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, it indicates that the application includes multiple inventions that are not sufficiently linked. In such cases, the examiner will require a response from the applicant, which often entails the payment of additional fees for the examination of the non-unified inventions. This practice aligns with the international patent system's requirements, where applicants may need to select which inventions they wish to pursue further.

Thus, the requirement to pay additional fees to have additional inventions examined is a necessary and procedural step to move forward with the application. It allows for a structured approach to handle multiple inventions under a single application while ensuring that the proper examination process is followed.