What is the Copyright Office policy regarding registration of published and unpublished works?
The Office strongly encourages creators to register their works before they are published, because this avoids much of the confusion concerning publication and the treatment of published works.
Where there is uncertainty as to whether a work is published or unpublished, and if the registration requirements for the particular work require the applicant to submit two copies with the application, it may be advisable to assume that the work has been published and register that work on an individual basis. If the registration is later challenged in court, this may eliminate any deficiency in the deposit requirement that could affect the effective date of registration and potentially the validity of the registration. However, the Office is not aware of a case where the failure to submit two copies with the application was held to be a material defect in the registration that would warrant invalidation of the registration.
A more significant concern would be if the applicant sought to register multiple works as an unpublished collection or as a group of published photographs and mischaracterized the publication status of those works. Published works cannot be registered in an unpublished collection and if the Copyright Office knew that a particular work was published, the applicant would be required to exclude that work from the collection. Similarly, unpublished works are ineligible for the group registration option for published photographs, and if the Copyright Office knew that a particular photo was unpublished, the applicant would be required to exclude that photo from the group. Thus, additional care must be exercised when registering multiple works with these registration options.
Rob Kasunic, Director of Registration Policy and Practices at the U.S. Copyright Office