1. What Is a PCT Patent Application?
A PCT application is an international patent application filed under the Patent Cooperation Treaty.
It allows a qualifying applicant to begin seeking patent protection across PCT Contracting States through a centralized international filing procedure.
During the international phase, the application may undergo:
Formal review by the receiving office.
International prior-art searching.
A written opinion concerning potential patentability.
International publication.
Optional international preliminary examination.
The applicant later determines which national or regional patent systems to enter.
Those individual patent offices then apply their own laws and decide whether patents should ultimately be granted.
A PCT application is therefore best understood as:
A centralized international patent filing and evaluation process, not an international patent grant.
2. Does a PCT Application Create an International Patent?
No.
There is no single worldwide patent issued through the PCT.
WIPO administers the international application process, but actual patents are granted by national or regional patent offices.
Depending on the applicant’s strategy, later patent prosecution might occur before:
The United States Patent and Trademark Office.
The European Patent Office.
The Canadian Intellectual Property Office.
The Japan Patent Office.
The China National Intellectual Property Administration.
Other participating national or regional patent offices.
Each office applies the substantive patent law and procedures governing its jurisdiction.
The international search and written opinion can provide valuable information, but those findings are not legally binding on national patent offices.
A PCT application therefore preserves international patent options.
It does not replace national or regional patent prosecution.
3. What Countries Are Covered by the PCT?
As of September 2026, the PCT has 159 Contracting States.
The system includes most major global patent markets, but it does not include every country or territory.
An international patent strategy should therefore distinguish among:
PCT Contracting States.
Non-PCT jurisdictions requiring direct filing.
Regional patent systems accessible through the PCT.
Countries with specialized filing or priority requirements.
Treaty membership can change.
For a particular filing, the current PCT Contracting States and available regional routes should be confirmed before the applicable deadline.
4. Do You Have to Select Countries When Filing a PCT Application?
Generally, no.
Under the modern PCT designation system, filing the PCT request generally constitutes designation of all Contracting States bound by the Treaty on the international filing date.
The applicant therefore ordinarily does not need to choose each individual PCT country at the initial filing stage.
Instead, the PCT preserves broad filing options.
The applicant later decides which national or regional systems are commercially important enough to enter.
This postponement is one of the PCT’s principal strategic advantages.
It provides additional time to determine:
Where the product will be sold.
Where competitors operate.
Where manufacturing will occur.
Which markets generate meaningful revenue.
Where licensing opportunities exist.
Which jurisdictions justify foreign patent expenses.
5. Who Can File a PCT Application?
The PCT is generally available where at least one applicant is a national or resident of a PCT Contracting State.
Where an international application has multiple applicants, one qualifying applicant can generally satisfy the nationality or residence requirement for access to the PCT system.
Nationality and residence can also affect:
Which receiving office is competent.
Which International Searching Authorities are available.
Representation requirements.
Filing procedures.
For a company, place of organization may be important.
For an individual, nationality and residence may affect filing options.
Applicant identity should therefore be reviewed before filing.
6. Where Is a PCT Application Filed?
A PCT application is filed with a competent receiving office.
For qualifying U.S. applicants, the USPTO can act as the PCT Receiving Office.
Depending on the applicant’s nationality and residence, filing may also be possible through the International Bureau of WIPO acting as Receiving Office, commonly referred to as RO/IB.
The correct receiving office can depend on:
Nationality.
Residence.
Filing language.
Applicable national-security requirements.
Available International Searching Authorities.
Foreign-filing restrictions.
For inventions made in the United States, U.S. foreign-filing and national-security requirements should be considered before filing directly with a foreign patent office or WIPO.
The receiving office should therefore be selected strategically rather than solely for convenience.
7. When Must a PCT Application Be Filed?
If the applicant wants the PCT application to claim priority to an earlier patent filing, the ordinary priority period for an invention is generally 12 months from the earliest priority filing date.
