ACX stands for Audiobook Creation Exchange, which is a marketplace owned by Audible Inc., an Amazon company, that connects professional narrators, authors, agents, publishers, and rights holders to create and distribute audiobooks. ACX allows authors, literary agents, publishers, and other rights holders to post audiobook rights to both new frontlist titles and to backlist titles that were never published as audiobooks. On ACX, a producer is anyone who can deliver or help deliver a retail-ready audiobook, including recording studios, narrators, audio engineers, and audiobook editors. Rights holders include anyone who owns the audio rights to a book, such as authors, narrators, literary agents, and publishers.

ACX offers two royalty models for rights holders: exclusive and non-exclusive distribution rights. With exclusive distribution rights, ACX has the exclusive right to distribute the audiobook, and the rights holder earns 40% of retail sales on Audible, Amazon, and iTunes. With non-exclusive distribution rights, the rights holder retains the right to distribute the audiobook elsewhere, and earns 25% of retail sales on Audible, Amazon, and iTunes. ACX also offers a pay-for-production model, where the rights holder pays a one-time fee to produce the audiobook.

ACX is currently open to residents of the United States, United Kingdom, Canada, and Ireland who have a mailing address, valid local Taxpayer Identification Number (TIN), and banking details for one of these countries. ACX authors and publishers can earn between 20%-40% of their title royalties through ACX, depending on the distribution option they select and the method.