diff --git a/core/service.go b/core/service.go
index 2ac5725..94401e0 100644
--- a/core/service.go
+++ b/core/service.go
@@ -835,6 +835,28 @@ func (sh *serviceDescription) authorize(w http.ResponseWriter, r *http.Request)
 
 			logger.Println("session updated :", authtype, uid, session)
 
+			authInfo := sh.auths.Find(session)
+			if authInfo == nil {
+				// 잘못된 세션
+				logger.Println("authorize failed. fail to find authInfo :", session)
+				w.WriteHeader(http.StatusBadRequest)
+				return
+			}
+
+			//혹시 삭제 된 계정 아닌지 확인해본다.
+			link, err := sh.mongoClient.FindOne(CollectionLink, bson.M{
+				"platform": authtype,
+				"uid":      uid,
+			}, options.FindOne().SetProjection(bson.M{
+				"_ts": 1,
+			}))
+			if link["_ts"] != nil {
+				delts := link["_ts"].(primitive.DateTime)
+				if !delts.Time().IsZero() {
+					// 삭제된 계정. 삭제 되었다고 알려주자
+					w.Header().Add("MG-ACCOUNT-DELETED", "TRUE")
+				}
+			}
 			bt, _ := json.Marshal(output)
 			w.Write(bt)
 		} else {
@@ -887,6 +909,7 @@ func (sh *serviceDescription) delacc(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	originAuthType := sType
 	sType, sId, err := sh.getProviderInfo(sType, sId)
 	if err != nil {
 		logger.Error("delacc failed. getProviderInfo err :", err)
@@ -924,7 +947,7 @@ func (sh *serviceDescription) delacc(w http.ResponseWriter, r *http.Request) {
 			"$set": primitive.M{"_ts": curtime},
 		}
 
-		if sType == AuthPlatformFirebaseAuth {
+		if originAuthType == AuthPlatformFirebaseAuth {
 			sh.mongoClient.Delete(CollectionFirebaseUserInfo, bson.M{
 				"firebaseuserid": sId,
 			})