What is a Kakao account?
Creating a Kakao Account secures one email address you can use to explore all of Kakao's applications and linked services.
Go to More > Settings > Privacy > Kakao Account to create a Kakao account. With your Kakao account, you can restore your information including your friends list, recommended friends list, blocked friends list, hidden friends list, sent/received items, KakaoTalk ID, profile picture and status message. (Friends whose phone numbers are not saved in your contacts will be displayed under their set name.)
* NOTE : You may only use one Kakao Account per mobile number (and vice versa); you may not set more than one number to your Kakao Account. If you attempt to connect your Kakao Account to a different phone number than originally registered, you will automatically be unregistered from the account. If you have changed your phone number and had your new phone number verified, and then attempt to re-connect with your previous Kakao account, then your previous KakaoTalk will be deleted.