Intellectual Property Rights - Law and Practice · Role of International Institutions

Patent Cooperation Treaty and Budapest Treaty Explained

Updated 11 October 2026 · Fact-checked

The Patent Cooperation Treaty (PCT) lets you file one international application that gives you a filing date in all member states. It has an international phase (filing, search, publication, optional preliminary examination) and a national phase, where each country decides on grant. The Budapest Treaty recognises one deposit of a microorganism for patent purposes in all member states.

Understand Patent Cooperation Treaty and Budapest Treaty

A patent is territorial. A Indian patent gives no right in the USA or Germany. Without a common system, you would have to file a separate application in every country, almost at once, to protect an invention abroad. That is costly and rushed.

The Patent Cooperation Treaty (PCT) solves the filing problem. It is administered by WIPO and concluded in 1970. It does not grant an "international patent". It creates one standard application, with one filing date, that is effective in all contracting states. Grant stays with each national or regional office.

The PCT works in two phases. In the international phase, you file the application, an International Searching Authority prepares an international search report and a written opinion, and WIPO publishes the application, normally 18 months from the priority date. You may also ask for an international preliminary examination (Chapter II). In the national phase, you enter each country where you want protection, within the time limit set under the Treaty, which is generally 30 months from the priority date, though some offices allow longer. Each office then examines under its own law.

In India, the Patents Act, 1970 and the Patents Rules, 2003 give effect to the PCT. The Indian Patent Office can act as receiving office, International Searching Authority and International Preliminary Examining Authority. An Indian applicant can file an international application at the Indian Patent Office as receiving office. Check the current Rules for the exact filing requirements, including the security and foreign-filing permission rules for inventions made in India.

The Budapest Treaty solves a different problem. Some inventions use a microorganism that cannot be described in words well enough for someone else to repeat the invention. The patent then needs the organism itself to be available. Without the Treaty, you would deposit the culture in every country where you file. Under the Treaty, a single deposit with one International Depositary Authority (IDA) is recognised by all contracting states for patent procedure. The deposit is made before or at the time of filing, and the depositary issues a receipt and later a viability statement. Samples are released to third parties only under the conditions set by the Treaty and national law.

Key rules to remember

PCT in one line: One international application + one filing date → effective in all PCT contracting states; It is a filing system, not a grant. No international patent is issued.
Phases of the PCT: International phase (filing, search, publication, optional preliminary examination) → National phase (entry, examination, grant by each office); Grant or refusal is decided only in the national phase.
Publication timing: International publication ≈ 18 months from the priority date; Applicant may request earlier publication.
National phase entry: Generally 30 months from the priority date; Some national laws allow a longer period. Check the office concerned.
Budapest Treaty rule: One deposit with one International Depositary Authority = recognised in all contracting states for patent procedure; Applies only to microorganisms. Deposit proves availability of the organism.
Who administers: PCT and Budapest Treaty are both administered by WIPO; WIPO's International Bureau handles publication and communications.

How to solve Patent Cooperation Treaty and Budapest Treaty questions

Use this method for any question on the PCT or the Budapest Treaty, whether it is a theory question or a case-based one.

1Identify what is asked: filing route, phase, timeline, or microorganism deposit.
2State the treaty and its purpose in one or two lines (PCT: single filing; Budapest: single deposit).
3For PCT, lay out the phases in order: international phase, then national phase. Name the key step in each.
4Apply the facts: note the priority date, where the applicant is, and the countries where protection is wanted. Compute the 12-month and 30-month points from the priority date.
5For microorganisms, check whether the invention depends on a culture that cannot be described fully. If yes, a deposit with an IDA is needed.
6State who decides: the national office decides grant, not WIPO or the searching authority.
7Conclude with a clear advice to the applicant, with the next action and date.

Quickest way: Phase-and-date check

When to use it: When a case question gives a priority date and asks what the applicant should do next.

Write the priority date.
Mark 12 months for a convention or PCT filing claiming priority.
Mark about 18 months for publication.
Mark 30 months for national phase entry, subject to the office's rule.
For a microorganism, add: deposit with an IDA on or before filing, and get the receipt.
Close with: grant is by each national office.

