Exploring the Different Types of Patent Applications in India

When an inventor creates something new, the first instinct is to protect it. But before that protection can begin, there is one critical decision to make: which type of patent application should be filed? Under the Patents Act, 1970, India offers several distinct types of patent applications, each designed for a specific situation. Whether you are a first-time filer, an inventor who has already filed abroad, or someone looking to protect an improvement to an existing patent, there is a route built for your circumstances. Understanding these options is not just procedurally important – it directly affects the strength and timing of your patent protection.

The first-to-file rule and why application type matters 🔗

India follows a first-to-file system, which means that patent rights belong to whoever files the application first – not necessarily whoever invented first. This makes early and correct filing critical. Choosing the wrong type of application can cost an inventor their priority date, create procedural complications, or even result in abandonment of the application. The Patents Act, 1970 provides for multiple application types to accommodate different stages of invention and different geographic contexts.

Ordinary application 🔗

An ordinary application is the most straightforward route. It is filed directly with the Indian Patent Office (IPO) without claiming any priority from a previously filed application – whether in India or abroad. This type of application does not reference any other pending application and must be accompanied by a complete specification and claims.

An ordinary application can be filed in two ways. First, as a provisional application when the invention is still being developed but the inventor wants to secure an early filing date. A provisional application does not require full claims or a complete specification. It simply establishes the priority date and gives the inventor 12 months to file a complete specification. If the complete specification is not filed within this 12-month window, the application is deemed abandoned. During this period, the inventor can use the phrase “Patent Pending.”

Second, when the invention is fully developed, a complete (non-provisional) application can be filed directly with all required documents – a detailed specification, drawings, and properly drafted claims. This is typically the first patent filing for an invention and is immediately subject to examination by the Patent Office.

Convention application 🔗

Suppose an Indian startup files a patent application for a new drug delivery system in the United States. Six months later, the startup wants the same invention protected in India too. They do not need to start from scratch. This is exactly what a convention application is designed for.

Governed by Section 135 of the Patents Act, 1970, a convention application allows an applicant to claim the priority date of an earlier application filed in a convention country – a country that has signed a bilateral or multilateral agreement with India recognising such priority claims. The applicant must file the convention application in India within 12 months from the date of the first application filed in the convention country. The key benefit is that the Indian application is treated as if it were filed on the original foreign filing date, protecting the inventor from intervening disclosures or competing applications filed in the interim.

If applications have been filed in two or more convention countries, the 12-month period runs from the date of the earliest such application. The applicant must also furnish certified copies of the foreign specification and, if documents are not in English, their translated versions.

PCT national phase application 🔗

For inventors seeking protection in multiple countries simultaneously, the Patent Cooperation Treaty (PCT) route offers a streamlined alternative to filing separate applications in each jurisdiction. Administered by the International Bureau of WIPO, the PCT system allows a single international application to serve as the basis for patent protection in over 150 member countries.

India became a contracting state to the PCT on December 7, 1998. The process involves two phases: an international phase and a national phase. During the international phase, a single PCT application is filed, and an international prior art search is conducted. The national phase begins when the applicant decides to pursue protection in specific countries. For India, the PCT national phase application must be filed within 31 months from the earliest priority date. A 2024 amendment now also permits an extension of up to 6 months beyond this deadline with payment of an extension fee.

Once the application enters the national phase, it is treated like a regular Indian patent application and examined under the Patents Act, 1970. Most formal requirements are completed during the international phase, which makes national phase entry relatively simpler. However, foreign applicants must file through a registered Indian patent agent, and the application must correspond exactly with what is publicly available in WIPO records at the time of filing. Unlike most jurisdictions, the Indian Patent Office does not allow amendments to the application at the time of national phase entry – any required changes must be filed subsequently.

PCT vs. convention application: what’s the difference? 🔗

Both the PCT route and the convention application route allow an inventor to claim a foreign priority date in India. The key difference lies in scope and strategy. A convention application is a direct bilateral filing in India claiming priority from one or more convention country applications. A PCT national phase application uses the PCT system as an intermediate step, allowing the applicant to defer country-specific decisions for up to 31 months while keeping options open across multiple jurisdictions. The PCT route is particularly useful when the commercial potential of the invention across different markets is still being evaluated.

Divisional application 🔗

Under Section 10(5) of the Patents Act, 1970, each patent application must relate to a single invention – this is the principle of unity of invention. If a patent application discloses more than one invention, either the applicant or the Patent Office (acting through the Controller) may require the application to be split into separate applications. Each of these split applications is called a divisional application.

The date of filing of the original application is treated as the date of filing for all divisional applications, preserving the same priority date across all. Each divisional application is then treated independently and examined on its own merits. Importantly, a divisional application cannot contain any matter that was not disclosed in the original (parent) application. This mechanism ensures that inventors do not lose protection over distinct inventions simply because they were initially combined in a single filing.

Patent of addition 🔗

Inventions are rarely static. After a patent is filed or granted, an inventor often develops improvements or modifications to the original invention. If these improvements do not independently qualify as a new invention – because they lack novelty or an inventive step on their own – they cannot be the subject of a fresh ordinary patent application. The patent of addition is the legal mechanism designed for exactly this situation.

Governed by Sections 54 to 56 of the Patents Act, 1970, a patent of addition can be filed when an improvement or modification is made to an invention that is already the subject of a pending application or a granted patent (referred to as the main patent or parent application). Key features of this application type include:

• The application must contain a reference to the main patent or parent application.
• A patent of addition is only granted if the main patent is valid and in force.
• If the parent application is rejected, the patent of addition application is also rejected.
• According to Sections 54 and 55, a patent of addition is treated as a standalone patent – it receives its own application number and is separately published after 18 months.
• The patent of addition expires with the main patent, so it does not extend the overall period of protection beyond the original 20-year term.

This provision is especially useful in industries where inventions go through iterative development cycles – such as pharmaceuticals, electronics, and manufacturing processes. In the United States, a similar concept exists under the label of continuation or continuation-in-part (CIP) applications.

Choosing the right application type 🔗

Selecting the appropriate type of patent application is a strategic decision, not just an administrative one. The table below summarises when each type is most appropriate:

Each of these application types reflects a deliberate policy choice by the Indian legislature to accommodate the practical realities of invention – whether an idea is still evolving, needs international reach, contains multiple innovations, or builds upon earlier work. The legal framework under the Patents Act, 1970 is designed to be flexible enough to protect inventors at every stage of their journey, while maintaining the rigour needed to ensure that only genuinely new and useful inventions receive exclusive rights.

What do you think? If an inventor files a provisional application but their invention evolves significantly before the complete specification is due, should the improvement be covered in the same application or filed as a patent of addition? And given India’s first-to-file system, how early is “early enough” when it comes to securing your priority date?

References

1. https://www.wipo.int/wipolex/en/text/128091
2. https://lawbhoomi.com/types-of-patent-applications-in-india/
3. https://yourpatentteam.com/patent-application-types-india/
4. https://ssrana.in/ip-laws/patents/patent-applications-in-india/
5. https://practiceguides.chambers.com/practice-guides/patent-litigation-2025/india/trends-and-developments
6. https://www.intepat.com/blog/pct-patent-india
7. https://www.aipla.org/list/innovate-articles/entering-the-national-phase-of-patent-applications-in-india-under-the-patent-cooperation-treaty
8. https://blog.ipleaders.in/types-of-patent-applications-in-india/
9. https://acuraip.com/types-of-patent-applications-in-india/