For example:
Month 0: U.S. provisional application filed.
By Month 12: PCT application filed claiming priority to the provisional application.
When properly filed and adequately supported, later patent claims may receive the benefit of the earlier priority date.
Without the PCT, an applicant seeking Paris Convention priority would generally need to pursue applicable direct foreign filings within the same basic 12-month priority period.
The PCT changes what happens after that point.
Instead of immediately entering numerous national patent systems at approximately month 12, the applicant can generally postpone many national-phase decisions until approximately month 30 from the priority date.
Limited procedures for restoring a missed priority period may exist in qualifying circumstances, but they should not be treated as a routine substitute for timely filing.
8. Can a PCT Application Claim Priority to a U.S. Provisional Application?
Yes.
This is a common strategy for U.S. inventors, startups, and technology companies.
A typical timeline may look like:
Month 0: U.S. provisional application filed.
Months 1 through 11: Product development, testing, financing, commercialization, and additional patent work.
By Month 12: PCT application filed claiming priority to the provisional application.
Around Month 18 from priority: International publication.
Around Month 30 from priority: National-phase deadlines begin in many jurisdictions.
The important qualification is that the provisional filing date benefits only subject matter adequately disclosed in that provisional application.
If substantial new technology was developed after the provisional filing, it may be included in the PCT application.
But newly added subject matter does not automatically receive the earlier provisional filing date.
The quality of the original provisional application can therefore have significant consequences for international patent strategy.
Learn About Provisional Patent Applications
9. What Must a PCT Application Include?
A PCT application is a substantive patent application.
It is not merely a form requesting additional time.
A PCT international application generally includes:
A request.
A description.
One or more patent claims.
Drawings where required.
An abstract.
The description should disclose the invention sufficiently clearly and completely for a person skilled in the relevant field to carry it out.
A PCT application is therefore materially different from a U.S. provisional application.
A provisional application does not require formal patent claims and does not undergo an international search.
A PCT application contains claims and enters a structured international patent process.
The disclosure should be prepared with future national-phase prosecution in mind because the same application may later form the basis for patent prosecution in numerous jurisdictions.
10. What Happens During the International Phase?
The PCT process can be divided broadly into two stages.
International Phase
The applicant files the PCT application.
The receiving office reviews formal requirements.
An International Searching Authority conducts a prior-art search.
The applicant receives an International Search Report.
The applicant receives a written opinion.
The application is ordinarily published by WIPO.
Certain claim amendments may be available.
Optional international preliminary examination may be requested.
National or Regional Phase
The applicant determines where patent protection should actually be pursued.
The applicant then complies with the requirements of the selected national or regional patent offices.
Those requirements may include:
Government fees.
Translations.
Local counsel.
National forms.
Patent claims.
Priority documents.
Examination requests.
Other formalities.
Each office then evaluates the application under its own patent law.
The international phase centralizes the early portion of international patent filing.
It does not eliminate the later country-specific patent process.
11. What Is the International Search Report?
A PCT application generally undergoes a prior-art search conducted by an International Searching Authority, commonly abbreviated ISA.
The International Searching Authority identifies patent documents and other prior art considered relevant to the claims.
The resulting document is called the International Search Report, or ISR.
Potential references can include:
Earlier patents.
Published patent applications.
Foreign patent documents.
Technical literature.
References relevant to novelty.
References relevant to inventive step.
The International Search Report does not grant or deny a patent.
Instead, it provides information that can help the applicant decide:
Whether the application remains commercially worthwhile.
Whether claim amendments may be appropriate.
Which jurisdictions should be pursued.
Whether additional patentability analysis is needed.
How national-phase prosecution may develop.
The particular International Searching Authority available can depend on the receiving office and other PCT rules.
12. What Is the Written Opinion of the International Searching Authority?
Along with the international search, the applicant generally receives a Written Opinion of the International Searching Authority, commonly called the WO/ISA.
