3.3 Amended claims, missing parts (Rule 56) or erroneously filed application documents or parts (Rule 56a)
3.3.2 Specific rules applicable to Euro-PCT applications
Where a European application derives from an earlier international application, the applicant may have amended the international application in the international phase, either after receiving the international search report (Art. 19(1) PCT) or during international preliminary examination (Art. 34(2)(b) PCT). Under Rule 159(1)(b), the applicant can then choose whether to enter the European phase with these amended application documents (including claims) or with the ones originally filed. The EPO also gives them an opportunity to amend the application documents (including the claims) within a set time limit (Rule 161(2), see E‑IX, 3). The application as amended is then taken as the basis for any supplementary European search to be carried out under Art. 153(7) (see B‑II, 4.3 and B‑XI, 2).
See B‑VIII, 6 for the procedure followed where the claims of an international application entering the European (regional) phase are amended in such a way that they contravene Art. 123(2).