MPEP § 1842 — Basic Flow Under the PCT (Annotated Rules)

§1842 Basic Flow Under the PCT

USPTO MPEP version: BlueIron's Update: 2025-12-31

This page consolidates and annotates all enforceable requirements under MPEP § 1842, including statutory authority, regulatory rules, examiner guidance, and practice notes. It is provided as guidance, with links to the ground truth sources. This is information only, it is not legal advice.

Basic Flow Under the PCT

This section addresses Basic Flow Under the PCT. Contains: 3 requirements, 3 permissions, and 3 other statements.

Key Rules

Topic

Article 34 Amendments

5 rules
StatutoryInformativeAlways
[mpep-1842-bee755537d0c56a95bc0b0a6]
Optional International Preliminary Examination
Note:
A demand for international preliminary examination can be filed up to 22 months from the priority date, but is not mandatory.

International preliminary examination is optional. A demand for international preliminary examination must be filed prior to the expiration of whichever of the following periods expires later: (A) three months from the date of transmittal to the applicant of the international search report and the written opinion; or (B) 22 months from the priority date. Otherwise the demand shall be considered as if it had not been submitted and the International Preliminary Examining Authority shall so declare. See PCT Rule 54. In order to take advantage of a national phase entry time limit of at least 30 months from the priority date in relation to all States designated in the international application, it may be necessary to file a demand before the expiration of 19 months from the priority date. See subsection VII.A., below.

Jump to MPEP SourceArticle 34 AmendmentsInternational Preliminary Examination (Chapter II)National Stage Examination
StatutoryRequiredAlways
[mpep-1842-4dbeaa8e8f649e768c0def2c]
Demand for International Preliminary Examination Must Be Filed Before Later Expiration Date
Note:
A demand for international preliminary examination must be filed before the later of three months after receiving the international search report and written opinion or 22 months from the priority date.

International preliminary examination is optional. A demand for international preliminary examination must be filed prior to the expiration of whichever of the following periods expires later: (A) three months from the date of transmittal to the applicant of the international search report and the written opinion; or (B) 22 months from the priority date. Otherwise the demand shall be considered as if it had not been submitted and the International Preliminary Examining Authority shall so declare. See PCT Rule 54. In order to take advantage of a national phase entry time limit of at least 30 months from the priority date in relation to all States designated in the international application, it may be necessary to file a demand before the expiration of 19 months from the priority date. See subsection VII.A., below.

Jump to MPEP SourceArticle 34 AmendmentsDemand for Preliminary ExaminationInternational Searching Authority (ISA)
StatutoryRequiredAlways
[mpep-1842-f3ab86a271af8167c3293e90]
Demand for International Preliminary Examination Required Before Expiration of Periods
Note:
A demand for international preliminary examination must be filed before the expiration of certain periods, otherwise it will not be considered submitted.

International preliminary examination is optional. A demand for international preliminary examination must be filed prior to the expiration of whichever of the following periods expires later: (A) three months from the date of transmittal to the applicant of the international search report and the written opinion; or (B) 22 months from the priority date. Otherwise the demand shall be considered as if it had not been submitted and the International Preliminary Examining Authority shall so declare. See PCT Rule 54. In order to take advantage of a national phase entry time limit of at least 30 months from the priority date in relation to all States designated in the international application, it may be necessary to file a demand before the expiration of 19 months from the priority date. See subsection VII.A., below.

Jump to MPEP SourceArticle 34 AmendmentsDemand for Preliminary ExaminationInternational Preliminary Examining Authority (IPEA)
StatutoryInformativeAlways
[mpep-1842-03b3a8a461be0621dc886a19]
National Stage Requirements Due Within 30 Months of Priority Date
Note:
The national stage requirements must be met by the expiration of 30 months from the priority date if no demand has been filed, effective April 1, 2002.

PCT Article 22(1) was amended, effective April 1, 2002, to specify that the national stage requirements are due not later than at the expiration of 30 months from the priority date if no demand has been filed. Prior to April 1, 2002, PCT Article 22(1) specified that these requirements were due not later than at the expiration of 20 months from the priority date. See www.wipo.int/pct/en/texts/time_limits.html for a list of the Contracting States that have not yet changed their national laws to adopt the 30 month period now set forth in PCT Article 22(1). (At the time of publication of this Chapter, only two countries have not adopted Article 22(1) as amended: Luxembourg (LU) and the United Republic of Tanzania (TZ). It is noted that Luxembourg is included in the regional designation “EPO” and that the United Republic of Tanzania is included in the regional designation “ARIPO.”)