The written opinion provides a preliminary assessment of matters including:
Novelty.
Inventive step.
Industrial applicability.
Other relevant PCT requirements.
The written opinion is informative rather than final.
National and regional patent offices are not legally required to reach the same conclusion.
A favorable written opinion does not guarantee that every selected patent office will grant a patent.
An unfavorable opinion also does not automatically mean all national-phase filings should be abandoned.
The applicant can review the cited prior art, consider available amendments, evaluate optional international preliminary examination, and determine which jurisdictions remain worth pursuing.
13. When Is a PCT Application Published?
A PCT application is generally published by WIPO shortly after 18 months from the priority date.
International publication typically includes:
Bibliographic information.
The description.
Patent claims.
Drawings.
The abstract.
The International Search Report when available.
Published PCT applications become searchable through WIPO’s PATENTSCOPE database.
Publication has an important strategic consequence.
Applicants should generally expect the technical disclosure contained in the PCT application to become public.
Patent strategy and trade-secret strategy should therefore be coordinated before commercially sensitive information is disclosed in the application.
14. What Is International Preliminary Examination?
International preliminary examination is an optional procedure available during the PCT process.
It is sometimes referred to as Chapter II examination.
The applicant may request examination by an International Preliminary Examining Authority.
The process can provide:
Additional patentability analysis.
Consideration of qualifying amendments.
Additional information before national-phase decisions are finalized.
The resulting report does not create a binding worldwide determination of patentability.
National and regional patent offices retain authority to decide whether a patent should issue under their own laws.
Chapter II examination can be useful in particular cases, but its value should be considered in light of:
International search results.
Planned jurisdictions.
Prosecution strategy.
Available amendments.
Timing.
Cost.
15. What Is the PCT National Phase?
The national phase is the stage when the applicant moves from the centralized PCT international process into individual national or regional patent systems.
At this point, the applicant determines where patent rights are actually worth pursuing.
For example, an applicant might choose to enter:
The United States.
Canada.
Japan.
China.
Australia.
A European regional patent route.
Other selected national or regional jurisdictions.
National-phase entry may require:
Government filing fees.
Translations.
Foreign or local patent counsel.
Patent-office forms.
Patent claims.
Inventor documentation.
Priority documentation.
Examination fees.
Other national formalities.
The exact requirements vary by jurisdiction.
Once national phase begins, each patent office handles examination under its own substantive patent laws and procedures.
16. What Is the 30-Month PCT Deadline?
The PCT commonly postpones national-phase filing until approximately 30 months from the priority date.
Some patent offices use a 31-month deadline, while other specialized rules can apply.
The correct deadline should therefore be confirmed separately for each intended jurisdiction.
Applicants should not assume that:
Every jurisdiction uses exactly 30 months.
Every jurisdiction uses exactly 31 months.
Late national-phase entry will always be available.
The practical advantage can be significant.
Where an applicant files a PCT application around month 12 after an earlier priority application, the PCT may provide approximately another 18 months before many country-specific filing expenses become due.
During that period, the applicant can evaluate:
International search results.
Product-market fit.
Revenue.
Fundraising.
Licensing opportunities.
Manufacturing plans.
Competitors.
Target countries.
Commercial value.
Patent budget.
The PCT does not eliminate foreign patent costs.
It postpones many of them until the applicant has more information.
17. What Is the Difference Between PCT Filing and Direct Foreign Filing?
An applicant does not have to use the PCT to pursue international patent protection.
Two principal strategies may be considered.
Direct Foreign Filing
The applicant files directly in selected foreign jurisdictions within the applicable priority period.
This may be appropriate where only a small and clearly defined group of countries matters and the applicant is prepared to incur those filing costs relatively early.
PCT Filing
The applicant files one international application within the applicable priority period.
The PCT preserves broad options across participating jurisdictions and generally postpones national-phase decisions and many country-specific expenses.
