Legal Evaluation of Each Statement
USCO filed two PCT applications entering the EP regional phase in June 2025:
- PCT-U: searched by USPTO as ISA; lack of unity found; only U1 searched.
- PCT-E: searched by EPO as ISA; lack of unity found; only E1 searched.
On EP entry, claims first mentioned U1 and E1 respectively. USCO now wants to prosecute only U2 and E2 in Europe.
- The legal consequences differ depending on whether the EPO does or does not perform a supplementary European search upon EP entry.
(1) If the EPO did not act as ISA (PCT-U): supplementary European search applies
Where the EPO did not act as ISA/SISA, it performs a supplementary European search. Amendments filed within the Rule 161/162 time limit are taken into account for drawing up that supplementary search report.
If the EPO considers unity lacking for the documents serving as basis for the supplementary search, it draws up a partial supplementary search report on the invention first mentioned in the claims (Rule 164(1)(a)) and can invite payment of further search fees for additional inventions (Rule 164(1)(b)).
(2) If the EPO did act as ISA (PCT-E): no supplementary search; Rule 164(2) mechanism
Where the EPO acted as ISA/SISA, it normally does not draw up a supplementary European search report. If the claims forming the basis for examination contain an invention not covered by the international search, the examining division issues a Rule 164(2) communication inviting payment of search fees for those unsearched inventions, allowing the applicant to have them searched and then to pursue one searched invention in examination.
The Guidelines summarise that, in such cases, the application must ultimately be limited to an invention searched either in the international phase by the EPO or in the European phase in a search under Rule 164(2)(a).
Legal Evaluation of Each Statement
a) The client can inform the EPO that he wishes both applications to be prosecuted on the basis of PCT-U2 and PCT-E2. — False
A mere “information” or wish is not procedurally sufficient.
For PCT-U2, the applicant must amend the claims so that U2 becomes the invention first mentioned in the claims serving as basis for the supplementary search.
For PCT-E2, it is not enough to amend to E2: if E2 is unsearched, the applicant must be prepared to pay the additional search fee when invited under Rule 164(2) so that E2 becomes a searched invention that can be pursued.
So “informing” alone does not achieve the intended legal effect.
b) The client can wait to receive the Rule 161 EPC communication to limit the claims of the EP application corresponding to PCT-U to PCT-U2. — True
For PCT-U (EPO not ISA), amendments filed within the Rule 161/162 time limit are taken into account for the supplementary European search.
Therefore, the applicant may wait for the Rule 161/162 communication and then amend so that U2 is the invention first mentioned in the claims; the supplementary search will then be based on that claim set (and thus on U2).
(Practically, earlier amendment is often safer/faster, but the statement asks whether they can wait.)
c) The client can wait to receive the Rule 161 EPC communication to limit the claims of the EP application corresponding to PCT-E to PCT-E2. — True
For PCT-E (EPO was ISA), the applicant can amend within the Rule 161/162 time limit so that the claims to be examined are directed to E2.
If E2 was not covered by the international search, the examining division then issues a Rule 164(2) invitation allowing E2 to be searched upon payment of the required search fee(s).
So the applicant can pursue E2 in the European phase without being forced into a divisional, provided the Rule 164(2) fee route is used.
d) The applicant needs to file divisional applications to have PCT-U2 and PCT-E2 considered by the EPO. — False
Not needed in this fact pattern:
- PCT-U2 can be made the basis of the supplementary European search by amending within the Rule 161/162 time limit so that U2 is first mentioned.
- PCT-E2 can be searched in the European phase via Rule 164(2) upon payment of the additional search fee(s), and then pursued in examination.
A divisional remains an option in some strategies, but it is not a requirement to have U2/E2 considered.
Exam Tip:
When you see “Euro-PCT + lack of unity + only first invention searched”, immediately split into two tracks:
- EPO not ISA → Rule 164(1) (supplementary search):
Amend within Rule 161/162 so your preferred invention is first mentioned in the claims for the supplementary search. - EPO was ISA → Rule 164(2) (no supplementary search):
If you switch to an unsearched invention, expect a Rule 164(2) invitation and you must pay to get it searched; otherwise you’ll be forced to delete unsearched subject-matter.
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.