There are 9 types of patent applications in India, listed on the Indian Patent Office’s Form 1. Filing under the wrong type can permanently forfeit your priority date, and there is no mechanism to recover it.
Which type applies to you depends on one question: where did you file first? If India is your first filing country, you are on the ordinary route (Part A). If you have an earlier application in another Paris Convention country, you are on the conventional route (Part B). If you filed internationally through WIPO’s PCT system, you enter India through the PCT national phase route (Part C). Each route contains three application types: the primary application, a type for protecting improvements (Patent of Addition), and a type for splitting a multi-invention application (Divisional). The right type follows once you know your route.
This guide covers all 9 types in plain language: what each one does, who it is for, and which deadlines apply. For the full step-by-step filing process, see Patent Filing Procedure and Process in India. To confirm your invention qualifies first, see What Can Be Patented in India.
The 9 Types at a Glance: A 3×3 Map
The structure is straightforward once you see it. Three routes, three types per route, nine in total. The two sub-types in each route (Patent of Addition and Divisional) are variations on the primary application in that route, not separate routes of their own. If you know which row applies to you, the column tells you the exact type you need.
| Primary Route | Patent of Addition (for improvements) | Divisional Application (for splitting inventions) |
| Ordinary Application (India first-filing country) | Patent of Addition for Ordinary | Divisional Ordinary Application |
| Conventional Application (prior Paris Convention filing) | Patent of Addition for Conventional | Divisional Conventional Application |
| PCT National Phase (prior PCT international filing) | Patent of Addition for PCT NP | Divisional PCT National Phase |
Note: Both the conventional route (Part B) and the PCT national phase route (Part C) are used by foreign applicants entering India. The difference is the filing mechanism and the priority window available. Part B covers direct national entry; Part C covers entry through WIPO’s PCT system.
Part A: The Ordinary Route (Types 1–3)
The ordinary route applies when India is your first filing country and you have no earlier foreign application to claim priority from. This section covers the three types of patent application in this route in order of complexity.
| 1. Ordinary Application [Most common for Indian inventors] | |
| Statutory basis | Section 7, Patents Act 1970 |
| Form | Form 1 + Form 2 (specification) |
| Provisional option | Yes. You may file a provisional specification first to lock in your priority date, then follow up with a complete specification within 12 months. |
| Key deadline | If filing provisional first: the complete specification must be filed within 12 months under Section 9(1). Automatic abandonment on day 366. No extension. No revival. Priority date permanently lost. |
| Who uses it | Indian startups, MSMEs, and individual inventors filing for the first time in India with no prior foreign application. |
The ordinary application is the most common type of patent application for Indian inventors. If your invention is fully documented, file a complete specification directly. If you are still refining it, the provisional specification option lets you lock in your priority date now at lower cost and finish the documentation within 12 months.
Provisional vs Complete Specification for an Ordinary Patent Application
Every ordinary application requires a specification, the technical document that describes your invention. Two options are available.
| Provisional Specification | Complete Specification | |
| Purpose | Secures your priority date early while the invention is still being finalised | Formally defines the invention and the scope of protection claimed |
| Claims | Not required | Mandatory — claims define exactly what is protected |
| Deadline | Complete spec must be filed within 12 months | No conversion deadline if filed directly as complete |
| Cost | Lower initial government fee | Higher fee — based on claims count and page length |
| Best for | Invention still being developed or refined | Invention fully documented and ready to protect |
The key rule: once you file a provisional specification, the 12-month clock starts the same day. If the complete specification is not on file within 12 months, the application is automatically abandoned under Section 9(1). No grace period. No revival. The priority date cannot be recovered.
