In many and probably most instances, lack of unity will have been noted at the search stage. In such cases, a search is conducted for the invention first mentioned in the claims and the applicant is invited to pay additional search fees with Form PCT/ISA/206. See GL/PCT‑EPO B‑VII, 2.[Art. 17(3)(a); Rule 40; 45bis.6; ]

See also ISPE Guidelines 10.60 for the process at the international search stage and ISPE Guidelines 10.83 for the process at the supplementary international search stage.