Comma-separated values (CSV) files are one of the many file types used to save contact information. Once you've exported your contacts to a CSV file, how you upload it to your smartphone depends on your type of phone. While some phones make it easy to upload your CSV file, others may require some workarounds.
Cloud Tools
A multi-platform solution for syncing your CSV contacts to your phone is to upload it to a cloud service and sync that service to your phone. This has the added benefit of maintaining up-to-date contact information on multiple devices, even after you've made changes on your phone. You can use Google's contact services to sync contacts to multiple smartphones, including the iPhone and Android systems. Soocial is an alternative contact management service.
iPhone
The iPhone doesn't have any sort of import utility for CSV files -- not on the phone itself, not in iTunes and not even in iCloud. You can import your CSV files into either Outlook or Address Book, and then use the iCloud desktop client to sync contacts to your iPhone. You can also set your iPhone to sync with Google Contacts, which supports CSV importing. You can import vCard files directly into iCloud, if you have a method of exporting (or converting) all of your contacts to a vCard file.
Android
The most efficient method for syncing contacts is to add them to your linked Google account - you can do this at google.com/contacts. Import your contacts by clicking the "More" button and selecting "Import." While Android has a feature for importing contacts to your phone from the SD card, it uses vCard files, not CSV files.
BlackBerry
To import your CSV contacts to your BlackBerry, you'll need to connect to a computer with the BlackBerry Desktop Software installed on it. However, the option to import CSV files -- the ASCII Importer/Exporter - was removed from version 7 of the software. For the CSV file import to work, it'll need to use the same fields as the BlackBerry contact system. If it does not work, the software used to create the CSV file may not be compatible with your BlackBerry.