The iPhone Contacts Backup program is the best tool for your to sync SCV contacts to iPhone. Import CSV contact files to iPhone 6 Plus/6/5S/5/4S/4/3GS now:
(for Windows:) https://www.all-iphone-data-recovery.com/fonetrans
(for Mac:) https://www.all-iphone-data-recovery.com/fonetrans-mac
Still worry about how can be a CSV file directly loaded into an iPhone 6+/6/5S/5C/5/4S/4/3GS? Don’t worry now. A professional iPhone contacts backup program is just here to receive the CSV contact list and then synchronize with the iPhone for you.
Watch the video tutorial and download the free trial version of Aiseesoft FoneTrans (formly named XiliSoft iPhone Contacts Backup tool) to import/export CSV contacts file to iPhone with just one click.