By Lucy Rana and Huda Jafri
Introduction
One of the most common beliefs among founders and first-time inventors is that there is something called an “international patent,” a single filing that protects an invention across the world.
It sounds simple: file once, get global protection, and focus on building the business. But patent law does not work that way.
It is territorial by design. Rights do not travel across borders, and there is no world patent. Instead, every patent is granted country by country. What the international system offers is not a global right, but two routes that help you reach multiple national patents: the Paris Convention route and the PCT route.
Both start with a first filing, usually in India, that fixes a priority date. Both end with patents being granted, refused, or abandoned in individual countries. The difference lies in what happens in between.
For Indian applicants, this is not a routine filing step. It is a strategic decision that affects cost, timing, and business direction.
There is no world patent. Only national patents and the routes that lead to them.
The Common Misunderstanding
Ask founders how they plan to protect an invention internationally, and many will say they are “filing a PCT” or already have an “international patent.”
Neither is correct.
Patent rights are always territorial. Each country or region grants and enforces its own patents under its own laws.
The international system only provides procedural routes that help you file in multiple countries more efficiently. These ultimately lead to separate national patents through two paths: the Paris Convention and the PCT.
Both begin with a first filing, usually in India, which creates a priority date. Both end with separate national patents. The difference is in the path between these two points.
This is not a decision to be made casually at the 12-month mark. It should align with the commercial strategy of the invention.
There is no world patent. Only national patents and the routes that lead to them.
Before Anything Else: The Section 39 Rule (India Filing Restriction)
Before thinking about international filings, Indian applicants must deal with an important legal requirement that is often missed.
Section 39 of the Patents Act, 1970 says that a person resident in India cannot file a patent outside India without permission from the Indian Patent Office, unless:
- The invention has already been filed in India at least six weeks earlier, or
- A Foreign Filing Licence has been obtained.
In simple terms, there are two options:
- File in India first and wait six weeks before filing abroad
- Obtain a Foreign Filing Licence and then file directly outside India, including a PCT application
This step is frequently missed in startup workflows, especially when foreign counsel or accelerators are involved early.
If this rule is violated, the consequences are serious. The Indian application can be treated as abandoned, and any granted patent can later be challenged. There are also possible penalties, including fines and imprisonment in serious cases.
A safe assumption is this: if any inventor is resident in India, Section 39 should be treated as relevant unless a qualified patent attorney advises otherwise.
The Two Routes Explained Clearly
The Paris Convention Route
The Paris Convention allows an applicant to take a first patent filing and extend it to other countries within 12 months, while keeping the same priority date.
In this route, separate applications are filed in each country that matters, such as India, the United States, or the European Patent Office. Each country then handles the application independently under its own law.
There is no shared international application. Everything happens country by country from the beginning.
The PCT Route
The Patent Cooperation Treaty (PCT), managed by WIPO, allows filing a single international application within the same 12-month window.
This does not result in an international patent. Instead, it keeps options open in more than 150 countries and delays the decision of where protection will actually be pursued.
The process has two stages:
- International stage, which includes search, written opinion, and publication
- National stage, where the application enters selected countries for prosecution
Most countries require national phase entry at around 30 or 31 months from the priority date.
This extended timeline is one of the most important differences between the two routes.
The Real Decision Point: 12 Months vs 30 Months
Both routes begin with the same 12-month deadline. Within this period, the applicant must choose:
- File separately in countries (Paris route), or
- File one PCT application (PCT route)
After 12 months, the paths diverge.
With the Paris route, the applicant must already know which countries matter and fund all filings within that year.
With the PCT route, one filing preserves options and defers country selection until national phase entry, usually at 30 or 31 months. This gives around 18 additional months of flexibility.
Missing the 12-month deadline is generally fatal for claiming priority, although limited restoration may exist in some jurisdictions under strict conditions. Practically, it should always be treated as a hard deadline.
What the PCT Route Actually Gives You
The PCT system provides four main advantages:
- Time
It delays the country selection decision by about 18 months, allowing time to:- Assess commercial traction
- Raise funding
- Identify licensing or partnership opportunities
- Evaluate market relevance
- Early Technical and Legal Insight
The International Search Report and Written Opinion provide an early view of:- Novelty
- Inventive step
- Relevant prior art risks
- Flexibility to Improve the Application
The system allows claim amendments during the international phase, helping refine the application before entering countries. - Wider Optionality
A single filing keeps access open to more than 150 countries, with national costs incurred only where protection is ultimately pursued.
Why Some Applicants Prefer the Paris Route
The Paris route is not inferior. It simply fits a different strategy.
- Faster Movement in Some Countries
Since filings go directly into national systems, examination can begin earlier, depending on jurisdiction. - More Direct Control
The applicant works with each country from the start instead of going through an international phase first. - Lower Cost When Markets Are Known
If only one or a few countries matter, the PCT route may add unnecessary international costs.
How to Decide Between the Two
The decision depends on four factors:
- Certainty of markets: known markets favor Paris, uncertain markets favor PCT
- Cash flow timing: immediate budget favors Paris, deferred spending favors PCT
- Speed needs: urgent grant favors Paris, flexible timeline favors PCT
- Need for early patentability insight: high need favors PCT, low need favors Paris
Simple rule:
- Few countries and clear markets → Paris route
- Many countries or uncertainty → PCT route
The Cost Most People Do Not Plan For
A common mistake is focusing only on the initial filing cost.
A PCT application looks affordable at first, but the real costs come later at national phase entry. These include:
- Local attorney fees
- Government fees
- Translation costs
- Country-specific prosecution costs
These costs arrive together at around 30 or 31 months and can become significant if multiple countries are selected.
The Paris route does not remove these costs. It simply brings them forward to the 12-month mark.
So the real issue is not cost itself, but timing and cash flow planning.
Conclusion: This Is a Business Decision, Not Just a Legal One
Choosing between the Paris Convention route and the PCT route is not just a filing decision. It is a way of managing time, money, and uncertainty.
The Paris route works best when markets are already known and speed matters.
The PCT route works best when there is uncertainty and a need for flexibility and information before committing.
But both systems lead to the same reality: patents are always national.
The most important decision is not which route you choose, but whether you are thinking about it early enough to choose properly.
Because once the 12-month deadline passes, the system does not ask what you intended to do. It reflects what you already decided.