A PCT timeline tracks an international patent application from its earliest claimed priority date through search, publication, optional examination, and entry into selected national or regional patent offices.
Key Takeaways
- Calculate most PCT deadlines from the earliest valid priority date, not automatically from the PCT filing date.
- A priority-claiming PCT application generally must be filed within 12 months after the first application.
- International publication generally occurs shortly after 18 months from the priority date.
- National phase entry commonly occurs at 30 or 31 months, depending on the country or regional office.
- A PCT application does not create an international patent. Each selected office decides whether to grant national or regional rights.
- Missed-deadline relief may exist, but the requirements and availability vary by office.
PCT Timeline at a Glance
The following month-by-month outline uses the earliest valid claimed priority date as month zero. If the PCT application does not claim priority to an earlier application, its international filing date generally becomes the starting date. Actual calendar deadlines can also depend on weekends, holidays, document-transmittal dates, and the rules of the responsible office.
| Time From Priority Date | Typical PCT Milestone | Action for the Applicant |
|---|---|---|
| Month 0 | Earliest priority application is filed | Record the exact filing date and preserve the complete priority chain. |
| By month 12 | PCT filing deadline for claiming priority | File the international application with a competent receiving office and include the priority claim. |
| Usually around months 16 to 17 | International Search Report and written opinion | Review prior art, patentability findings, and possible claim amendments. |
| Promptly after month 18 | Publication of the PCT application | Assume the application will become publicly accessible unless it is withdrawn in time to prevent publication. |
| By the applicable month 22 deadline | Optional supplementary search or demand for preliminary examination | Decide whether added searching, amendments, or further patentability analysis justify the cost. |
| About month 28 | International preliminary reporting is generally completed | Use the available reports to finalize countries, budgets, translations, and claim strategy. |
| Month 30 or 31 | National or regional phase entry | File required documents, translations, fees, and local-agent appointments in each selected jurisdiction. |
The search report does not have one universal fixed month. Under the PCT framework, the International Searching Authority generally establishes it within three months after receiving the search copy or nine months from the priority date, whichever period expires later. This often places the report around month 16 when the PCT application was filed near the 12-month deadline.
How to Calculate PCT Filing Deadlines and Time Limits
Start with the earliest application whose priority is validly claimed. For example, if the first application was filed on April 10, month 12 ordinarily falls one year later, while months 18, 30, and 31 are counted from that same April 10 priority date. Do not add 30 months to the later PCT filing date when an earlier priority claim controls.
WIPO provides a free PCT Time Limit Calculator. Enter the priority date, select the relevant event, and review the calculated dates. Treat the result as a planning tool rather than a substitute for the rules of the receiving office, International Searching Authority, or national patent office. Confirm national phase dates through the current WIPO PCT Applicant's Guide.
- Identify every application in the priority chain.
- Determine which filing provides the earliest valid priority claim.
- Calculate the 12-month PCT filing date from that filing.
- Calculate publication and national phase dates from the same controlling date.
- Check each selected office for 30-month, 31-month, translation, fee, and holiday rules.
- Set internal reminders well before the official deadlines.
A calendar should also track deadlines triggered by receiving a document. For example, the deadline for filing a demand for international preliminary examination is generally the later of 22 months from the priority date or three months from transmittal of the search report and written opinion.
PCT 30- and 31-Month Countries
The PCT 30-month rule does not mean that every jurisdiction has the same deadline. It refers to the standard requirement in many contracting states to enter the national phase by 30 months from the earliest priority date. Other countries and regional offices provide 31 months. A few systems have special rules, extensions, reservations, or alternative regional routes.