Jump to MPEP SourceArticle 34 AmendmentsDemand for Preliminary ExaminationNational Stage Entry Requirements
StatutoryInformativeAlways
[mpep-1842-f81c83681de51dcd8eb37189]
Provisions of Article 39 Apply Instead of Article 22
Note:
If the election of a Contracting State is made before the 19th month from the priority date, Article 39's provisions take precedence over those in Article 22.

If the election of a Contracting State has been effected by filing a demand prior to the expiration of the 19th month from the priority date, the provisions of Article 39 apply rather than the provisions of Article 22. The deadline for filing the national stage requirements under PCT Article 39(a) is 30 months from the priority date, but any national law may fix time limits which expire later than the time limit provided in PCT Article 39(a). See PCT Article 39(b) and the list of time limits found on WIPO’s website at www.wipo.int/pct/en/texts/ time_limits.html.

Jump to MPEP SourceArticle 34 AmendmentsDemand for Preliminary ExaminationNational Stage Entry Timing (30 Months)
Topic

Patent Cooperation Treaty

3 rules
StatutoryInformativeAlways
[mpep-1842-dad2ac2762c8694a153deb3e]
Time Limits Measured from Priority Date
Note:
Time limits under the PCT are calculated from the priority date of the application, which is defined in PCT Article 2(xi).

Time limits under the PCT are measured from the “priority date” of the application. The priority date for the purposes of computing time limits is defined in PCT Article 2(xi). Where an international application does not contain any priority claim under PCT Article 8, the international filing date is considered to be the priority date.

Jump to MPEP SourcePatent Cooperation TreatyInternational Filing DatePCT International Application Filing
StatutoryInformativeAlways
[mpep-1842-663cba5e89edf1d7a0bf3cc8]
Priority Date for Time Limits Under PCT
Note:
The priority date used to measure time limits under the Patent Cooperation Treaty is defined in Article 2(xi).

Time limits under the PCT are measured from the “priority date” of the application. The priority date for the purposes of computing time limits is defined in PCT Article 2(xi). Where an international application does not contain any priority claim under PCT Article 8, the international filing date is considered to be the priority date.

Jump to MPEP SourcePatent Cooperation TreatyInternational Filing DatePCT International Application Filing
StatutoryInformativeAlways
[mpep-1842-8d09627d9bfa99804cd170b6]
Deadline for Filing National Stage Requirements Under PCT
Note:
The deadline for filing national stage requirements under the Patent Cooperation Treaty is 30 months from the priority date, unless a later date is set by national law.

If the election of a Contracting State has been effected by filing a demand prior to the expiration of the 19th month from the priority date, the provisions of Article 39 apply rather than the provisions of Article 22. The deadline for filing the national stage requirements under PCT Article 39(a) is 30 months from the priority date, but any national law may fix time limits which expire later than the time limit provided in PCT Article 39(a). See PCT Article 39(b) and the list of time limits found on WIPO’s website at www.wipo.int/pct/en/texts/ time_limits.html.

Jump to MPEP SourcePatent Cooperation TreatyNationals and ResidentsReceiving Office (RO/US)
Topic

Nationals and Residents

3 rules
StatutoryPermittedAlways
[mpep-1842-d4bd8611bc8f1b8b8675e710]
Demand Before 19 Months for National Phase Entry
Note:
To enter the national phase within 30 months of the priority date, a demand must be filed by 19 months from the priority date.

International preliminary examination is optional. A demand for international preliminary examination must be filed prior to the expiration of whichever of the following periods expires later: (A) three months from the date of transmittal to the applicant of the international search report and the written opinion; or (B) 22 months from the priority date. Otherwise the demand shall be considered as if it had not been submitted and the International Preliminary Examining Authority shall so declare. See PCT Rule 54. In order to take advantage of a national phase entry time limit of at least 30 months from the priority date in relation to all States designated in the international application, it may be necessary to file a demand before the expiration of 19 months from the priority date. See subsection VII.A., below.

Jump to MPEP SourceNationals and ResidentsReceiving Office (RO/US)Article 34 Amendments
StatutoryInformativeAlways
[mpep-1842-3bd87cce9486b59bd6201b2f]
Demand for International Preliminary Examination Required Before Priority Date + 22 Months
Note:
A demand for international preliminary examination must be filed before the later of three months after receiving the international search report or 22 months from the priority date, otherwise it will not be considered.

