Using PCT Chapter II Before National Phase Entry

Executive Summary: Chapter II of the Patent Cooperation Treaty offers applicants an optional opportunity to address examination objections, amend the application, and obtain an international preliminary examination report before national phase entry. Its greatest value arises when that process preserves commercially meaningful claims and produces identifiable benefits in the jurisdictions where protection is sought. A favorable report remains nonbinding: it does not guarantee a patent, produce uniform fee savings, or generally extend national-entry deadlines. This article examines the demand and examination process, associated costs, and practical effects in the United States, Europe, China, South Korea, and Japan, distinguishing benefits tied to favorable findings from those dependent on which authority performed the work. It also explains restrictions on selecting an examining authority, differences in examiner interaction, and the requirements for accelerated examination. An existing favorable written opinion may already support acceleration, while further examination can change that position where the applicable program requires the latest PCT work product. The decision to request Chapter II should therefore weigh the expected improvement in useful claim scope and national prosecution against additional expense, procedural constraints, and benefits already available without further international examination.

Introduction

An applicant deciding whether to request Chapter II examination under the Patent Cooperation Treaty should begin with the claims it expects to pursue. The procedure can provide an opportunity to answer international examination objections, amend the application, and obtain a report useful in later national proceedings. Its value depends on whether the resulting claims remain commercially important and whether the intended patent offices offer meaningful procedural or financial benefits. Chapter II is optional, and its patentability assessment remains preliminary and nonbinding. (PCT art. 31(1); PCT art. 33(1).)

The decision also requires a distinction between benefits attributable to a favorable result and benefits attributable to the identity of the authority performing the work. A positive report can support accelerated examination, but certain national fee reductions are available because a particular office conducted the international search or examination, regardless of its conclusions. An applicant that already has a favorable international written opinion may therefore have much of the procedural benefit without incurring the additional cost of Chapter II.

I The decision after receiving the ISR

 

The International Search Report (ISR) and the Written Opinion of the International Searching Authority (WO/ISA) perform different functions. The ISR identifies relevant documents located during the international search. The written opinion addresses whether the claims appear to satisfy novelty, inventive step, and industrial applicability, and whether other requirements examined by the authority have been met. The opinion, rather than the mere existence of cited references, supplies the starting point for evaluating the need for a substantive response. (PCT R. 43.5; PCT R. 43bis.1.)

If an international preliminary examination report is not established, the International Bureau generally issues an International Preliminary Report on Patentability under Chapter I based on the WO/ISA. Chapter II examination produces the report commonly called the IPER, which bears the title International Preliminary Report on Patentability under Chapter II. The terminology identifies different procedural routes; a Chapter I report can contain favorable findings, and a Chapter II report can remain unfavorable. (PCT R. 44bis.1; PCT R. 70.15(b).)

An applicant need not request Chapter II merely because the WO/ISA is negative. It can pursue examination in the selected national or regional offices. Another option is to amend the claims under Article 19, ordinarily within the later of two months after transmission of the ISR or sixteen months from the priority date. Article 19 provides one opportunity to amend the claims before the International Bureau; it does not itself obtain Chapter II examination of those amendments. Chapter II supplies a separate procedure for presenting arguments and amendments to an International Preliminary Examining Authority (IPEA). (PCT art. 19; PCT R. 46.1; PCT art. 31.)

II What Chapter II adds

 

Chapter II permits examination of the claimed invention against the PCT criteria for novelty, inventive step, and industrial applicability. Those criteria guide the international assessment; individual states may apply additional or different criteria when deciding national patentability. An applicant should therefore view the procedure as an opportunity to develop a stronger examination record before national entry, while recognizing that local eligibility, disclosure, and other requirements still apply. (PCT art. 33(1)–(5).)

Its amendment opportunity is broader than Article 19. Under Article 34, the applicant may amend the claims, description, and drawings without introducing subject matter beyond the disclosure in the application as filed. Amendments should identify their basis in that disclosure. An amendment cannot introduce an unsupported technical feature merely because it would overcome the cited art. Timing also matters: the IPEA need not consider amendments or arguments received after it has begun drawing up its opinion or report. Filing before the report issues does not necessarily ensure consideration. (PCT art. 34(2)(b); PCT R. 66.4bis, 66.8.)

