PCT Newsletter

June 2026 | No. 06/2026

Practical Advice 

Communications usually received from Offices during the international phase under Chapter I of the PCT 

Q: I’ve just filed a PCT application. What communications will I receive during the international phase, assuming no defects in formalities are found in my application?

A: After you have filed an international application under the PCT, you will receive a range of notifications, invitations and other communications from the receiving Office (RO), the International Bureau (IB) and the International Searching Authority (ISA). In ordinary circumstances – that is, where no formalities defect has been found in the PCT application as submitted – you will receive the communications outlined below. (Note that this overview does not cover communications relating to international preliminary examination under Chapter II of the PCT.)

You need to carefully monitor the arrival of each communication and check its content. Make sure that the data it contains match your internal records. Do not wait until the application has been published to detect and correct errors, as some important time limits for remedial actions will have expired by that time.

PCT/RO/105 Notification of the international application number and of the international filing date

If the conditions for according an international filing date are fulfilled on the date on which the receiving Office receives the application, the receiving Office will accord that date as the international filing date and notify the applicant (PCT Article 11(1) and Rule 20.2). You need to check that you receive this important notification, which is usually issued within the first month after the application has been filed. Make sure the accorded filing date is the date you expected and that other information in the notification is correct; if not, you need to consider requesting corrections following the applicable procedures.  

PCT/RO/150 Invitation to furnish translation

Where a PCT application has been filed in a language which is not accepted by the competent ISA, you need to furnish a translation into a language accepted by that ISA within one month from the filing date. If a translation has not yet been furnished, the RO will invite you to do so. The procedure is outlined in PCT Rule 12.3. 

PCT/RO/102 Notification concerning payment of prescribed fees
The transmittal fee, international filing fee and international search fee must be paid within one month after filing (PCT Rules 14, 15 and 16). Generally, you will receive this notification concerning payment together with the notification of the international filing date. Any electronic filing system will have calculated the amounts in question. This notification indicates any balance due; you should check the figure and pay it as soon as possible, bearing in mind that the RO will not transmit a copy of the application (the search copy) to the ISA until the search fee has been paid (PCT Rule 23.1(a)). If all due fees are not paid within the month, the RO will issue Form PCT/RO/133: Invitation to pay with a late payment fee, applying the procedure outlined in PCT Rule 16bis.
PCT/IB/301 Notification of receipt of record copy 
The IB should notify you that it has received from the RO – after any national security clearance that may be required – a copy of the international application (the record copy) (PCT Rules 22.1 and 24.2). The record copy will be used for international publication and other processing of the application at the IB.
PCT/ISA/202 Notification of receipt of search copy
The ISA should notify you of the date on which it has received the search copy, based on which it will perform the international search (PCT Rules 23 and 25). The international search report and the written opinion of the ISA will usually be established within three months from this date. 

PCT/ISA/220 Notification of transmittal of the international search report (ISR) and the written opinion of the ISA, or the declaration 
PCT/ISA/210 International search report (or PCT/ISA/203 Declaration of non-establishment of ISR), and
PCT/ISA/237 Written opinion of the ISA 

At about 16 months from the priority date, the ISA should send you the results of the international search, namely, the ISR and the written opinion of the ISA (PCT Articles 17 and 18, Rules 43, 43bis and 44). Form PCT/ISA/220 is sent along with the results as a cover page. If the ISA decides not to establish the ISR, for example, because the application relates to an excluded subject matter, it will substitute the report with a declaration to this effect. 
PCT/IB/304 Notification concerning submission, obtention or transmittal of priority document
If your application contains a priority claim and you have submitted the priority document, the IB will notify you when it has received the priority document or obtained the document via the Digital Access Service (DAS), and, in the case of multiple priority claims, whether all priority documents have been received. Make sure you receive this form; if it has not been received within a reasonable time after you furnished the priority document or DAS access code, you need to investigate – where possible within the time limit to correct priority claims (PCT Rule 26bis) – in case there was an issue with the priority claim. The same applies where more than one priority is claimed and the letters “NR” appear next to a priority claim. For details on furnishing priority documents, please see PCT Rule 17.1.
PCT/IB/311 Notification concerning availability of the publication of the international application
The IB will use this notification to inform you that the international application has been published on PATENTSCOPE (PCT Article 21 and Rule 48) on a certain date with a specific publication number. The content of your application will be disclosed to the public from this date, and the publication can be cited using the publication number. 

PCT/IB/308 Second[1]  and supplementary notice informing the applicant of the communication of the international application (to designated Offices which apply the 30-month time limit under Article 22(1))

Usually at 28 months from the priority date, the IB will send you this notice to inform you that it has transmitted your application to all those national Offices that require such transmittal. For national Offices that do not require such transmittal, this notice serves as conclusive evidence that the application was made available for download to all such designated Offices. As a result, you as the applicant do not need to furnish a copy of your international application to any of the designated Offices. Moreover, the notice is also a timely reminder to applicants that the time limit for entering the national phase is approaching. 

PCT/IB/326 Notification concerning transmittal of copy of international preliminary report on patentability (PCT Chapter I)
PCT/IB/373 International preliminary report on patentability (PCT Chapter I). 

At 30 months from the priority date, if no demand for international preliminary examination has been filed, the IB will, on behalf of the ISA, convert the written opinion of the ISA into an international preliminary report on patentability (Chapter I) for communication to the designated Offices, and will send a copy to the applicant with the above Form (PCT Rules 44bis.1 and 44bis.2).
PCT/IB/374 Notification of transmittal of copies of translation of the written opinion of the ISA
Also at 30 months, where the written opinion of the ISA was not established in English, the IB will translate it into English for the designated Offices and send a copy to the applicant (PCT Rules 44bis.3 and 72).
The above list covers the communications that you should receive as an applicant during the international phase under Chapter I of the PCT. If you receive any other PCT-related invitations or communications, you need to read them with particular care, especially where the international filing date or a priority claim are in question. They may relate to formality defects, some of which may be remedied within certain time limits, otherwise loss of rights may occur.

[1] The first notice is sent earlier, after 19 months, and concerns only Luxembourg and the United Republic of Tanzania, which do not apply the 30-month time limit for national phase entry.

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