diff --git a/wai-server/core/handler/whatsappHandler.js b/wai-server/core/handler/whatsappHandler.js
index 42cb78b..a36047c 100644
--- a/wai-server/core/handler/whatsappHandler.js
+++ b/wai-server/core/handler/whatsappHandler.js
@@ -24,8 +24,9 @@ const timeField = { saved: 'createTime', pending: 'createTime', sent: 'sendTime'
 const statusMapped = { saved: 'accepted', pending: 'accepted', sent: 'sent', delivered: 'delivered', read: 'read', failed: 'failed' };
 const directionField = { 'message:received': 'inbound', 'message:updated': 'outbound' };
 const directionPrefix = { inbound: 'in_', outbound: 'out_' };
+const directionIdUserPrefix = { inbound: 'to', outbound: 'from' };
 
-const uniqueMsgId = msg => (msg.id && msg.direction ? `${directionPrefix[msg.direction]}${msg.to.replace('+', '')}_${msg.id}` : undefined);
+const uniqueMsgId = msg => (msg.id && msg.direction ? `${directionPrefix[msg.direction]}${msg[directionIdUserPrefix[msg.direction]].replace('+', '')}_${msg.id}` : undefined);
 
 /**
  * @returns {Object} webhookBody