The applicant also has a right to communicate with the IPEA and an opportunity to respond to its written opinion. This can be useful where the international analysis overlooks a limitation or misunderstands the operation of the claimed invention. The procedure is not an appeal from the ISA, however, and it does not promise an unlimited series of examination exchanges. A well-supported demand response should present the applicant’s substantive case promptly. (PCT art. 34(2)(a), (c)–(d); WIPO, International Search and Preliminary Examination Guidelines ¶¶ 19.23–19.24.)

III When the additional examination is worth pursuing

 

Chapter II is especially attractive when the applicant plans several important national filings and the objection is common to the claims it intends to pursue in those markets. An international response that explains a previously overlooked technical distinction may give national counsel a useful starting point. A supported amendment may also produce favorable findings that allow accelerated examination requests in multiple offices. These are potential efficiencies, rather than assurances that each national examiner will accept the same reasoning.

The strength of the contemplated amendment matters more than the prospect of obtaining a favorable label. A limitation directed to an essential product feature may preserve valuable protection while addressing the prior art. A limitation directed to an incidental implementation detail may instead leave competitors an easy route around the claim. The latter result can make an apparently successful Chapter II proceeding commercially disappointing.

The expected benefit should also be measured against what the applicant already has. PCT-PPH arrangements can accept favorable WO/ISA findings as well as favorable Chapter II work products. If the existing written opinion already supports acceleration for the claims the applicant wants, an additional examination may provide little incremental value for that purpose. Other considerations, including an authority-specific fee reduction, may still justify it. (JPO, PCT-PPH, Outline.)

Additional examination can also change the work product that must support a later acceleration request. Where the applicable PPH arrangement requires the latest PCT work product, an applicant should assess whether Chapter II could produce findings adverse to claims that were previously treated favorably. The claim-specific consequences are discussed in Section VIII. (IP5 Offices, IP5 Patent Prosecution Highway, Bases for a PPH Request.)

Direct national prosecution may be preferable where the principal dispute concerns a particular country’s law, the applicant intends to enter only a limited number of markets, or an acceptable international claim set would be too narrow. Chapter II should serve a defined prosecution objective, such as resolving an identifiable objection or obtaining useful findings for a planned acceleration request.

IV The demand and examination process

 

Chapter II is most useful when the applicant treats the demand as the beginning of a prepared substantive response. Counsel should identify the application text to be examined, explain why the claims overcome the search opinion, and leave time for any further exchange before the report is prepared. Merely filing the demand does not assure a new invitation to respond: the WO/ISA ordinarily already serves as the IPEA’s first written opinion. (See WIPO, International Search and Preliminary Examination Guidelines ¶¶ 3.19–3.21.)

Filing the demand with the competent authority

 

The demand deadline is the later of twenty-two months from the priority date or three months from transmittal to the applicant of the ISR, or the prescribed declaration that no ISR will be established, and the WO/ISA. The relevant date is transmittal, rather than the date counsel happens to review the documents. A demand submitted after the applicable deadline is treated as though it had not been submitted. Docketing only the twenty-two-month date can therefore overlook a later deadline when the search materials are transmitted late. (PCT R. 54bis.1.)

The applicant must select a competent IPEA, taking account of eligibility, the receiving office, any restrictions associated with the ISA that performed the search, and the languages the authority accepts. The demand identifies the application and applicant, contains the request for preliminary examination, and specifies relevant amendments. Filing it elects all designated states bound by Chapter II; counsel need not select those states individually in the demand. A translation may be necessary if the IPEA accepts neither the filing language nor the publication language. (PCT arts. 31(2), (3), (6); PCT R. 53.2, 53.7, 53.9; PCT R. 59.1; PCT R. 55.2.)

The EPO illustrates the importance of the search authority. It acts as IPEA only where the international search was performed by the EPO or another qualifying ISA located in and operating for an EPC contracting state. Accordingly, an applicant that used the USPTO as ISA cannot simply select the EPO for Chapter II to obtain the later European examination-fee reduction. (WIPO, PCT Applicant’s Guide, Annex E (EP), Restrictions on IPEA Competence, valid Sept. 17, 2026.)

