The question who owns the IP rights can be quite a challenge as IP rights can be transferred, reassigned, or sold. In the WPI files the assignee data from other family members can provide a hint that ownership has changed. The INPADOC file contains 14.8 mil records dealing with a Legal tatus code that deals with changes in owner, inventor or applicant. The IFICLS file contains over 5.3 mil records describing reassignments of patent rights. Later this year, the CAplus file will also include a field with the ultimate owner of the patent rights. In this coffee lecture we will outline some of the search strategies to find the original and current (or ultimate) owners of patents.