Legal framework
Under Article 87(1) EPC, a European application may validly claim priority from an earlier application for the same invention within twelve months from the filing date of the first application. Here, EP1 was filed on 1 June 2023. The twelve-month priority period normally ended on 1 June 2024, but that date was a Saturday. Under Rule 134(1) EPC, where a period expires on a day on which the EPO filing offices are not open for receipt of documents, the period is extended to the next day on which they are open. Thus filing EP2 on Monday 3 June 2024 is still within the extended priority period.
The effect of a valid priority claim is that the priority date counts as the filing date of the European application for the purposes of Article 54(2) and Article 54(3) EPC: Article 89 EPC.
For priority to be valid for a claim, the claimed subject-matter must be directly and unambiguously derivable from the priority application as a whole. This is the “same invention” test in G 2/98, also reflected in the Guidelines, F-VI, 2.2.
Article 54(3) EPC prior art consists of earlier European applications published on or after the relevant date of the later application. Such earlier applications are relevant only for novelty, not inventive step. This follows from Article 56 EPC, second sentence, and Guidelines G-IV, 5.1.
Statement a)
False.
Claim 2 is directed to the combination of features B and A.
EP1 discloses feature B but not feature A. Therefore, claim 2 as a combination of A+B is not entitled to the priority date of EP1, because the combination is not directly and unambiguously derivable from EP1. The effective date for claim 2 is therefore the actual filing date of EP2, 3 June 2024.
US1 was published on 1 February 2023 and discloses feature A. It is therefore Article 54(2) EPC prior art. But US1 alone does not disclose feature B.
EP1 was published only in December 2024, after the filing date of EP2. It is therefore not Article 54(2) EPC prior art against EP2. At most, EP1 may be Article 54(3) EPC prior art for subject-matter not entitled to priority. However, Article 54(3) EPC prior art is not considered for inventive step under Article 56 EPC, second sentence.
Thus, even though A+B would be obvious if the skilled person combined US1 with EP1, that combination cannot be used for an inventive-step objection because EP1 is not usable for inventive step.
Statement b)
False.
Claim 1 is directed to feature B. Since EP1 discloses feature B, claim 1 validly benefits from the priority date of EP1, namely 1 June 2023.
If EP2 had not claimed priority from EP1, claim 1 would have the filing date of EP2, 3 June 2024. EP1, filed on 1 June 2023 and published in December 2024, would then be an earlier European application published after EP2’s filing date. It would therefore be Article 54(3) EPC prior art against claim 1.
Because EP1 discloses feature B, it would destroy the novelty of claim 1 if no priority were claimed.
Therefore, the patentability of claim 1 would change.
Statement c)
False.
As EP2 does claim priority from EP1, and claim 1 is directed to feature B disclosed in EP1, claim 1 has the effective date 1 June 2023 under Article 89 EPC.
EP1 itself also has the filing date 1 June 2023. For Article 54(3) EPC to apply, the earlier European application must have a filing or valid priority date earlier than the relevant date of the application being examined. EP1 is not earlier than claim 1’s effective date; it has the same date.
Moreover, EP1 was published in December 2024, so it is not Article 54(2) EPC prior art against claim 1 either.
Thus, no valid novelty objection can be made using EP1 against claim 1.
Statement d)
True.
Claim 2 is directed to the combination A+B.
US1 discloses feature A but not feature B. EP1 discloses feature B but not feature A. Neither document discloses the combination of features A and B in a single prior-art disclosure.
For novelty, documents are not combined. Since no single cited document discloses A+B, the subject-matter of claim 2 is novel.
Exam tip
In priority/self-collision questions, work claim by claim. First assign the effective date for each claim. Then classify each document as Article 54(2) or Article 54(3) prior art. Finally, remember the golden rule: Article 54(3) EPC prior art can be used only for novelty, never for inventive step.
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.