Completing formalities and paying the fees

 

The demand and fee deadlines are separate. The handling and preliminary examination fees are generally due by the later of one month after submission of the demand or twenty-two months from priority. Special provisions apply to a demand forwarded to the competent IPEA and to an authority beginning examination together with the search. If payment is missing or insufficient, the IPEA invites payment within one month, with a late-payment fee where applicable. Failure to satisfy that invitation can result in the demand being treated as not submitted. (PCT R. 57.3; PCT R. 58.1(b); PCT R. 58bis.1–58bis.2.)

The IPEA also checks the demand for formal defects and, where the prescribed requirements are not met, invites correction within a period of at least one month. A timely correction generally preserves the original submission date if the demand as submitted identified the international application. If it did not, the correction date controls. These procedures should not be treated as a substitute for a complete and timely filing, particularly when identification of the application is deficient. (PCT R. 60.1(a)–(c).)

Defining the application to be examined

 

The demand should make clear whether examination is requested on the original application, on Article 19 claim amendments, or on amendments submitted under Article 34. If Article 19 amendments already exist, the statement concerning amendments indicates whether they should be considered or reversed by an Article 34 amendment. If Article 34 amendments accompany the demand, the statement identifies that fact. Clear identification of the operative text prevents the examiner from having to infer which of several claim sets the applicant intends to pursue. (PCT R. 53.9.)

An Article 34 claim amendment requires a complete replacement claim set, rather than only the individual claims being changed. Its accompanying letter identifies the changed or canceled claims, explains the differences, and indicates the basis for the amendments in the application as filed. Amendments to the description or drawings generally require replacement sheets and a corresponding explanation of the changes and their original support. Pinpoint references to the relevant passages and figures help the examiner assess an amendment without searching the entire disclosure for its basis. (PCT R. 46.5, as applied by PCT R. 66.8(c); WIPO, International Search and Preliminary Examination Guidelines ¶ 20.06.)

The substantive response should address the opinion claim by claim where the issues differ. It should explain the feature the reference fails to disclose, the reason a proposed combination does not establish the asserted lack of inventive step, or the effect of a supported amendment on the examiner’s analysis. Clarity and support observations also deserve attention because they can remain in a report even after the principal prior-art objection is resolved. A claim comparison and precise support citations can make that reasoning easier to assess; neither replaces the required amendment documents.

Starting examination and using the search opinion

 

Examination generally begins when the IPEA has the demand, the full required fees, and the prescribed search report or no-search declaration and written opinion. The applicant may expressly request postponement until the applicable demand deadline. The rules also address waiting for specified Article 19 amendments and for Article 34 amendments identified as accompanying the demand but not actually supplied. Counsel should not assume that an early demand leaves the examiner inactive until twenty-two months. (PCT R. 69.1.)

Because the WO/ISA ordinarily counts as the first IPEA opinion, the applicant should normally submit its principal arguments and amendments with the demand. Certain IPEAs have notified exceptions for opinions issued by specified other ISAs; the applicant must be notified when such an exception applies. Even then, the IPEA considers the ISA’s analysis in preparing its own opinion. The practical question is whether the record already contains the opinion to which counsel should respond, rather than whether the IPEA has issued a newly labeled communication. (PCT R. 66.1bis; WIPO, International Search and Preliminary Examination Guidelines ¶¶ 3.19–3.21.)

Reviewing the claims and conducting the additional search

 

The examiner considers the application text, amendments, arguments, and relevant cited documents. The IPEA normally also performs a top-up search for material that became available after the ISR was established, unless the search would serve no useful purpose. This can uncover earlier-filed, later-published applications or documents that were unavailable to the original searcher. The top-up search ordinarily remains within the scope of the original search, and no separate search report issues from it; relevant findings appear in the opinion or IPER. (WIPO, International Search and Preliminary Examination Guidelines ¶¶ 19.14–19.21.)

If the IPEA intends to raise objections based on prior art discovered in that search, the guidelines call for a further written opinion. Under the general PCT framework, an additional opinion on other unresolved objections is discretionary when the WO/ISA counted as the first opinion. A credible effort to answer the objections and sufficient remaining examination time can support another exchange, but counsel should not budget the response around a guaranteed second office action. (WIPO, International Search and Preliminary Examination Guidelines ¶¶ 19.23–19.24.)

