding PCT application.
Under the standard examination route (Form 18), a PCT application filed on or after 15 March 2024 enters a general examination queue after the RFE is filed. Under Form 18A (expedited), the application enters a separate, priority queue. In practice, applicants filing Form 18A have reported receiving a First Examination Report within a significantly shorter period compared with the standard route, subject to IPO workload at the time of filing. For a full overview of how patent examination works in India, including procedures, forms, fees, and typical timelines, see our guide to patent examination procedure in India.
The ISA/IPEA designation is verified by the IPO against the WIPO international application record when Form 18A is filed. Applicants should confirm that the designation is correctly recorded in the international filing documents before relying on it at national phase entry.
This eligibility link is not retrospective. If a foreign applicant chooses EPO or USPTO as ISA and later wishes they had chosen India, there is no mechanism to change the ISA after filing. The Form 18A route will not be available to that applicant in India, regardless of the application’s commercial urgency.
3.2 Search fee advantage
The IPO-ISA search fee is substantially lower than the fees charged by the EPO, USPTO, and JPO. The following table compares ISA search fees effective from 1 September 2025 (WIPO PCT Applicant’s Guide, Annex D). All non-INR equivalents are approximate based on the INR amounts stated in the official schedule.
| ISA | Large Entity (USD equiv.) | Startup / Natural Person (USD equiv.) | Language |
| India (IPO) | ~119 USD (10,000 INR)* | ~30 USD (2,500 INR)* | English, Hindi |
| EPO | EUR 1,845 (~USD 2,054) | EUR 1,845 (no reduction for entity type) | Many EU languages |
| USPTO | ~2,300 USD | ~920 USD (60% reduction, micro entity) | English |
| JPO | ~1,400 USD | ~1,400 USD (no reduction) | Japanese / English |
* Source: WIPO PCT Applicant’s Guide, Annex D(IN), effective 1 September 2025. INR amounts are exact; USD equivalents are approximate. Natural person, startup, small entity, and educational institution rates apply subject to correct classification and filing of Form 28 where required. Verify the current schedule at pctlegal.wipo.int before filing, as fees are updated periodically.
3.3 Language
The IPO-ISA conducts searches in English. For applicants filing in English at RO/IN, there is no translation requirement for the international search. Filing at RO/IN with India as ISA in English is the most straightforward procedural route.
Applications filed in Hindi at RO/IN must be accompanied by an English translation for ISA purposes under PCT Rule 12.3. For foreign applicants filing at RO/IB, English is the accepted language for international applications intended for the IPO-ISA.
3.4 Prior art coverage considerations
Applicants should be aware that the ISR issued by the IPO covers prior art from major patent databases accessible to the IPO, including WIPO PatentScope, the Indian patent database, and international patent literature. In practice, applicants with technology areas where significant prior art exists in Asian-language databases, particularly Japanese or Korean, may wish to consider whether a supplementary international search would add value. PCT Rule 45bis.1 allows filing a request for supplementary search with a second ISA if the primary ISR leaves prior art gaps.
The ISR from the IPO-ISA is a non-binding opinion and does not predetermine the outcome of examination in any designated office, including the IPO itself. A favourable Written Opinion from the IPO-ISA may, however, provide a useful basis for prosecution arguments at the national phase.
4. Key Deadlines: From PCT Filing to Form 18A
The table below maps the critical procedural milestones from PCT filing through to Form 18A at Indian national phase entry. All deadlines marked in the right column are hard deadlines; no general grace period applies in India for national phase entry or for the RFE.
