How can a business finds out if a mobile number is registered on KakaoTalk?

KakaoTalk is a messaging app that is widely used in South Korea. When you have a business registered in South Korea, a business can register a KakaoTalk Business Channel which will allow the business to send both notification or advertisement messages to their customers on the KakaoTalk messaging app.

When a user has given the business their mobile number, it's possible to try and send a message to the user on KakaoTalk, for example, a welcome message. If the user is not registered on KakaoTalk, it can fallback to SMS so the business will reach them in any case.

The business can also receive a delivery receipt by subscribe the callback trigger - MESSAGE DELIVERY from the Conversation API and a reason will be sent if it failed to deliver:

"reason": {
  "code": "BAD_REQUEST",
  "description": "The underlying channel reported: 3008: Phone number error",
  "sub_code": "UNSPECIFIED_SUB_CODE"
},

If an advertisement message is sent and the user is not a "friend" to the KakaoTalk Business Channel then a reason will return as below:

"reason": {
  "code": "CHANNEL_REJECT",
  "description": "The underlying channel reported: 3018: Unable to send messages (invalid or broken KakaoTalk user)",
  "sub_code": "UNSPECIFIED_SUB_CODE"
},

Learn more

• Find out more about the Sinch KakaoTalk for Business channel.
• Sinch Developer Documentation site contains comprehensive documentation and tutorials, which show you how we support KakaoTalk using the Sinch Conversation API.
• Product Information.