For a complete walkthrough of the filing process, required forms, fees, and common mistakes, see How to File a Provisional Patent Application in India.
| Plain-language tip: |
| Think of the provisional specification as staking your claim on an invention date. The complete specification, filed within 12 months, then formally defines exactly what protection you are asking for. |
| ⚠ Critical deadline: |
| If you file a provisional specification today, set a hard reminder for 11 months from now — not 12. You need time to draft and review the complete specification before the window closes. |
| 2. Patent of Addition for Ordinary Application [For improvements on an existing ordinary patent] | |
| Statutory basis | Section 54, Patents Act 1970 |
| Parent | An existing ordinary patent application (pending) or a granted ordinary patent. |
| Inventive step | Does not need to independently satisfy the full inventive step requirement. Only needs to be a genuine improvement or modification of the main invention. |
| Renewal fees | None. No separate annual renewal fees are payable; a meaningful cost saving across the patent’s life. |
| Expiry | Expires at the same time as the parent patent. It cannot outlive the main patent. |
| Who uses it | Indian startups and MSMEs making iterative improvements to an already-filed or granted invention. |
A patent of addition is best understood with an example. Suppose your main patent protects a new type of water filter. You later develop a better filter membrane. The membrane improvement may not qualify as a standalone patent because it lacks independent inventive step over your own earlier patent. It can, however, be protected as a patent of addition, with no separate renewal fees for the rest of the main patent’s 20-year life.
In practice: Patent of addition filings are common in mechanical engineering, food processing, and consumer products — areas where incremental improvements are routine and the cost of maintaining a separate full patent for each iteration would be prohibitive.
| 3. Divisional Ordinary Application [When your application covers more than one invention] | |
| Statutory basis | Section 16, Patents Act 1970 |
| Parent | An existing ordinary application that contains claims for more than one distinct invention. |
| Key deadline | Must be filed before the parent ordinary application is granted. Once the parent is granted, this window closes permanently. |
| Priority date | Same as the parent application. No new technical matter may be introduced in the divisional. |
| Fees | Each divisional application attracts its own filing and examination fees independently. |
| Who uses it | Applicants whose ordinary application received a unity of invention objection from the Controller, or who want to proactively separate multiple inventions. |
The unity of invention rule (Section 10(5), Patents Act 1970) requires each patent application to cover a single invention. If your application discloses two distinct inventions, the Controller may raise a unity of invention objection in the First Examination Report. The solution is to file a divisional application before the parent is granted, splitting the inventions into separate applications while preserving the same priority date for both.
In practice: Do not wait for an objection. If you know your application covers more than one invention, consider filing the divisional proactively — before examination. This avoids the risk of missing the divisional window if the parent moves faster than expected.
Part B: The Conventional Route (Types 4–6)
The conventional route applies to any applicant, Indian or foreign — who has already filed a patent application in a Paris Convention member country and wants to carry that earlier filing date into India. This is the direct national filing route: you file straight into the Indian Patent Office, claiming priority from your earlier application abroad. Over 170 countries are Paris Convention members, including the US, UK, EU member states, Japan, China, South Korea, and Australia. The full list of member countries is on the WIPO website.
Conventional route vs PCT national phase: Both routes serve applicants who filed abroad first. The difference is the filing mechanism. If you filed a national application in a single convention country and are now entering India directly, use the conventional route — you have a 12-month window from that first filing. If you filed a PCT international application through WIPO designating multiple countries, use the PCT national phase route in Part C instead — that window is 31 months. You cannot use both routes for the same invention filing.
| 4. Conventional Application [For applicants with a prior foreign filing] | |
| Statutory basis | Section 135, Patents Act 1970 |
| What it does | Allows you to claim the priority date of your earlier foreign application in India. Prior art published after your foreign filing date cannot be used against your Indian application. |
| Key deadline | Must be filed in India within 12 months of the date of your first filing in any convention country. The clock starts from the very first filing, regardless of how many countries you file in subsequently. |
| Specification | Complete specification mandatory. A provisional specification cannot be filed for a conventional application. |
| Priority document | A certified copy of the earlier foreign application is required. If the priority country participates in WIPO DAS, the document can be retrieved electronically. |
| Who uses it | Indian or foreign applicants who have filed first in a Paris Convention country and want to extend protection to India within the 12-month priority window. Foreign companies entering India without a PCT filing use this route. |
| In practice: A company that filed a US patent application in January 2025 has until January 2026 to file a conventional application in India and claim the US filing date as its Indian priority date. Missing this window means any prior art published between the US filing and the Indian filing date can be used against the Indian application. |
| 5. Patent of Addition for Conventional Application [For improvements on an existing conventional patent] | |
| Statutory basis | Section 54, Patents Act 1970 |
| Parent | An existing conventional patent application (pending) or a granted conventional patent in India. |
| Inventive step | Does not need to independently satisfy the full inventive step requirement. |
| Renewal fees | None. No separate annual renewal fees payable. |
| Expiry | Expires at the same time as the parent conventional patent. |
| Who uses it | Applicants holding a conventional patent in India who are developing improvements to the patented invention. |
This type of patent application works identically to the Patent of Addition for Ordinary Application. The only difference is that the parent patent entered India through the conventional route. The cost saving on renewal fees and the relaxed inventive step standard apply equally.
