Legal framework
Under PCT Rule 54bis.1(a), a demand for international preliminary examination may be made before expiry of whichever of the following periods expires later:
First, three months from the date of transmittal to the applicant of the international search report and the written opinion of the ISA.
Second, 22 months from the priority date.
If the demand is filed after expiry of the applicable time limit, it is considered as if it had not been submitted: PCT Rule 54bis.1(b). The EPO PCT Guidelines confirm this in C-II, 1.1.
Periods expressed in months are calculated under PCT Rule 80.2. If a PCT period expires on a day on which the relevant Office or organisation is not open, the period expires on the next subsequent day on which the relevant circumstances no longer exist: PCT Rule 80.5.
Calculation
The international application claims priority from a European patent application filed on 16 January 2024. Therefore, the relevant priority date is 16 January 2024.
The international search report and written opinion were transmitted on 3 July 2025.
The first possible period is therefore:
3 July 2025 + 3 months = 3 October 2025.
However, 3 October 2025 was Day of German Unity, and the EPO’s 2025 closure notice lists it as a closing day relevant for PCT proceedings under Rule 80.5 PCT. The period is therefore extended to Monday 6 October 2025.
The second possible period is:
16 January 2024 + 22 months = 16 November 2025.
16 November 2025 was a Sunday. Under PCT Rule 80.5, the period is extended to the next working day, namely Monday 17 November 2025.
The later of the two dates is therefore 17 November 2025.
Statement a)
False.
The date 16 November 2025 is the unextended expiry date of the 22-month period from the priority date. Since it fell on a Sunday, the deadline is extended under PCT Rule 80.5 to Monday 17 November 2025.
Statement b)
True.
The 22-month period from the priority date, 16 January 2024, expires on 16 November 2025. Because this was a Sunday, the deadline is extended to 17 November 2025.
This is later than the extended three-month period from transmittal of the ISR and WO-ISA. Therefore, 17 November 2025 is the last day for filing the demand.
Statement c)
False.
The date 3 October 2025 corresponds to three months from the transmittal of the ISR and WO-ISA on 3 July 2025.
However, this date is not the applicable final deadline for two reasons. First, it was an EPO closing day for PCT purposes. Second, even after extension to 6 October 2025, it is earlier than the 22-month deadline extended to 17 November 2025.
Statement d)
False.
The date 6 October 2025 is the extended expiry date of the three-month period from transmittal of the ISR and WO-ISA.
But PCT Rule 54bis.1(a) requires taking the later of the three-month period and the 22-month period from priority. The later date is 17 November 2025, not 6 October 2025.
Exam tip
For a demand under Chapter II PCT, always calculate both alternatives under PCT Rule 54bis.1(a). Then extend each date separately if it falls on a non-working day under PCT Rule 80.5. Only after doing that should you compare the two dates and choose the later one. Here, the correct last day is 17 November 2025, not 6 October 2025.
Legal Disclaimer
The information provided in this post is for general informational purposes only and does not constitute legal advice. This content should not be used as a substitute for professional legal advice tailored to your specific circumstances. For advice related to any specific legal matters, you should consult a qualified attorney.