| Milestone | Deadline | Statutory Basis |
| PCT international filing at RO/IN | Any time (ISA designation at this stage) | PCT Rule 4.1; PCT Rule 19 |
| ISR and Written Opinion issued by IPO-ISA | By 16 months from priority date | PCT Rule 42.1 |
| Application published by WIPO | 18 months from earliest priority date | PCT Article 21 |
| National phase entry in India | 31 months from earliest priority date | PR Rule 20(4); PCT Article 22(3) |
| Form 18 / Form 18A (RFE): applications filed on or after 15 March 2024 | 31 months from earliest priority date | PA Sec. 11B; PR Rule 24B(1)(i) (eff. 15 March 2024) |
| Form 18 / Form 18A (RFE): applications filed before 15 March 2024 | 48 months from earliest priority date | PR Rule 24B(1)(vi) (pre-amendment) |
Note: The 31-month RFE deadline under Rule 24B(1)(i) applies to applications filed on or after 15 March 2024 (the effective date of the Patents (Amendment) Rules, 2024). Applications filed before that date continue to be governed by the 48-month RFE deadline under Rule 24B(1)(vi).
5. Form 18A Eligibility at a Glance
Form 18A is available under Rule 24C of the Patents Rules, 2003. Eligibility depends on the applicant’s category. The table below summarises who qualifies and whether an ISA/IPEA designation is required.
| Applicant Category | ISA/IPEA Requirement for Form 18A | Notes |
| Startup (DPIIT-recognised, India-incorporated) | Not required; startup status alone qualifies | Recognition must be valid on date of filing Form 18A |
| Small entity / natural person / female applicant | Not required; category alone qualifies | Prescribed declaration required |
| Foreign applicant or large entity | India (IPO) must have been designated as ISA or elected as IPEA in the corresponding international application | This is the only Form 18A route available to foreign large entities |
| Government-supported institution | Not required; category qualifies | Documentary evidence of government support required |
Source: Rule 24C, Patents Rules, 2003 (as amended). Fee amounts per Annex IN.I, WIPO PCT Applicant’s Guide (India), effective 1 September 2025. Form 18A must be filed electronically. The fee for large entities / others is INR 60,000; for startups, small entities, natural persons, and educational institutions it is INR 8,000, subject to entity classification at date of filing. For a detailed guide on the Form 18A procedure, see our detailed guide on expedited patent examination in India under Rule 24C.
6. How to Designate India as ISA: Step-by-Step
The ISA designation is made in the PCT Request Form at the time of international filing. The following steps apply to applicants filing at RO/IN or RO/IB.
| Step | Action |
| 1 | Confirm eligibility: the application must be filed at RO/IN (the Indian Patent Office as Receiving Office) or, for foreign applicants, at RO/IB (International Bureau of WIPO). India as ISA is available when filing at RO/IN or RO/IB provided the applicant meets nationality or residence requirements or files via RO/IB. |
| 2 | In the PCT Request Form (Form PCT/RO/101), locate Box No. VIII (Request to Search by a Particular International Searching Authority). Enter: International Searching Authority: Indian Patent Office (IN). |
| 3 | Pay the ISA search fee to the RO at the time of filing. If filing at RO/IN, payment is in INR via the IPO’s e-filing portal (ipronline.ipindia.gov.in). If filing at RO/IB, check accepted currencies with IB. |
| 4 | File the PCT application in English (or Hindi if filing at RO/IN, with English translation). The IPO-ISA conducts searches in English; applications in other languages require an English translation for search purposes under PCT Rule 12.3. |
| 5 | Retain the ISA/IPEA designation record. When entering the Indian national phase at 31 months, this designation is the basis for Form 18A eligibility. The IPO cross-references the international application number against ISA/IPEA records. |
| PRACTITIONER NOTE In practice, applicants commonly include the ISA designation and entity classification in their filing instructions to their patent agent at the outset of a PCT filing engagement, not at national phase entry. By the time the national phase deadline approaches, the ISA choice is fixed and cannot be changed. Agents acting for foreign applicants with Indian national phase intentions should flag the ISA choice explicitly in their filing instructions. |
7. The IPEA Route: Chapter II Demand With India as IPEA
If the ISA selected at PCT filing stage was not India, there is one remaining option to access the Form 18A eligibility route: filing a Chapter II Demand with India as IPEA. The Demand must be filed within three months from the date of transmittal of the ISR and Written Opinion, or within 22 months from the earliest priority date, whichever is later (PCT Rule 54bis.1). An additional fee (the IPEA preliminary examination fee) is payable to the IPO.
