What is required if an examiner finds a "lack of unity" in an International Application?

When an examiner identifies a "lack of unity" in an International Application, additional fees must be paid for reconsideration. The principle of unity of invention requires that an international application must relate to a single invention or a group of inventions that are so connected as to form a single general inventive concept. If the application presents multiple inventions that are not linked adequately, the examiner will issue a lack of unity notice.

In such a case, the applicant is then given the option to pay additional fees for each additional invention claimed, which allows the examination of those inventions to proceed. Therefore, payment of additional fees is essential if the applicant wishes to continue pursuing protection for the multiple inventions through the same international application, rather than having to file separate applications for each invention, which could lead to extra costs and complexity. This highlights the importance of adhering to the requirements for unity in patent applications to streamline the examination process.