Unity is assessed in the same way in the PCT and European procedures. However, the consequences of a finding of lack of unity at the search and/or examination stages are different under the PCT, as are the actions to be taken by the examiner. In particular, the applicant may be asked to pay additional search and/or examination fees and may do so under protest.
Furthermore, divisional applications are not allowed under the PCT.
Source: http://www.epo.org/law-practice/legal-texts/html/guidelinespct/e/b_vii_1.htm
Date retrieved: 17 May 2021