| 6. Divisional Conventional Application [When your conventional application covers more than one invention] | |
| Statutory basis | Section 16, Patents Act 1970 |
| Parent | An existing conventional application in India containing claims for more than one distinct invention. |
| Key deadline | Must be filed before the parent conventional application is granted. |
| Priority date | The original foreign priority date is preserved for all divided applications, a critical protection when foreign priority is at stake. |
| Who uses it | Applicants whose conventional application received a unity of invention objection, or who want to proactively split multiple inventions. |
The mechanics are the same as the Divisional Ordinary Application. One additional point applies here: the preserved priority date is the original foreign filing date. When that foreign date gives your Indian application its competitive advantage, acting before parent grant becomes especially critical.
Part C: The PCT Route (Types 7–9)
The following three types apply when a patent applicant has filed a PCT international application through WIPO and is now entering the Indian national phase. They are primarily used by foreign applicants and international IP counsel managing multi-jurisdiction filings. Indian applicants whose first filing was a PCT application will also encounter these types.
All three PCT types of patent application share one critical threshold: entry into the Indian national phase must be made within 31 months from the earliest priority date. India does not have a standard late-entry provision. Missing this deadline means the application cannot proceed in India.
| 7. PCT National Phase Application [For foreign applicants entering India via PCT] | |
| Statutory basis | Section 7(1A), Patents Act 1970 |
| Form | Form 1 + Form 2 (complete specification) + PCT documents |
| Key deadline | 31 months from the earliest priority date. No standard late entry. Restoration under Rule 137A of the Patents Rules is discretionary and not automatic, applicants should not rely on it. |
| Specification | Complete specification mandatory. A provisional specification cannot be filed for a PCT national phase application. |
| Documents required | Verified English translation of the PCT application (if not in English), priority document or WIPO DAS retrieval code, national phase entry fee per entity classification. |
| Examination | India is a designated International Searching Authority (ISA). Where the Indian IPO conducted the international search, the ISR and Written Opinion carry weight at national phase examination. |
| Who uses it | Foreign companies and inventors who filed a PCT international application and are designating India as a national phase country. |
In practice: The 31-month deadline runs from the earliest priority date in the PCT chain, not from the PCT filing date if a priority claim was made. In practice, applicants managing multiple national phase entries should track the earliest priority date separately, as it determines the deadline for every designated country simultaneously.
| 8. Divisional PCT National Phase Application [When your PCT national phase application covers more than one invention] | |
| Statutory basis | Section 16, Patents Act 1970 |
| Parent | An existing PCT national phase application in India that contains claims for more than one distinct invention. |
| Key deadline | Must be filed before the parent PCT national phase application is granted. Once the parent is granted, this window closes permanently. |
| Priority date | Same as the parent PCT national phase application. The original PCT international filing date (and any earlier priority date) is preserved for all divided applications. |
| No new matter | No new technical content may be introduced. The divisional must be based entirely on subject matter already disclosed in the parent PCT application. |
| Who uses it | Foreign applicants whose PCT national phase application in India received a unity of invention objection from the Controller, or who want to proactively split multiple inventions into separate Indian filings. |
The unity of invention rules and divisional mechanics are the same as for ordinary and conventional divisional applications. One key consideration applies specifically to PCT applicants. If the International Search Report or Written Opinion already raised a unity of invention objection, the Indian Controller is likely to repeat it at national phase examination. Filing a divisional proactively before examination, rather than waiting for a FER objection, avoids the risk of the parent being granted before the divisional is filed.