This table gives common examples of PCT 30- and 31-month countries. It is not a complete list of PCT national phase deadlines by country. Always check the current WIPO national chapter and the relevant patent office before relying on a date.
| Standard Deadline | Country or Regional Office Examples | Planning Note |
|---|---|---|
| 30 months | United States, Canada, China, Japan, Brazil, Mexico, Israel, Singapore | Some offices offer limited late-entry or extension procedures, but applicants should not treat those procedures as ordinary filing periods. |
| 30 months | African Intellectual Property Organization, known as OAPI | A regional filing can cover eligible member states under the regional system. |
| 31 months | Australia, India, New Zealand, Republic of Korea, Russian Federation, United Kingdom | Local forms, translations, fees, or representative requirements may still need advance preparation. |
| 31 months | European Patent Office, African Regional Intellectual Property Organization, Eurasian Patent Organization | A regional phase can provide a route to protection in participating states, subject to later regional requirements. |
China generally uses a 30-month deadline, although its procedures may permit an additional period under specified conditions and with added requirements. Similar relief mechanisms elsewhere should never replace timely filing. Offices can change fees, forms, electronic filing systems, and reinstatement standards even when the basic month count remains the same.
If you plan to enter several jurisdictions, review the practical requirements by months 24 to 26. A PCT national phase application may require translations, national fees, powers of attorney, inventor information, assignments, or local counsel. Those tasks can take longer than calculating the deadline itself.
International Search, Publication, and Optional Examination
After filing, an International Searching Authority searches relevant patent and technical literature. It then issues an International Search Report and a written opinion addressing issues such as novelty, inventive step, and industrial applicability. These findings do not grant or deny a patent, but they can help you assess the likely strength and commercial value of the application.
You may amend the claims under PCT Article 19 after receiving the search report. The usual time limit is two months from transmittal of the report or 16 months from the priority date, whichever expires later. These amendments address the claims, not the description or drawings.
Publication of the PCT application normally occurs promptly after 18 months from the priority date. Publication generally makes the application, claims, description, drawings, and available search materials accessible to the public. If confidentiality remains commercially important, discuss publication timing before making disclosures, fundraising presentations, or product announcements.
Two optional procedures may follow. A supplementary international search lets another participating authority search for additional prior art, potentially including material in languages or collections not emphasized in the first search. The request generally must be filed before 22 months from the priority date.
International preliminary examination provides an additional, nonbinding patentability analysis and permits amendments under PCT Article 34. A demand is generally due by the later of 22 months from priority or three months after transmittal of the search report and written opinion. Neither optional procedure extends a national phase deadline automatically. Applicants should compare their potential value with projected PCT filing fees and international patent costs.
Preparing for National Phase Entry
The international phase ends when you move the application into selected national or regional offices. Each office then applies its own patent law, examination standards, fees, translation rules, and procedural requirements. A favorable international written opinion can help inform prosecution, but it does not require an office to grant a patent.
Begin by ranking countries according to actual business needs. Consider current and expected sales, manufacturing locations, licensing plans, competitors, enforceability, and the remaining commercial life of the technology. Filing everywhere may consume resources that could be used to prosecute stronger rights in core markets.
- Confirm the controlling priority date and each office's deadline.
- Choose between available national and regional filing routes.
- Obtain translation estimates and allow time for technical review.
- Confirm applicant ownership and record assignments when required.
- Budget government fees, translation charges, and local counsel costs.
- Decide whether claims should be amended for particular jurisdictions.
- Send final instructions before local filing cutoffs.
The PCT postpones many country-level expenses, but it does not eliminate them. National phase entry often concentrates several costs into a short period. Compare those expenses against the invention's expected value and the duration of potential patent rights. A broader explanation of patent duration appears in this guide to patent time limits.
If the national phase deadline is approaching, the priority chain is unclear, or you need to assess possible deadline relief, you can post your legal need on UpCounsel's marketplace. A patent attorney can validate the controlling priority date, calculate jurisdiction-specific deadlines, prepare entry documents, and coordinate with foreign patent counsel. Responses typically arrive within a day, helping you identify urgent filings without relying only on a general-purpose calculator.