Authority-specific practice may provide an additional opportunity to respond. Where the EPO acts as IPEA after serving as ISA, its 2026 Guidelines generally require further interaction before a negative IPER if the applicant timely submitted substantive arguments or amendments addressing the WO/ISA. A further written opinion is the usual form; a telephone consultation requested before that opinion may instead be followed by minutes, generally with a two-month reply period. The EPO does not grant personal interviews in this procedure. An exception permits a negative IPER without a further written opinion where lack of unity is the only remaining objection and all examined inventions were found novel and inventive. These provisions support a further response opportunity, without promising unlimited exchanges. (EPO PCT Guidelines C-IV, § 2.2 (2026); id. C-VII, § 1.)

Responding to opinions and communicating with the examiner

 

An IPEA written-opinion notification ordinarily sets a two-month reply period. The period must be reasonable, cannot be shorter than one month, and generally cannot exceed three months absent an extension; at least two months must be allowed if the ISR accompanies the notification. An extension may be granted if requested before expiration. The formal response goes directly to the IPEA. These rules do not create a universal two-month response period beginning with receipt of the original WO/ISA. (PCT R. 66.2(d)–(e), 66.3.)

An interview or telephone discussion can help identify whether the remaining disagreement concerns claim interpretation, the cited disclosure, or the support for an amendment. The applicant has a right to communicate orally and in writing, while additional personal interviews remain discretionary. Counsel should identify the proposed issues and amendments in advance and confirm the next procedural step after the discussion. The guidelines contemplate a record of substantive discussions and conclusions. Any agreed claim changes should still be submitted in the required form; an informal understanding does not itself supply the replacement claim set. (PCT art. 34(2)(a); WIPO, International Search and Preliminary Examination Guidelines ¶¶ 19.41–19.46.)

Prompt filing matters even when further amendments are permissible. The IPEA need not consider amendments or arguments received after it has begun drawing up the particular opinion or report. A submission can therefore arrive before issuance and still be too late for consideration. Once a response deadline has passed, counsel should confirm the examination timetable before relying on a late amendment to change the result. After preparation of the opinion or report has begun, the possibility that an examiner may consider a useful late submission is not an entitlement to consideration. (PCT R. 66.4bis; WIPO, International Search and Preliminary Examination Guidelines ¶ 20.05.)

Addressing unity and unsearched subject matter

 

The IPEA can raise lack of unity even if the ISA did not. It may invite the applicant to restrict the claims or pay additional examination fees, with a one-month response period. If the applicant fails to comply, examination may be confined to the main invention. An applicant disputing the assessment can pay the additional fees under protest with a reasoned statement; a separate protest fee may apply. Payment does not necessarily cure an absent international search, because claims directed to an unsearched invention need not be examined. These limits should be assessed before relying on Chapter II to obtain favorable findings for a newly selected invention. (PCT R. 68.2–68.5; WIPO, International Search and Preliminary Examination Guidelines ¶¶ 10.71–10.80; PCT R. 66.1(e).)

Completing the report and preparing for national entry

 

The report deadline is the latest of twenty-eight months from priority, six months from the time prescribed for starting examination, or six months from the IPEA’s receipt of a translation under Rule 55.2. Twenty-eight months is therefore not an unconditional completion date. The IPEA transmits the IPER and any annexes to the applicant and International Bureau on the same day. The Bureau communicates the report to elected offices under the applicable procedures, ordinarily no earlier than thirty months from priority, subject to the provisions for early national processing. (PCT R. 69.2; PCT R. 71.1; PCT R. 73.2.)

Counsel should verify which claims and amendments the completed report addresses, review its annexes, and identify any remaining objections for national counsel. The applicant remains responsible for translations of annexes where an elected office requires them. WIPO directs comments on the substantive content of the issued report to the elected offices during national proceedings. Chapter II thus concludes with an examination record that can inform national prosecution; it does not culminate in an international grant or refusal. (WIPO, PCT Applicant’s Guide, International Phase ¶¶ 10.078–10.079.)