| 9. Patent of Addition for PCT National Phase Application [For improvements on an existing PCT national phase patent] | |
| Statutory basis | Section 54, Patents Act 1970 |
| Parent | An existing PCT national phase application (pending) or a granted PCT national phase patent in India. |
| Inventive step | Does not need to independently satisfy the full inventive step requirement. Only needs to be a genuine improvement or modification of the main invention. |
| Renewal fees | None. No separate annual renewal fees payable, the same cost saving that applies to patents of addition for ordinary and conventional applications applies here. |
| Expiry | Expires at the same time as the parent PCT national phase patent. It cannot outlive the main patent. |
| Who uses it | Foreign applicants holding a PCT national phase patent in India who are developing improvements to the patented invention and want to protect those improvements without paying separate renewal fees. |
In practice: For foreign applicants managing an international patent portfolio, patents of addition in India offer the same renewal-fee saving as they do for Indian domestic applicants. Where the parent patent was granted via PCT national phase, any improvement filed as a patent of addition inherits the parent’s PCT national phase status, there is no need to re-enter via PCT for the improvement.
For the full PCT national phase filing procedure — required documents, official fees, examination timeline, and deadline management — see: PCT Patent in India
Which Patent Application Type Do You Need? Quick Reference
Match your situation to the correct type of patent application in India. All deadlines shown are absolute.
| Your situation | File this type | Critical deadline |
| Filing in India first; invention still being refined | Ordinary Application (Provisional Specification) | File complete spec within 12 months of provisional, no extension |
| Filing in India first; invention fully documented | Ordinary Application (Complete Specification) | File RFE within 48 months of filing date |
| Improving an existing ordinary patent or application | Patent of Addition for Ordinary Application | Before parent ordinary patent expires |
| Ordinary application contains two or more distinct inventions | Divisional Ordinary Application | Before parent ordinary application is granted |
| Already filed in a Paris Convention country within the last 12 months | Conventional Application | 12 months from first convention country filing, strict |
| Improving an existing conventional patent or application | Patent of Addition for Conventional Application | Before parent conventional patent expires |
| Conventional application contains two or more distinct inventions | Divisional Conventional Application | Before parent conventional application is granted |
| Entering India via PCT international application (foreign applicants / Indian PCT filers) | PCT National Phase Application (Type 7) — see Part C of this guide | 31 months from earliest priority date — strict, no standard late entry |
5 Patent Application Mistakes That Cost Inventors Their Priority Date
Mistake 1: Missing the 12-month deadline to complete an ordinary patent application
This is the most common and most costly error for Indian inventors. If you file a provisional specification and do not file the complete specification within 12 months, the application is automatically abandoned under Section 9(1). There is no extension and no revival mechanism. The priority date is permanently lost. Set a hard reminder the day you file — not at 11 months, earlier.
Mistake 2: Filing a provisional specification for the wrong application type
Provisional specifications are only available for ordinary applications where India is the first-filing country. They cannot be filed for conventional applications, PCT national phase applications, divisional applications of any type, or patents of addition of any type. Using the wrong specification type will cause the IPO to reject or incorrectly process the application.
Mistake 3: Missing the divisional window before the parent is granted
Once the Controller grants the parent patent, the window for this type of patent application closes permanently. If the Controller raised a unity of invention objection and you did not file a divisional before grant, the additional inventions cannot be separately protected. Monitor examination status actively and act on unity objections before responding to the FER.
Mistake 4: Confusing the convention priority window with the RFE deadline for a conventional patent application
The 12-month convention priority window runs from your first foreign filing date and determines whether you can claim that date as your Indian priority date. The 48-month Request for Examination (RFE) deadline runs from the Indian filing or priority date and determines whether your application proceeds to examination at all. These are entirely separate deadlines with entirely separate consequences.