Neither approach is automatically better.
The appropriate strategy can depend on:
Number of countries.
Commercial certainty.
Patent budget.
Translation requirements.
Need for international search information.
Speed.
Licensing plans.
Fundraising.
Product development.
Whether important target markets participate in the PCT.
For some applicants, direct filing can be efficient.
For others, the additional time and centralized international search provided by the PCT can be valuable.
18. Does the PCT Reduce the Cost of International Patents?
The PCT can postpone and consolidate certain early filing expenses.
It does not make international patent protection inexpensive.
During the international phase, the applicant can avoid immediately filing separate patent applications in every possible PCT market.
But substantial expenses can arise later if the applicant enters multiple national phases.
Potential later costs may include:
National filing fees.
Regional filing fees.
Translations.
Foreign associate fees.
Patent prosecution.
Examination fees.
Claim fees.
Grant fees.
Validation requirements.
Annuities.
Maintenance fees.
There is no reliable universal total cost for a PCT application and international patent portfolio.
PCT government costs themselves can include:
Receiving-office transmittal fees.
International filing fees.
International search fees.
Additional-page fees.
Optional preliminary-examination fees.
Fees can vary based on filing circumstances and the International Searching Authority used.
International patent budgeting should therefore distinguish between:
The cost of the PCT international phase
and
The later cost of national and regional patent prosecution.
19. Can a PCT Application Cover Taiwan and Other Non-PCT Countries?
No.
A PCT application cannot create a PCT filing effect in a jurisdiction that is not a PCT Contracting State.
For example, Taiwan is not currently a PCT Contracting State.
An applicant seeking patent protection in Taiwan must therefore consider a separate direct filing under the applicable Taiwanese patent and priority rules.
This distinction is important because filing a PCT application does not preserve every possible global market.
An international patent strategy should separately identify:
PCT countries.
Non-PCT jurisdictions.
Regional patent systems.
Direct-filing deadlines.
Priority requirements.
Foreign-filing restrictions.
Where important non-PCT jurisdictions are involved, coordination with appropriate foreign patent counsel may be necessary before the applicable deadline.
20. Can You File a PCT Application for a Design Patent?
The PCT is used for patent protection involving inventions.
It is not the international filing system for U.S.-style design patents directed to ornamental appearance.
International protection for industrial designs uses different national and international systems.
One important international system is WIPO’s Hague System for the International Registration of Industrial Designs.
The two systems should therefore be distinguished.
PCT: Patent protection for inventions.
Hague System: International industrial design protection.
A product containing both functional and ornamental innovation may therefore require separate international strategies.
Learn About Design Patents
21. How Can Cohn Legal Help With PCT Patent Applications?
Cohn Legal, PLLC assists inventors, startups, technology companies, manufacturers, and other businesses with PCT filings and international patent strategy.
Representation can begin by reviewing:
The invention.
Prior U.S. patent applications.
Provisional applications.
Priority dates.
Patentability search results.
Public disclosures.
Upcoming deadlines.
Commercial markets.
Competitors.
Manufacturing locations.
Potential licensees.
International business plans.
Patent budget.
Cohn Legal can assist with preparing and filing PCT applications, including:
Technical disclosure.
Patent claims.
Drawings.
Priority claims.
Required filing documentation.
Cohn Legal can also assist with:
PCT filing strategy.
Provisional-to-PCT strategy.
Utility-application-to-PCT filing.
Priority analysis.
Receiving-office issues.
International Searching Authority selection where alternatives are available.
International Search Report review.
Written Opinion analysis.
PCT claim amendments.
International preliminary examination strategy.
International publication issues.
National-phase planning.
U.S. national-stage entry.
Foreign filing deadlines.
Coordination with foreign patent counsel.
International patent portfolio strategy.
As national-phase deadlines approach, counsel can help identify which jurisdictions remain commercially important enough to justify continued investment.
