Legal framework
Under Article 8(1) PCT, an international application may claim the priority of an earlier application. The conditions and effect of the priority claim are governed by Article 4 of the Paris Convention, according to Article 8(2)(a) PCT.
For PCT purposes, Rule 2.4(a) PCT defines the priority period as 12 months from the filing date of the earlier application, and the day of filing of the earlier application is not included in that period. Rule 2.4(b) PCT further provides that Rule 80.5 PCT applies mutatis mutandis to the priority period.
Under Rule 80.5 PCT, if the expiry of a period falls on a day on which the relevant Office is not open to the public for official business, the period expires on the next subsequent day on which that circumstance no longer exists.
The EPO’s Euro-PCT Guide confirms that if the last day of the priority year falls on a non-working day or an official holiday of the EPO, the priority year expires on the next subsequent working day. It also confirms that Rules 82 and 82quater PCT, concerning postal irregularities and force majeure, do not apply to the 12-month priority period, because that period is fixed by the Paris Convention, not by the PCT Rules.
Calculation of the priority period
DE-X was filed on 14 June 2024.
The 12-month priority period therefore nominally ended on 14 June 2025. However, 14 June 2025 was a Saturday. Since the EPO was not open for official business, the period was extended under Rule 80.5 PCT to the next working day, namely Monday 16 June 2025.
PCT-X reached the EPO only on 18 June 2025. Under Article 11(1) PCT, the international filing date is the date of receipt of the international application by the receiving Office, provided the filing-date requirements are met. Thus, the filing date is 18 June 2025, which is after expiry of the priority period.
Statement a)
Statement a) is false.
The priority is not validly claimed as a normal priority claim, because the international application was received on 18 June 2025, after expiry of the priority period on 16 June 2025.
The fact that PCT-X was sent by registered letter on 12 June 2025 does not save the priority claim. The relevant date for the international filing date is the date of receipt by the receiving Office, not the date of posting. Moreover, postal delay provisions such as Rule 82 PCT do not apply to the 12-month priority period.
However, since PCT-X was filed within two months from expiry of the priority period, the applicant may seek restoration of the right of priority.
Statement b)
Statement b) is false.
The statement says that the time limit expired on 14 June 2024, which is the filing date of DE-X itself. That is plainly incorrect.
The priority period was 12 months from the filing date of DE-X. It therefore nominally expired on 14 June 2025. Since that date was a Saturday, the period was extended under Rule 80.5 PCT to Monday 16 June 2025.
Statement c)
Statement c) is false.
Restoration of the right of priority under Rule 26bis.3 PCT is requested from the receiving Office. The EPO’s Euro-PCT Guide expressly states that, where an international application is filed after expiry of the priority period, a request for restoration may be filed with the EPO as receiving Office.
The statement refers instead to the EPO acting as International Searching Authority. That is the wrong capacity. The ISA performs the international search; it does not decide on restoration of the right of priority under Rule 26bis.3 PCT.
Statement d)
Statement d) is true, provided “re-establishment” is understood as the PCT request for restoration of the right of priority.
Under Rule 26bis.3(e) PCT, the time limit for requesting restoration is two months from the date on which the priority period expired. The EPO as receiving Office requires the request, the restoration fee and the statement of reasons to be filed within that same two-month period.
Here, the priority period expired on 16 June 2025. Two months from that date leads to 16 August 2025. Since 16 August 2025 was a Saturday, the period is extended under Rule 80.5 PCT to the next working day, namely Monday 18 August 2025.
Therefore, the final date for filing the request is 18 August 2025.
Exam tip
For late PCT filings, distinguish three questions carefully:
First, calculate the priority period. Here, 14 June 2025 was a Saturday, so the priority period expired on 16 June 2025.
Second, remember that the international filing date is the date of receipt, not the date of posting. A registered letter posted before the deadline does not itself secure the filing date.
Third, restoration of priority is requested before the receiving Office, not the ISA. In this case, the correct route is a request under Rule 26bis.3 PCT before the EPO as receiving Office, due by 18 August 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.