What to Do About a Missed or Uncertain PCT Deadline
Act immediately if a PCT deadline may have passed. The available response depends on which deadline was missed, the reason for the delay, the receiving or designated office involved, and how much time has elapsed. Continuing to wait can eliminate a form of relief that was initially available.
Missing the 12-month priority period may prevent the PCT application from receiving the earlier application's priority date. PCT procedures permit requests to restore priority in certain circumstances, but time limits, standards, and the effect of restoration can vary. Some offices apply an unintentional standard, a due-care standard, or both. A restoration decision during the international phase also may not bind every national office.
Missing national phase entry can cause the international application to lose effect in that jurisdiction. Some offices provide reinstatement, restoration, extension, or late-entry procedures. These may require a petition, explanation, evidence, additional fee, or proof that the delay was unintentional or occurred despite due care. Other offices may offer narrower relief or none for the particular facts.
Preserve filing confirmations, docket reports, correspondence, payment records, and evidence explaining the delay. Do not assume that a general patent extension will apply to a PCT national phase deadline. The rules discussed in this overview of a patent extension of time illustrate why the type of deadline and responsible office matter.
When the date is uncertain, calculate both the earliest plausible deadline and any later alternative. Work toward the earliest date while confirming the priority claim, office closures, time-zone rules, and national requirements.
What a PCT Application Does and Does Not Do
A PCT application creates a coordinated filing and information-gathering process across PCT contracting states. It lets you begin with one international application instead of immediately preparing separate applications for every intended country. It also provides time to receive search results, investigate markets, seek financing, and decide where national patent protection is commercially justified.
The PCT does not create a worldwide patent. WIPO administers the international system, but it does not grant a patent that automatically applies in every member country. Patent rights arise only after national or regional offices examine the application and grant protection under their own laws.
The process has two broad phases. During the international phase, the application undergoes formal processing, search, publication, and any selected optional procedures. During the national phase, chosen offices handle substantive examination, local objections, amendments, and grant or refusal.
The extra planning period can be valuable, but it should not be mistaken for a guarantee of more time in every situation. Direct national filing under the Paris Convention may suit an applicant who already knows where protection is needed. A PCT filing may better suit an applicant who wants to defer major country-selection decisions while receiving an international search.
Use the period before national phase entry to test assumptions rather than merely postpone them. Review the search report, update revenue forecasts, identify potential licensees, assess competitors, and set country-specific budgets. By month 30 or 31, you should have both a legal filing plan and a business reason for each selected jurisdiction.
Frequently Asked Questions
What is the PCT 30-month rule?
The PCT 30-month rule generally requires an applicant to enter the national phase within 30 months from the earliest valid priority date. It is not universal because some national and regional offices use 31 months or apply special provisions. The deadline concerns entry into each selected office, not the duration of the resulting patent.
What are the steps of the PCT process?
The main PCT steps are international filing, formal review, international search, written opinion, publication, optional supplementary search or preliminary examination, and national phase entry. The applicant then prosecutes the application separately before each selected national or regional office. Local examination can produce different results even when every office begins with the same published application.
Can a PCT application claim priority to an earlier PCT application?
Yes, a later PCT application can claim priority to an earlier PCT application if the priority claim satisfies the applicable requirements. The earlier application must support the claimed subject matter, and the later application generally must be filed within the 12-month priority period. Ownership, applicant rights, and any intervening applications should be reviewed carefully.
How long does a PCT application take?
A PCT application typically remains in the international phase until national phase entry around 30 or 31 months from the priority date. That period does not measure the time to obtain a granted patent. National or regional examination begins or continues afterward, and its duration depends on the chosen office, technology, objections, and applicant responses.
Does filing a PCT application guarantee patent protection?
No, filing a PCT application does not guarantee patent protection in any country. It preserves a route to seek protection in designated contracting states and provides centralized search and publication procedures. Each national or regional office independently evaluates patentability and compliance with its domestic law before granting enforceable rights.
