There are 4 books in the Billionaire Collection series.
The Billionaire Collection series does not have a new book coming out soon. The latest book, The Billionaire's Forbidden Little Sister (Book 4), was published in November 2019.
The first book in the Billionaire Collection series, The Billionaire Boss Next Door, was published in May 2019.
The Billionaire Collection series primarily falls into the Contemporary Romance genre.