The objective of the PCT is not to obtain a mythical worldwide patent.
It is to preserve international patent options while giving the applicant additional time and patentability information before committing to extensive country-by-country prosecution.
Discuss International Patent Protection
Speak With a Patent Attorney
FAQ
PCT Patent Application Frequently Asked Questions
What does PCT stand for?
PCT stands for Patent Cooperation Treaty.
The international patent system is administered by WIPO.
What is a PCT application?
A PCT application is an international patent application that allows a qualifying applicant to begin seeking patent protection across participating jurisdictions through a centralized filing process.
It does not create a worldwide patent.
Is a PCT patent an international patent?
No.
There is no single patent granted by WIPO through the PCT.
Actual patents are ultimately granted by national or regional patent offices.
How many countries are in the PCT?
As of September 2026, there are 159 PCT Contracting States.
Treaty membership should be confirmed when filing because it can change.
Does a PCT application cover every country in the world?
No.
The PCT covers Contracting States and available regional systems but does not include every country or territory.
Important non-PCT jurisdictions require separate filing analysis.
Do I choose the countries when I file the PCT application?
Generally, no.
Under the current system, filing the PCT request ordinarily designates all Contracting States bound by the Treaty on the international filing date.
The applicant generally chooses later which jurisdictions to pursue through national or regional phase entry.
Who can file a PCT application?
At least one applicant generally must be a national or resident of a PCT Contracting State.
Can a U.S. applicant file a PCT application through the USPTO?
Yes.
The USPTO can act as a competent PCT Receiving Office for qualifying U.S. nationals and residents.
Can a PCT application be filed directly with WIPO?
Potentially.
WIPO’s International Bureau can act as a receiving office for qualifying applicants, subject to nationality, residence, national-security, foreign-filing, and other requirements.
Can I file a PCT application after a U.S. provisional application?
Yes.
A common strategy is to file the PCT application within the 12-month priority period and claim priority to the provisional application.
The provisional must adequately support the subject matter for which its earlier filing date is claimed.
Does the PCT application have to be filed within 12 months?
If the applicant wants to claim ordinary priority to an earlier patent filing, the normal priority period for an invention is generally 12 months.
Limited restoration procedures may exist in qualifying circumstances.
Can a PCT application be my first patent filing?
Potentially, yes.
A PCT application can serve as the first patent filing if the applicant satisfies the applicable requirements.
Does a PCT application require patent claims?
Yes.
Unlike a U.S. provisional application, a PCT international application must contain one or more patent claims.
What does a PCT application contain?
A PCT application generally contains:
A request.
Description.
One or more claims.
Drawings where required.
An abstract.
Is a PCT application the same as a provisional patent application?
No.
A provisional application is a U.S. priority filing that does not require formal claims and is not subjected to the PCT international search process.
A PCT application is a substantive international patent application containing claims.
Does the PCT examiner grant the patent?
No.
International authorities provide searching and preliminary patentability analysis.
Final patent-grant decisions are made by national and regional patent offices.
What is an International Searching Authority?
An International Searching Authority, or ISA, is an authorized patent office or organization that conducts the PCT prior-art search and prepares the International Search Report and written opinion.
What is an International Search Report?
The ISR identifies prior-art references considered relevant to the patent claims.
It can help the applicant evaluate the application before national-phase filing decisions are made.
What is the PCT Written Opinion?
The Written Opinion provides a preliminary assessment of issues including novelty, inventive step, and industrial applicability.
It is not binding on national patent offices.
Does a favorable PCT search guarantee foreign patents?
No.
Each national or regional patent office ultimately applies its own law and examination procedures.
What happens if the PCT search is unfavorable?
The applicant can evaluate the cited prior art and determine whether to:
Amend claims where permitted.
Request international preliminary examination.
Proceed into selected national phases.
Change filing strategy.
Reconsider particular jurisdictions.
An unfavorable international opinion does not itself cancel the application.