National-entry preparations should continue while Chapter II is pending. The usual entry periods are thirty months from priority for the United States, China, and Japan, and thirty-one months for the EPO and South Korea. Filing the demand does not generally extend those periods, and a pending report should not be treated as permission to delay entry. A limited number of other offices retain distinctions under Articles 22 and 39 for which an election before nineteen months can matter; those exceptions require separate docketing. (WIPO, Time Limits for Entering National/Regional Phase Under PCT Chapters I and II.)

V What Chapter II costs

 

The immediate official cost consists principally of the preliminary examination fee charged by the IPEA and the handling fee. The authority chosen, the applicant’s eligibility for reductions, and additional inventions can affect the amount. Professional costs depend on the work needed to analyze the references, identify support, prepare amendments and arguments, and address subsequent communications. Translation and foreign-associate costs may also be relevant.

As of September 27, 2026, the following totals apply to examination by the USPTO when the ordinary $251 handling fee is payable. Each total includes that fee and the basic preliminary examination fee, but excludes additional inventions and professional costs. (USPTO, PCT Fees in US Dollars, International Phase Fees.)

USPTO acting as IPEA	Undiscounted	Small entity	Micro entity
USPTO also acted as ISA	$956	$533	$392
Another office acted as ISA	$1,131	$603	$427

U.S. small- or micro-entity status reduces the USPTO examination component but does not, by itself, reduce the ordinary handling fee. A separate ninety-percent handling-fee reduction is available under distinct PCT eligibility criteria. Examination of an additional invention by the USPTO ordinarily adds $705, $282, or $141 for the respective entity categories. (USPTO, PCT Fees in US Dollars, International Phase Fees.)

For the EPO, the standard preliminary examination fee is €2,010 and the ordinary handling fee is €215, producing a total of €2,225 before additional charges or applicable reductions. These figures illustrate why the authority selection and the expected national filings belong in the same cost analysis. They do not establish that the applicant is eligible to select the EPO in a particular case. (EPO, Fees for International Applications, applicable Apr. 1, 2026.) The IPEA competence restriction described in Section IV must therefore be checked before treating this fee example as an available alternative.

The economic comparison should credit only later savings that the application is expected to qualify for. A benefit already available from the international search cannot fairly be counted as an incremental return on Chapter II. Likewise, a benefit requiring favorable findings should not be treated as certain before the examination has produced those findings.

VI Reading the resulting IPER

 

The report must be read against the version of the application actually examined. Relevant questions include which amendments were considered, whether all claimed subject matter was examined, and whether lack of unity or other limitations affected the scope of examination. The report identifies the basis for its conclusions and addresses the claims individually; its findings do not attach indiscriminately to every claim formulation supported somewhere in the disclosure. (PCT R. 70.2, 70.9, 70.13.)

Box V contains the core findings concerning novelty, inventive step, and industrial applicability. Other portions of the report can contain qualifications or observations, including those in Box VIII. A report that is favorable on the three core criteria may therefore still present issues relevant to a particular national procedure. The report should be reviewed as a whole before counsel characterizes the result or relies on it for acceleration. (WIPO, International Search and Preliminary Examination Guidelines ¶ 17.10.)

The IPER does not determine whether the invention is patentable under any particular national law. A positive result does not create a patent or compel allowance; a negative result does not itself foreclose national prosecution. Its practical value lies in the claim-specific analysis and the procedures for which that analysis qualifies. (PCT art. 35(2); PCT art. 33(1), (5).)

VII Effects in national and regional examination

 

United States

 

For an application entering the United States under 35 U.S.C. § 371, favorable findings by the USPTO acting as ISA or IPEA can have specific financial consequences. If those findings cover all claims presented in the national-stage application, the national-stage search and examination fees are zero. The basic national fee and other applicable charges remain. A favorable report from a foreign authority does not independently establish eligibility for these zero fees. (37 C.F.R. § 1.492(b)(1), (c)(1); MPEP § 1893.03; USPTO, Fee Schedule, National Stage Fees.)

Applications receiving that treatment are advanced out of turn, but the associated amendment restriction deserves attention before national-stage processing begins. Section 1.496 limits subsequent amendments to eliminating formal objections or canceling rejected claims. Applicants expecting significant claim revision should account for that restriction when planning the national filing. These provisions concern § 371 applications and should not be assumed to apply to an ordinary § 111(a) bypass continuation. (37 C.F.R. § 1.496; MPEP § 1893.03.)