Common mistakes in Patent Cooperation Treaty and Budapest Treaty

Writing that the PCT grants an international patent.
The name sounds like a single global right.
Fix: Say the PCT gives a single filing procedure. Each country grants its own patent.
Mixing up the international and national phases.
Students memorise steps without grouping them.
Fix: Put search, publication and optional preliminary examination under the international phase. Put entry, examination and grant under the national phase.
Stating the Budapest Treaty covers all biological material or all patents.
The word deposit is read broadly.
Fix: Limit it to microorganisms deposited for patent procedure with an International Depositary Authority.
Saying one Budapest deposit gives a patent in every country.
Confusing recognition of deposit with grant.
Fix: The Treaty only removes the need for a separate deposit in each state. Patentability is decided nationally.
Quoting 30 months as an absolute rule for all countries.
The figure is a common rule of thumb.
Fix: Say it is generally 30 months from priority, and that some national laws allow a different period.
Ignoring the Indian angle in a case question.
Students answer only on the treaty text.
Fix: Mention that the Indian Patent Office can act as receiving office and that the Patents Act, 1970 and Rules give effect to the PCT.

Worked examples

Example 1

Aarav Biotech Pvt Ltd, Pune, files an Indian patent application on 10 March 2027. It wants protection in several countries. Explain how it can use the PCT and the main stages.

Show the solution

Treat 10 March 2027 as the priority date.
The company can file a PCT international application within 12 months of this date, that is by 10 March 2028, claiming priority. It may file at the Indian Patent Office as receiving office.
International phase: an International Searching Authority prepares a search report and written opinion. The application is published by WIPO about 18 months from priority, that is around September 2028. The company may also request international preliminary examination.
National phase: the company must enter each chosen country within the time limit, generally 30 months from priority, that is around 10 September 2029, subject to the rule of each office.
Each national office then examines the application under its own law and decides on grant.

Answer: Aarav Biotech files one PCT application by 10 March 2028, goes through search and publication in the international phase, and enters each chosen country in the national phase, generally by about 10 September 2029. Each country decides on grant. No international patent is issued.

Example 2

Dr Meera Nair develops a vaccine process using a new bacterial strain that cannot be fully described in writing. She plans to file patents in India and in other countries. Advise on the Budapest Treaty.

Show the solution

Identify the issue: the invention depends on a microorganism whose description cannot let others repeat it. Availability of the culture is therefore needed.
Without the Treaty she would deposit the strain in every country of filing.
Under the Budapest Treaty she can deposit the strain once with an International Depositary Authority, on or before the filing date.
The depositary issues a receipt and later a viability statement. She should cite the deposit details in the application.
The deposit is recognised in all contracting states for patent procedure. Samples are released to others only on the conditions allowed by the Treaty and national law.
Patentability is still decided by each national office.

Answer: Dr Nair should deposit the strain with one International Depositary Authority before or at filing, obtain the receipt and refer to it in her applications. One deposit is recognised in all contracting states for patent procedure, but each office still decides on grant.

Exam tips

Draw the two phases as a short flow in your answer. It scores clarity marks and saves time.
In case questions, compute the 12-month, 18-month and 30-month points from the priority date and show them.
Always add that grant stays with national offices. Examiners look for this line.
For the Budapest Treaty, name the three items: microorganism, International Depositary Authority and recognition in all contracting states.
Link both treaties to WIPO and to the Patents Act, 1970 in one closing line.

Practice questions from Role of International Institutions

Patent Cooperation Treaty and Budapest Treaty: frequently asked questions

What are the phases of the PCT?

There are two. The international phase covers filing, international search, publication and optional preliminary examination. The national phase is where you enter each country and its office examines and grants under national law.

Can I file a PCT application from India?

Yes. An Indian applicant can file an international application at the Indian Patent Office, which acts as receiving office. Check the current Patents Rules for forms, fees, language and any permission needed for inventions made in India.

Does the PCT give a worldwide patent?

No. It gives a single filing procedure and filing date in all member states. Each country or regional office decides whether to grant a patent.

Why is the Budapest Treaty needed?

Some inventions rely on a microorganism that cannot be described fully in words. The Treaty lets you deposit it once with an International Depositary Authority, and that deposit is recognised in all contracting states for patent procedure.