618.8 (B) Percentage of Authorship
The U.S. Copyright Office strongly discourages applicants from using numerical percentages to describe an author’s contribution to a work, such as “music by Joe Goldie (50%); lyrics by Pepe Greenwald: (50%).” As discussed in Section 619, a copyright may be registered by or on behalf of the author of the work or a person or entity that owns all rights under the copyright that initially belonged to the author. 37 C.F.R. § 202.3 (A) (3). Providing percentages in the Author Created field or the Nature of Authorship space may imply that the work is a joint work or it may raise a question as to whether the person or persons named in the application contributed copyrightable authorship to the work or whether the claimant owns all of the exclusive rights in the work.
If the applicant provides a percentage in the Author Created field or the Nature of Authorship space, the registration specialist may register the claim without communicating with the applicant if it is clear that the authors named in the application contributed copyrightable authorship to the work and if the work appears to be jointly owned. The percentage is considered superfluous in this situation, because it presumably refers to some allocation among the co-authors or co-owners of the copyright, rather than an allocation of the ownership in the copyright as a whole.