PCT-PPH supplies a separate route to accelerated U.S. examination based on qualifying international findings, including those from participating foreign authorities. The request must meet the applicable correspondence and timing requirements. A qualifying USPTO written opinion from Chapter I may already establish the domestic-authority fee benefit, so Chapter II is not invariably necessary. (USPTO, Patent Prosecution Highway; MPEP § 1893.03.)

European Patent Office

 

The EPO reduces its later European examination fee by seventy-five percent where it established the international preliminary examination report. The reduction does not depend on favorable findings. Where the report covered only part of the international application, the reduction is unavailable if the European examination is to address subject matter outside that coverage. The benefit should therefore be evaluated against the subject matter the applicant actually intends to pursue. (EPO Rules Relating to Fees art. 14(2).)

A positive EPO opinion has a separate procedural effect. Under the Rule 161(1) procedure, substantive comments or amendments responding to a positive relevant EPO opinion are voluntary; a negative opinion ordinarily requires a response. A positive opinion does not itself eliminate the Rule 161 communication or the remaining European examination. (EPO Guidelines for Examination A-XIV, § 3 (2026).)

There can also be practical continuity. The EPO explains that its IPER is usually prepared by the examiner who later handles the European phase. Resolving an issue internationally may therefore help the later examination, although the application remains subject to examination under the EPC. (EPO Guidelines for Examination A-XIV, § 6.3 (2026).)

The EPO’s own international work does not provide a basis for PPH before the EPO itself. Its IP5 participation notice excludes applications for which it acted as ISA and/or IPEA from PPH processing before it as designated or elected Office, because that route relies on another office’s examination work. An applicant in that situation may instead request acceleration through the applicable PACE procedure. The European examination-fee reduction and the possibility of PACE are distinct from PPH eligibility. (EPO, IP5 PPH Programme Notice, OJ EPO 2022, A115, pt. II.B(1) n.1.)

China

 

A qualifying foreign IPER can support PCT-PPH at CNIPA. Under the IP5 guidelines, the application must satisfy publication and substantive-examination-stage requirements, with an exception allowing the PPH request to accompany the substantive examination request. Examination must not already have begun. The same guidelines exclude a PCT-PPH request where the supporting international opinion or report contains observations in Box VIII. Favorable core patentability findings therefore do not necessarily establish Chinese PCT-PPH eligibility. (CNIPA, IP5 PPH Guidelines pt. II, §§ 1(1), 1(4)–(7).)

China’s fee exemption has a different basis. CNIPA’s 2024 fee announcement exempts the national substantive examination fee where CNIPA issued the ISR or international preliminary report on patentability. The rule does not condition that exemption on a positive result. A positive USPTO or EPO IPER alone does not supply the CNIPA-work condition. (CNIPA Announcement No. 594, § V (Aug. 6, 2024).)

South Korea

 

South Korea permits PPH requests based on qualifying international work and provides greater timing flexibility than several other offices: participation can be requested even after examination has begun. An examination request must accompany or precede the PPH request, and the applicable claim-correspondence and supporting-document requirements still apply. The Korean office is now the Ministry of Intellectual Property (MOIP), formerly KIPO. (MOIP, IP5 and Global PPH Procedures; JPO, IP5 PPH Portal, Requirements.)

The Korean examination fee is reduced by seventy percent where MOIP established the ISR and/or IPER. This reduction is linked to the Korean authority’s work, rather than to a favorable opinion from any office. If MOIP already conducted the international search, the reduction should not be counted again as a new benefit obtained by paying for Chapter II. (WIPO, PCT Applicant’s Guide, Republic of Korea, National Phase, Fee Reductions, valid Aug. 1, 2026.)

Japan

 

Japan permits PCT-PPH based on qualifying international work products, subject to sufficient correspondence between the Japanese claims and favorable claims and to the requirement that examination has not begun. A favorable WO/ISA can be an eligible work product, so a Chapter II report is not always necessary to obtain that procedural benefit. (JPO, PCT-PPH, Requirements.)