The current IPEA fees payable to the Indian Patent Office (effective 1 September 2025, per WIPO PCT Applicant’s Guide Annex E) are:
- INR 12,000 : large entity/other, where the ISR was prepared by an authority other than IPO
- INR 10,000 : large entity/other, where the ISR was prepared by IPO (reduced rate)
- INR 3,000 : startup, natural person, small entity, educational institution (ISR by other authority)
- INR 2,500 : startup, natural person, small entity, educational institution (ISR by IPO)
Additionally, the WIPO handling fee (PCT Rule 57.1) is payable at CHF 200 (approximately USD 251 at 1 January 2026 exchange rates), subject to 90% reduction for qualifying applicants from States classified as least developed countries by the United Nations. The CHF amount is fixed; the USD equivalent varies with exchange rates.
Electing India as IPEA and filing the Demand confers Form 18A eligibility on the same basis as ISA designation. However, this route involves additional cost and the Demand must be filed within the Chapter II deadline. It is not a substitute for selecting India as ISA at the outset; rather, it is a remedy for applicants who initially chose a different ISA and now wish to preserve the expedited examination option for India.
8. Common Pitfalls and How to Avoid Them
| Pitfall | What Goes Wrong | How to Avoid It |
| Choosing EPO or USPTO as ISA on a PCT application that will enter India | The applicant loses Form 18A eligibility at national phase entry in India. The application joins the standard examination queue regardless of how commercially urgent the Indian grant is. | If India is a priority market, designate India as ISA at the PCT filing stage. This decision cannot be changed after filing. |
| Assuming Form 18A eligibility transfers from the international phase without verification | Applicants sometimes believe that filing a Chapter II demand with any IPEA qualifies them for Form 18A. Only India as ISA or IPEA qualifies. | Verify at national phase entry that the original PCT application record shows IN as ISA or IPEA before filing Form 18A. |
| Filing Form 18A without confirming publication status | Form 18A cannot be processed until the application is published. Applicants who file Form 18A before publication face procedural delay. | If the application has not yet been published under Section 11A, file a request for early publication (Form 9) alongside Form 18A. |
| Missing the 31-month RFE deadline for post-March 2024 applications | Under Rule 24B(1)(i) (effective 15 March 2024), Form 18 or Form 18A must be filed within 31 months. Missing this deadline renders the application liable to be treated as withdrawn. | Plan to file both the national phase application and the RFE (Form 18 or Form 18A) simultaneously at or before the 31-month deadline. |
| Overlooking entity classification at Form 18A filing | Filing Form 18A at the large entity rate when the applicant qualifies as a startup or small entity results in overpayment. The reverse: claiming a concessional rate without supporting declaration triggers a formal objection. | File Form 28 (small entity declaration) or confirm DPIIT startup recognition before filing Form 18A. Ensure entity classification in Form 18A matches all other filed forms. |
Conclusion
For applicants with India as a meaningful market in their PCT portfolio, designating the Indian Patent Office as ISA is a filing-stage decision with downstream consequences in prosecution. It unlocks Form 18A expedited examination eligibility for categories of applicants, particularly foreign large entities, who would otherwise have no route to priority queue treatment at the IPO. It also offers a materially lower search fee compared with the major Western and East Asian ISAs.
The decision must be made at the PCT filing stage. It cannot be corrected or changed after the international application is filed. Applicants who intend to enter the Indian national phase and want the option of expedited examination should discuss ISA selection with their patent agent as part of the initial PCT filing strategy, before the application is submitted.
If the ISA choice has already been made and India was not designated, the Chapter II Demand route via India as IPEA remains available within the applicable deadline. This preserves Form 18A eligibility at the cost of additional fees and procedural steps. The right course of action depends on the application’s commercial timeline and the content of the Written Opinion issued by the original ISA.
