10.1 General procedure 

In case of non-unity only one invention is searched; there is no possibility to pay additional fees for further inventions. Furthermore, the decision as to which invention should be considered the main invention and thus searched is handled differently for the SIS procedure, as set out in detail in GL/PCT‑EPO B‑XII, 10.2.

Where the main ISA has already objected to lack of unity, the applicant can indicate together with the supplementary search request which of the inventions should be searched by the SISA. For further details see GL/PCT‑EPO B‑XII, 10.3.

If on the other hand the main ISA has not objected to lack of unity, the EPO as SISA is free to do so, as the SISA is not bound by any finding on unity made by the ISA but merely obliged to take such a finding into account.

As for any international search where lack of unity is objected to, the applicant has the right to protest against the non-unity finding. In the SIS procedure this protest is called a review (see GL/PCT‑EPO B‑XII, 10.4).