The Japanese examination-fee reduction instead depends on the international search. For international applications filed on or after April 1, 2019, the standard fee is ¥83,000 plus ¥2,400 per claim where JPO prepared the ISR, and ¥124,000 plus ¥3,600 per claim where another ISA prepared it. Those amounts are before any separate applicant-based reductions. Obtaining a positive Chapter II report does not itself create an additional discount under that fee structure. (WIPO, PCT Applicant’s Guide, Japan, Annex JP.I, valid July 1, 2026.)

VIII Coordinating claim strategy with PCT PPH

 

PPH accelerates examination of a qualifying application; it does not transfer the issuing authority’s conclusions into a binding national allowance. The applicable arrangement must accept the authority and work product being used. The IP5 program includes PCT work products among the participating offices, and the current continuation runs through January 5, 2029. (WIPO, Patent Prosecution Highway and the PCT, at 4–5; CNIPA, IP5 PPH Pilot Program Extended (Dec. 31, 2025).) For the EPO, the distinction between another office’s work and its own international work is addressed in Section VII.

The IP5 description and the EPO’s participation requirements call for the latest relevant PCT work product. Where that requirement governs, an earlier favorable WO/ISA should not be assumed to remain usable after a later IPER reaches adverse conclusions on the claims relied upon. This consequence follows from the latest-work-product condition; it is not a universal rule for every PPH arrangement. Nor does an adverse finding on some claims necessarily defeat eligibility based on other claims that remain favorable, provided the destination office’s requirements, including claim correspondence, are satisfied. (IP5 Offices, IP5 Patent Prosecution Highway, Bases for a PPH Request; EPO, IP5 PPH Programme Notice, OJ EPO 2022, A115, pts. II.B(2)–(3), II.C(3).)

At least one favorable claim may be enough to provide the starting point, but all claims submitted for PPH examination must sufficiently correspond to favorable claims under the relevant program. Correspondence can accommodate translation and claim-format differences and, where permitted, supported narrowing. It does not automatically encompass a broader claim or a newly introduced claim category. A claim correspondence table should make the relationship clear. (CNIPA, IP5 PPH Guidelines pt. II, §§ 1(3), 2(4); JPO, PCT-PPH, Requirements.)

Consider a claim directed to A+B+C that becomes favorable only after adding limitation D. The favorable finding concerns the amended combination. If D captures a feature central to the product and difficult to avoid, the amendment may support both meaningful protection and an acceleration strategy. If D is incidental, obtaining the favorable report may have little commercial value. Pursuing broader or differently framed claims nationally requires a separate assessment of patentability and the effect on PPH eligibility.

Coordination with national counsel is therefore useful before settling the international claim set. The discussion should identify local claim-format requirements, supported fallback positions, and the implications of the proposed arguments. Because the legal effect of prosecution statements can differ by jurisdiction, the analysis should avoid assuming that one uniform international estoppel rule governs every later proceeding.

IX Applying the decision to practical cases

 

Suppose an applicant plans filings in the United States, Europe, China, South Korea, and Japan, and the WO/ISA overlooks a disclosed control relationship already present in a dependent claim. If that relationship distinguishes the cited art and remains commercially important, Chapter II may offer a useful opportunity to obtain favorable findings on an amended claim set. The applicant can then evaluate each national acceleration route and fee rule against the actual report, rather than assuming that a positive result produces identical consequences everywhere.

Now suppose the WO/ISA is already favorable on the claims intended for national filing. If those findings already support the contemplated PPH requests, the applicant should identify a separate reason to incur Chapter II costs. That reason might concern an authority-specific financial benefit or an additional amendment requiring examination. Repeating the examination solely to obtain a report bearing a different procedural title may add little value.

A third applicant may be able to overcome the international objection only by adding a feature that competitors can readily omit. In that case, direct national prosecution of commercially useful claims may be preferable, even if it leaves the applicant with an unfavorable international report. The relevant objective is useful patent protection, and the report is one input into that strategy.

Before filing the demand, counsel should be able to identify the objection the proceeding is intended to resolve, the supported claim scope likely to emerge, and the specific national benefit expected from the resulting work product. That assessment should account for deadlines, professional costs, verified fee treatment, and any amendment restrictions. A Chapter II demand is most defensible when those facts establish a concrete reason for completing an additional international examination before national entry.