It is important to understand that all submissions must be original compositions created by you, the songwriter. If the composition was not created by you, it is owned and/or controlled by another songwriter and publisher, and cannot be submitted for publishing administration.
Original compositions include music and lyrics that are completely created by you. For instance, a song like “If I Were a Boy” recorded and released by Beyonce in 2008, while popular, is technically a cover of a song originally written by BC Jean and Toby Gadd. Therefore, Beyonce would not be able to submit this for publishing administration. The composition BC Jean and Toby Gadd wrote is controlled by them and their respective publishers. However, if they did not have a pre-existing publishing agreement, that song could be submitted for publishing administration with UniteSync.
On the other hand, if Beyonce co-wrote a song like “Drunk In Love”, she would be able to submit it for publishing administration. However, a cover of the song by a third party like Ed Sheeran would not be able to be submitted.