The International Phase of the Patent Cooperation Treaty (PCT) begins once an international application (PCT Application) is filed at a Receiving Office. The PCT Application remains in the international Phase for 18 or 19 months. During this time, the PCT Application can enter either Chapter 1 or Chapter 2 routes (see below). By default, all PCT Applications follow Chapter 1. Optionally, a Chapter II demand can be made for the PCT Application to go through Chapter II.
The International Phase gives you:
- worldwide patent pending status,
- time to test market foreign markets, and
- a procedure to improve the likelihood of getting a patent.

What is the difference between Chapter I and Chapter II of the International Phase of the PCT?
The primary difference between Chapter I and Chapter II of the International Phase of the PCT is the level of interaction you have with the examiner.
Under Chapter 1 of the PCT, the International Search Authority examines the claims of the PCT Application and issues a Written Opinion. The Written Opinion lets you know whether the claims meet the requirement of novelty, inventive step (nonobviousness), and industrial applicability.
In response, you can file one set of amendments to the claims in the PCT Application. These amendments can address the rejections made by the examiner.
Under Chapter II of the PCT, you can have more than one opportunity to amend your claims with the goal of having a written opinion that states that the amended claims do meet the requirements of novelty, inventive step, and industrial applicability.
Which countries is worldwide patent pending status established?
Over 150 countries have signed the Patent Cooperation Treaty (PCT). As such, by filing a single PCT Application, your invention establishes patent pending status worldwide.
To maintain patent pending status in a foreign country, a national phase application has to be filed within 20, 30, or 31 months from the filing of the earliest priority application.
Two Letter Country Code | Country | Time Limit |
---|---|---|
AE | United Arab Emirates | 30 |
AG | Antigua and Barbuda | 30 |
AL | Albania | 31 |
AM | Armenia | 31 |
AO | Angola | 30 |
AP | African Regional Intellectual Property Organization | 31 |
AT | Austria | 30 |
AU | Australia | 31 |
AZ | Azerbaijan | 30 |
BA | Bosnia and Herzegovina | 34 |
BB | Barbados | 30 |
BG | Bulgaria | 31 |
BH | Bahrain | 30 |
BN | Brunei Darussalam | 30 |
BR | Brazil | 30 |
BW | Botswana | 31 |
BY | Belarus | 31 |
CH | Switzerland | 30 |
CZ | Czechia | 31 |
DE | Germany | 30 |
DJ | Djibouti | 30 |
DK | Denmark | 31 |
DM | Dominica | 30 |
EE | Estonia | 31 |
EP | European Patent Organisation | 31 |
ES | Spain | 30 |
FI | Finland | 31 |
GB | United Kingdom | 31 |
GD | Grenada | 30 |
GH | Ghana | 30 |
GM | Gambia | 30 |
HN | Honduras | 30 |
HR | Croatia | 31 |
HU | Hungary | 31 |
IR | Iran (Islamic Republic of) | 30 |
IS | Iceland | 31 |
IT | Italy | 30 |
JM | Jamaica | 30 |
JO | Jordan | 30 |
KE | Kenya | 30 |
KG | Kyrgyzstan | 31 |
KH | Cambodia | 30 |
KN | Saint Kitts and Nevis | 30 |
KW | Kuwait | 30 |
KZ | Kazakhstan | 31 |
LC | Saint Lucia | 30 |
LR | Liberia | 30 |
LS | Lesotho | 30 |
LU | Luxembourg | 20 |
LY | Libya | 30 |
MD | Republic of Moldova | 31 |
ME | Montenegro | 30 |
MK | North Macedonia | 31 |
MW | Malawi | 30 |
MZ | Mozambique | 31 |
NA | Namibia | 31 |
NO | Norway | 31 |
OA | African Intellectual Property Organization | 30 |
PA | Panama | 30 |
PL | Poland | 30 |
PT | Portugal | 30 |
QA | Qatar | 30 |
RO | Romania | 30 |
RS | Serbia | 30 |
RU | Russian Federation | 31 |
RW | Rwanda | 30 |
SA | Saudi Arabia | 30 |
SD | Sudan | 30 |
SE | Sweden | 31 |
SK | Slovakia | 31 |
SL | Sierra Leone | 31 |
ST | Sao Tome and Principe | 30 |
TJ | Tajikistan | 30 |
TM | Turkmenistan | 30 |
TR | Turkey | 30 |
UG | Uganda | 30 |
VC | Saint Vincent and the Grenadines | 31 |
WS | Samoa | 31 |
ZM | Zambia | 30 |
ZW | Zimbabwe | 30 |
How much time do you have to test market your product in foreign countries?
Applicants can test market their patent pending product in foreign countries while their PCT Application is in the International Phase.
PCT Applications remain in the International Phase for up to 20, 30, or 31 months from the earliest priority date. (See table above). In other words, you have 18 or 19 months from the date that you file the PCT Application to figure out which countries you want to file a patent application in.
Before the International Phase ends, Applicants can file a national phase application only in potentially profitable countries to continue patent pendency. Otherwise, patent pendency will be lost and a patent can’t be secured in the foreign country.
How to improve the likelihood of getting a patent during the International Phase of the PCT?
During the International Phase, the International Search Authority (ISA) performs a patent search and prepares a Written Opinion as to whether your invention appears to be patentable and on what issues it may lack novelty or inventive step.
In response, the claims of the PCT application can be amended to address any rejections identified in the Written Opinion. By addressing these rejections during the International Phase, Applicants can save money because they don’t have to address these issues individually when each national phase patent application is examined.
You can do this either under Chapter I or Chapter II. However, Chapter II has more flexibility in making amendments and trying to secure a positive written opinion on patentability.
What is USPTO's role during the International Phase of the PCT?
The USPTO may act as the Receiving Office and the International Search Authority (ISA) for the PCT Application. However, that is not mandatory. Typically, the U.S. will act as the Receiving Office while the International Searching Authority (ISA) is selected with a different contracting state (e.g., EPO or Russia) as the ISA.
Filing at the USPTO has its benefits. There are no surcharges required to file an international application with the USPTO. Any search or examination fees you pay to the USPTO are designated in U.S. dollars, rather than in Special Drawing Rights (SDRs). If certain procedures are followed, there are no translation requirements for applications filed in English and you may use an official translator for other language applications instead of a professional translator.