In reply to an objection of lack of unity, the applicant must restrict the claims to a single invention which has been searched, unless the applicant can convince the examining division that the objection was not justified.

If the claims have been restricted to a single searched invention, the examination can be continued as for a unitary application but limited to that invention (see C‑III, 3). If the objection is withdrawn in view of the arguments put forward by the applicant, an additional search may be necessary (see C‑IV, 7.2) in order for the examination of the claimed invention to be continued.

However, if in response to a negative opinion concerning that invention the applicant later amends the claims to switch to a different searched invention, the division will exercise its discretion under Rule 137(3) and refuse to admit the amendments since only one invention in each application can be examined for conformity with the requirements of the EPC (see G 2/92 and T 158/12).