You will have to find SMS Gateway
Try these APIs
http://www.zeepmobile.com/developers/
http://www.freesmsapi.com/
https://www.tropo.com/
http://api.wadja.com/
http://www.3jam.com/api.php
http://api.smsgupshup.com/
http://www.clubtexting.com/
http://www.textmarks.com/