The copyright of a self-published work would always belong to the author. This is because the author has the right to decide on his own work and bear the publishing and distribution costs. Therefore, the author had the copyright and the right to use it for commercial purposes. However, the author could earn royalties or other forms of economic benefits by selling the copyright after it was sold. Royalties are calculated based on the number of sales or sales of the work, so if the work is sold in large quantities, the author may receive higher royalties. However, it should be noted that royalties are only a part of the economic benefits obtained by the author. There are other forms of income such as the sale of copyrights of other works of the author, adaptation rights, etc. The money earned from selling the book did not belong to the self-funded author but to the copyright owner of the work. The author can receive royalties or other forms of economic benefits after the copyright is sold, but these income must meet the prerequisites stipulated by the law, such as the work must be sold legally. If the work was published in violation of copyright or other illegal acts, the author may lose the right to royalties or other income.