How do I permanently delete books from Audible?

Answer
  1. Go to Manage Your Content and Devices page on Amazon.
  2. Next to “Show”, click the Books button and then select Audiobooks.
  3. Choose the audiobook you want to delete and click the checkbox next to it.
  4. Click followed by Yes, delete permanently.

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How do I delete audiobooks from my iPhone?

You can delete downloaded books and more from within the Apple Books app or audiobooks from the Settings app.
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From the Settings app
  1. Open the Settings app.
  2. Tap General, then tap iPhone Storage or iPad Storage.
  3. Scroll to Books, then tap it.
  4. Swipe left on any audiobook download and tap Delete.