If you purchased ePub books on
Kobo books, Adobe, Sony Store or other eBook stores, they may be protected by DRM. And at the same time, you got a
iPhone. So you may wanna read ePub on your iPhone. But it doesn't work. Well, to read ePub on your iPhone, you need to remove DRM from ePub.
Using
Calibre plug-ins is the easiest way to remove DRM from ePub files. This method works fine with most ePub ebooks. But please note that it doesn't work with
iBookstore ePub ebooks, because they Apple doesn't use standard ePub ebooks.
You may download DRM removal plug-ins for Calibre from the
DRM Tools Archive.
After removing DRM from ePub ebooks, drag-n-drop them onto iTunes, and then sync your iPhone with the iTunes.
Note that there are some commercial ePub DRM removal tools, which use the Calibre DRM removal plugins illegally. Don't buy software that is free!