International preliminary examination is optional. A demand for international preliminary examination must be filed prior to the expiration of whichever of the following periods expires later: (A) three months from the date of transmittal to the applicant of the international search report and the written opinion; or (B) 22 months from the priority date. Otherwise the demand shall be considered as if it had not been submitted and the International Preliminary Examining Authority shall so declare. See PCT Rule 54. In order to take advantage of a national phase entry time limit of at least 30 months from the priority date in relation to all States designated in the international application, it may be necessary to file a demand before the expiration of 19 months from the priority date. See subsection VII.A., below.

Jump to MPEP SourceNationals and ResidentsReceiving Office (RO/US)Article 34 Amendments
StatutoryPermittedAlways
[mpep-1842-6e407d4e86012698c4949c1e]
Deadline for Filing National Stage Requirements Under PCT Article 39(a)
Note:
The deadline to file national stage requirements is 30 months from the priority date, but may be extended by national laws.

If the election of a Contracting State has been effected by filing a demand prior to the expiration of the 19th month from the priority date, the provisions of Article 39 apply rather than the provisions of Article 22. The deadline for filing the national stage requirements under PCT Article 39(a) is 30 months from the priority date, but any national law may fix time limits which expire later than the time limit provided in PCT Article 39(a). See PCT Article 39(b) and the list of time limits found on WIPO’s website at www.wipo.int/pct/en/texts/ time_limits.html.

Jump to MPEP SourceNationals and ResidentsReceiving Office (RO/US)National Stage Entry Requirements
Topic

International Filing Date

2 rules
StatutoryInformativeAlways
[mpep-1842-c004d589f16f3b74e89bc27a]
International Filing Date as Priority Date
Note:
When an international application does not claim priority, the filing date becomes the priority date for PCT time limit calculations.

Time limits under the PCT are measured from the “priority date” of the application. The priority date for the purposes of computing time limits is defined in PCT Article 2(xi). Where an international application does not contain any priority claim under PCT Article 8, the international filing date is considered to be the priority date.

Jump to MPEP SourceInternational Filing DatePCT International Application FilingPatent Cooperation Treaty
StatutoryRequiredAlways
[mpep-1842-0c85c83207ac3cd6aa73fe4a]
Elements for Acceding International Filing Date
Note:
PCT Article 11 outlines the requirements needed for an international application to receive a filing date under the Patent Cooperation Treaty.

An international application under the Patent Cooperation Treaty is generally filed within 12 months after the filing of the first application directed to the same subject matter, so that priority may be claimed under PCT Article 8 and Article 4 of the Stockholm Act of the Paris Convention for the Protection of Industrial Property. PCT Article 11 specifies the elements required for an international application to be accorded an international filing date.

Jump to MPEP SourceInternational Filing DatePCT International Application FilingPatent Cooperation Treaty
Topic

International Searching Authority (ISA)

2 rules
StatutoryInformativeAlways
[mpep-1842-9a8a893d990ef263885a3b56]
Time Limit for ISA Search Report and Opinion
Note:
The International Searching Authority must establish the search report and written opinion within three months of receiving the search copy, or nine months from the priority date, whichever is later.

As provided in PCT Rule 42 and PCT Rule 43bis, the time limit for establishing the international search report (or a declaration that no international search report will be established) and written opinion is three months from the receipt of the search copy by the International Searching Authority, or nine months from the priority date, whichever time limit expires later.

Jump to MPEP SourceInternational Searching Authority (ISA)International Search ReportWritten Opinion of ISA
StatutoryPermittedAlways
[mpep-1842-a41e65dbb3abd67f679e903a]
Request for Supplementary ISA Search Before 22 Months
Note:
Applicants can request additional searches from a different ISA before the 22-month priority deadline.

As provided in PCT Rule 45bis, at any time prior to the expiration of 22 months from the priority date, the applicant can request one or more supplementary international searches each to be carried out by an International Searching Authority other than the International Searching Authority which carries out the main international search.

Jump to MPEP SourceInternational Searching Authority (ISA)Priority Claim in PCTRequest Content and Form
Topic

PCT International Application Filing

1 rules
StatutoryPermittedAlways
[mpep-1842-478fce0391a945832ef3428e]
PCT Filing Within 12 Months for Priority Claim
Note:
An international application under the Patent Cooperation Treaty must be filed within 12 months of the first application to claim priority under PCT Article 8 and Article 4 of the Stockholm Act.

An international application under the Patent Cooperation Treaty is generally filed within 12 months after the filing of the first application directed to the same subject matter, so that priority may be claimed under PCT Article 8 and Article 4 of the Stockholm Act of the Paris Convention for the Protection of Industrial Property. PCT Article 11 specifies the elements required for an international application to be accorded an international filing date.

