Read PDF documents in Books on iPhone
In the Books app , you can open and save PDFs that you receive in Mail, Messages, and other apps.
Open PDFs in Books
Do one of the following:
Touch and hold the PDF attachment, then tap Copy to Books.
Tap the PDF attachment to open it, tap , then tap Copy to Books.
Email or print a PDF document
Open the PDF document, tap , then choose Mail or Print.
See About AirPrint.
Mark up a PDF
Open the PDF and tap to use the drawing and annotation tools (tap near the center of a page if you don’t see ).
Sync PDFs across devices
You can sync PDFs and books that are not from the Book Store across your iOS devices where you are signed in with the same Apple ID. Go to Settings > [your name] > iCloud, turn on iCloud Drive, then turn on Books. Then go to Settings > Books, and turn on iCloud Drive.