Is a PCT application published?
Generally, yes.
WIPO ordinarily publishes the application shortly after 18 months from the priority date.
Where are PCT applications published?
Published international applications are made available through WIPO’s PATENTSCOPE system.
What is Chapter II of the PCT?
Chapter II provides an optional international preliminary examination procedure.
It can provide additional patentability analysis and consideration of qualifying amendments before national-phase entry.
What is national-phase entry?
National-phase entry occurs when the applicant begins pursuing the PCT application before selected national or regional patent offices.
Each office has its own applicable fees, forms, translations, examination procedures, and other requirements.
When is the PCT national-phase deadline?
For many jurisdictions, national-phase entry is due around 30 months from the priority date.
Some jurisdictions use 31 months or other specialized rules.
Each target jurisdiction should be confirmed individually.
Does the PCT give me 30 months after I file the PCT application?
Not necessarily.
The deadline is generally measured from the priority date, not simply from the PCT filing date.
If a provisional application was filed at month 0 and the PCT application at month 12, a 30-month national-phase deadline would generally arrive approximately 18 months after the PCT filing.
Does a PCT application extend my provisional application?
No.
The provisional application follows its own U.S. rules.
The PCT application is a new international filing that can claim priority to the provisional application when the applicable requirements are satisfied.
Can I enter national phase before month 30?
Yes.
An applicant generally does not need to wait until the national-phase deadline before proceeding in a selected jurisdiction.
Does a PCT application save money?
It can postpone and consolidate certain early expenses.
It does not eliminate the substantial country-specific filing, translation, prosecution, and maintenance costs that may arise later.
How much does a PCT application cost?
There is no single universal total.
Government fees may include:
Receiving-office fees.
International filing fees.
International search fees.
Additional-page fees.
Optional examination fees.
Current amounts depend on the filing circumstances and should be confirmed when the application is prepared.
Is Taiwan part of the PCT?
No.
A PCT application does not preserve a PCT national-phase route into Taiwan.
A separate filing strategy is required.
Are European countries available through the PCT?
Many are.
The PCT can provide access to European regional patent proceedings through the European Patent Office for participating states.
The appropriate route depends on the countries where protection is sought.
Can I obtain a U.S. patent through a PCT application?
Yes.
A PCT application designating the United States may later proceed into the U.S. national stage when the applicable requirements are satisfied.
Can I file a PCT application for a design patent?
No, not as the international route for ornamental design protection.
International industrial designs are addressed through separate systems, including the Hague System.
Does a PCT application give me worldwide patent rights?
No.
The PCT filing itself does not create enforceable worldwide patent rights.
Patent rights ultimately arise under national or regional law.
Can I decide not to enter any countries after filing the PCT?
Yes.
The applicant is not required to pursue every designated jurisdiction.
If the commercial value no longer justifies additional investment, the applicant may decide not to incur national-phase expenses.
What happens if I miss a national-phase deadline?
The consequences depend on the particular jurisdiction.
Some patent offices may provide limited restoration or reinstatement procedures, while others may provide different relief or no relief.
National-phase deadlines should therefore be treated as critical and calendared separately for every intended jurisdiction.
Preserve International Patent Options Before Committing to Country-by-Country Filing
The Patent Cooperation Treaty can provide inventors and businesses with additional time to determine where foreign patent protection is commercially justified.
A PCT application does not create an international patent.
It can, however:
Preserve options across participating jurisdictions.
Provide an international prior-art search.
Provide preliminary patentability information.
Postpone many country-specific filing expenses.
Allow additional time for commercial planning.
The system can be especially valuable when an applicant knows international protection may matter but is not yet ready to commit substantial resources to every possible market.
Cohn Legal assists inventors and companies with provisional-to-PCT strategy, PCT international applications, priority claims, international search results, national-phase planning, U.S. national-stage applications, and coordination with foreign patent counsel.