Jump to MPEP SourcePCT International Application FilingPatent Cooperation TreatyInternational Filing Date
Topic

Article 19 Amendment Scope

1 rules
StatutoryRequiredAlways
[mpep-1842-1bdba4015ca23a0ad631807c]
International Application Must Be Published Promptly After 18 Months
Note:
The International Bureau must publish the international application promptly after 18 months from its priority date.

Under PCT Article 21, the international publication of the international application by the International Bureau shall be effected promptly after the expiration of 18 months from the priority date of that application.

Jump to MPEP SourceArticle 19 Amendment ScopePublication LanguagePublication Timing (18 Months)
Topic

Demand for Preliminary Examination

1 rules
StatutoryPermittedAlways
[mpep-1842-9b6c7bb06ec96a41ab817f93]
National Stage Time Limits Found on WIPO Website
Note:
The rule requires that a listing of all national and regional offices along with their corresponding time limits for entering the national stage following PCT Chapter I and II can be found on WIPO’s website.

A listing of all national and regional offices, and the corresponding time limits for entering the national stage following PCT Chapter I and PCT Chapter II, may be found on WIPO’s website at: www.wipo.int/pct/en/texts/time_limits.html.

Jump to MPEP SourceDemand for Preliminary ExaminationAmendments in National StageInternational Preliminary Examination (Chapter II)
Topic

National Stage Entry Requirements

1 rules
StatutoryInformativeAlways
[mpep-1842-f67b5ced3f491049028a3d4b]
National Stage Requirements Due by 30 Months
Note:
The national stage requirements must be met no later than 30 months from the priority date if no demand has been filed, effective April 1, 2002.

PCT Article 22(1) was amended, effective April 1, 2002, to specify that the national stage requirements are due not later than at the expiration of 30 months from the priority date if no demand has been filed. Prior to April 1, 2002, PCT Article 22(1) specified that these requirements were due not later than at the expiration of 20 months from the priority date. See www.wipo.int/pct/en/texts/time_limits.html for a list of the Contracting States that have not yet changed their national laws to adopt the 30 month period now set forth in PCT Article 22(1). (At the time of publication of this Chapter, only two countries have not adopted Article 22(1) as amended: Luxembourg (LU) and the United Republic of Tanzania (TZ). It is noted that Luxembourg is included in the regional designation “EPO” and that the United Republic of Tanzania is included in the regional designation “ARIPO.”)

Jump to MPEP SourceNational Stage Entry RequirementsNational Stage Entry Timing (30 Months)Publication Timing (18 Months)
Topic

Publication Language

1 rules
StatutoryInformativeAlways
[mpep-1842-e737ec9235130ffc60f77363]
Amended PCT Article 22(1) National Stage Requirements
Note:
The national stage requirements under the amended PCT Article 22(1) are due not later than 30 months from the priority date if no demand has been filed, with Luxembourg and Tanzania as exceptions.

PCT Article 22(1) was amended, effective April 1, 2002, to specify that the national stage requirements are due not later than at the expiration of 30 months from the priority date if no demand has been filed. Prior to April 1, 2002, PCT Article 22(1) specified that these requirements were due not later than at the expiration of 20 months from the priority date. See www.wipo.int/pct/en/texts/time_limits.html for a list of the Contracting States that have not yet changed their national laws to adopt the 30 month period now set forth in PCT Article 22(1). (At the time of publication of this Chapter, only two countries have not adopted Article 22(1) as amended: Luxembourg (LU) and the United Republic of Tanzania (TZ). It is noted that Luxembourg is included in the regional designation “EPO” and that the United Republic of Tanzania is included in the regional designation “ARIPO.”)

Jump to MPEP SourcePublication LanguageInternational PublicationArticle 34 Amendments

Citations

Primary topicCitation
International Filing Date
PCT International Application Filing
PCT Article 11
International Filing Date
Patent Cooperation Treaty
PCT Article 2(xi)
Article 19 Amendment ScopePCT Article 21
Article 34 Amendments
National Stage Entry Requirements
Publication Language
PCT Article 22(1)
Article 34 Amendments
Nationals and Residents
Patent Cooperation Treaty
PCT Article 39(b)
International Searching Authority (ISA)PCT Rule 42
International Searching Authority (ISA)PCT Rule 43bis
International Searching Authority (ISA)PCT Rule 45bis
Article 34 Amendments
Nationals and Residents
PCT Rule 54
International Filing Date
PCT International Application Filing
Patent Cooperation Treaty
PCT Article 8

Source Text from USPTO’s MPEP

This is an exact copy of the MPEP from the USPTO. It is here for your reference to see the section in context.

BlueIron Last Updated: 2025-12-31