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Legal Disclaimer
This post is for informational purposes only and does not constitute legal advice. For advice specific to your situation, consult a registered patent or patent attorney.
Frequently Asked Questions
Q1. Can a foreign applicant (not a resident or national of India) choose India as ISA?
Yes, provided the PCT application is filed at the International Bureau of WIPO (RO/IB). India is available as an ISA for applicants filing at RO/IB. Foreign applicants who file at their home country’s Receiving Office, such as the USPTO acting as RO/US or the EPO acting as RO/EP, typically cannot access India as ISA from those offices. Confirm available ISAs with your patent agent before filing.
Q2. If I choose India as ISA but enter the national phase in multiple countries, does the ISA choice affect prosecution in those other countries?
The ISR and Written Opinion issued by the IPO-ISA are transmitted to all designated offices as part of the PCT file. Each national or regional office will independently assess patentability against its own law, but the ISR is publicly available and forms part of the file history. The weight given to the IPO-ISA’s Written Opinion varies by office. Some offices treat a positive Written Opinion favourably; others conduct independent examination regardless. The ISA choice does not restrict prosecution strategy in any designated office.
Q3. I already filed my PCT application with EPO as ISA. Can I still access Form 18A in India?
Yes, through the Chapter II Demand route. If you file a Demand for international preliminary examination and elect India (IPO) as IPEA within the applicable deadline (3 months from transmittal of the ISR and Written Opinion, or 22 months from priority, whichever is later under PCT Rule 54bis.1), you will become eligible for Form 18A at Indian national phase entry. This involves additional fees payable to the IPO as IPEA. If the Chapter II deadline has also passed, the Form 18A route is no longer available for that application.
Q4. Does choosing India as ISA guarantee a faster grant in India?
No. Choosing India as ISA makes you eligible to file Form 18A, which places the application in a priority examination queue. It does not guarantee grant within a fixed timeframe. The overall timeline to grant depends on IPO workload, the number and complexity of objections raised in the First Examination Report (FER), and how promptly the applicant responds to those objections. Expedited examination accelerates queue position; it does not eliminate substantive examination.
Q5. What form is used to request expedited examination, and when must it be filed?
Form 18A is filed electronically on the IPO’s e-filing portal. For PCT applications filed on or after 15 March 2024, Form 18A must be filed within 31 months from the earliest priority date, the same deadline as Form 18 under Rule 24B(1)(i) (effective 15 March 2024). For applications filed before that date, the 48-month deadline continues to apply. The application must also be published (or a request for early publication filed) before Form 18A can be processed.
Q6. Is the India ISA search fee always lower than other ISAs?
As at 1 September 2025, the India ISA search fee is INR 10,000 (approximately USD 119) for large entities and INR 2,500 (approximately USD 30) for startups, natural persons, small entities, and educational institutions. These are among the lowest ISA search fees available under the PCT system. However, ISA fees are updated periodically by each authority and notified to WIPO. Verify the current fee at pctlegal.wipo.int before filing. The fee figures in this post reflect Annex D(IN), effective 1 September 2025.
Q7. Does India as ISA affect the renewal fee structure or national phase fees in India?
No. ISA designation affects only the availability of Form 18A (expedited examination) and the ISA search fee payable at the international stage. National phase filing fees, RFE fees, Form 18 or Form 18A fees, and annual renewal fees are governed by the First Schedule of the Patents Rules, 2003 (as amended), and apply equally regardless of which ISA was chosen. The full fee schedule is available at ipindia.gov.in.
Q8. My PCT application was filed by an Indian subsidiary of a foreign company. Does the subsidiary qualify as a startup for the India ISA search fee reduction?
Entity classification under the PCT and under Indian patent law must be assessed separately. For the India ISA search fee, the categories eligible for the reduced rate include startups as notified by the Government of India under DPIIT startup recognition norms, natural persons, small entities, and educational institutions. An Indian subsidiary incorporated as a private limited company may qualify as a startup if it meets the DPIIT criteria. A registered patent agent can advise on entity classification based on the specific corporate structure.