Mistake 5: Introducing new matter in a divisional application
A divisional application must be based entirely on subject matter already disclosed in the parent application at the time of filing. New technical content cannot be added at the divisional stage, even if you have made further improvements. Any new material requires a separate application with its own priority date.
A Note on Filing Fees
Official government filing fees for each type of patent application depend on your entity classification: natural person, startup, small entity, or large entity. Startups and small entities pay significantly reduced fees — typically 80% less than the large entity rate, under the Patents Amendment Rules, 2021.
Estimate current government fees for your specific type and entity class using the Intepat Patent Fees Calculator.
Choosing the Right Patent Application Type in India
The Indian Patent Office lists 9 types of patent applications on Form 1, organised across three filing routes: ordinary, conventional, and PCT national phase. Each route contains three sub-types: a first-time filing, a patent of addition for improvements, and a divisional for splitting multi-invention applications. The right choice across all nine types comes down to the same two questions asked for each route: where was the first filing made, and is this a first-time filing, an improvement, or a split?
Across all types of patent application, the pattern is consistent: deadlines are absolute, specification choices are locked at filing, and the divisional window closes the moment the parent is granted. Getting these decisions right before filing, not after is what protects the priority date you have worked to establish.
For the full filing procedure, see Patent Filing Procedure and Process in India. For drafting guidance, see Understanding the Patent Specification of an Invention.
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FAQs: Types of Patent Applications in India
There are 9 types of patent applications in India, listed on IPO Form 1 across three filing routes. They are: Ordinary Application, Conventional Application, PCT National Phase Application, Patent of Addition for Ordinary Application, Patent of Addition for Conventional Application, Patent of Addition for PCT National Phase Application, Divisional Ordinary Application, Divisional Conventional Application, and Divisional PCT National Phase Application.
You file an ordinary application when India is your first filing country and you have no earlier foreign application to claim priority from. You file a conventional application when you have already filed in a Paris Convention member country within the past 12 months and want to claim that earlier date as your Indian priority date. Both require a complete specification. Only ordinary applications may be filed with a provisional specification first.
No. Among the 9 types of patent applications in India, provisional specifications are available only for ordinary applications where India is the first-filing country. Conventional applications, PCT national phase applications, divisional applications of any type, and patents of addition of any type must all be filed with a complete specification.
The application is automatically deemed abandoned under Section 9(1) of the Patents Act, 1970. There is no grace period, no extension, and no revival mechanism. The priority date established by the provisional filing is permanently lost.
These two types of patent application serve entirely different purposes. A patent of addition protects an improvement or modification to an existing patent or application. It does not require independent inventive step and attracts no separate renewal fees, but it expires when the parent patent expires. A divisional application is used when a single application covers two or more distinct inventions, you split it to protect each invention separately, each retaining the parent’s priority date. Both serve different purposes and have different eligibility conditions.
No. A divisional application must be filed before the parent patent is granted. Under Section 16 of the Patents Act, once the parent is granted, the divisional window is closed permanently and cannot be reopened.
The correct type of patent application is a conventional application. You have a 12-month window from your US filing date to file in India and claim the US date as your Indian priority date. You will need a complete specification (provisional is not available for conventional applications) and a certified copy of the US application, or retrieve it electronically via WIPO DAS.
Under Section 6 of the Patents Act, 1970, applications may be filed by the true and first inventor, an assignee of the inventor, or the legal representative of a deceased inventor. Applications may be filed individually or jointly. There is no nationality restriction; foreign individuals and companies may file directly or through a registered Indian patent agent.
The deadline is 31 months from the earliest priority date in the PCT application chain. This is a strict deadline; India does not have a standard late-entry provision equivalent to those in some other jurisdictions. Where the PCT application claimed priority from an earlier national filing, the 31-month clock runs from that earlier priority date, not from the PCT international filing date. Applicants managing multiple national phase entries should track this priority date carefully, as it sets the national phase deadline for every designated country simultaneously.
Legal Disclaimer
This post is for informational purposes only and does not constitute legal advice. Statutory provisions are cited for reference based on the Patents Act, 1970 and Patents Rules, 2003 as amended to March 2026. Laws and procedures may change; verify current requirements with a registered patent agent before acting.