diff --git a/src/main/java/com/eactive/eai/rms/onl/apim/approval/credential/CredentialService.java b/src/main/java/com/eactive/eai/rms/onl/apim/approval/credential/CredentialService.java
index 0f8a42f..27ab9b5 100644
--- a/src/main/java/com/eactive/eai/rms/onl/apim/approval/credential/CredentialService.java
+++ b/src/main/java/com/eactive/eai/rms/onl/apim/approval/credential/CredentialService.java
@@ -29,4 +29,18 @@ public class CredentialService extends AbstractDataService<Credential, String, C
 
         return repository.findAll(predicate, pageable);
     }
+
+    /**
+     * clientId와 orgId로 Credential 조회
+     *
+     * @param clientId 클라이언트 ID
+     * @param orgId 조직 ID
+     * @return Credential 또는 null
+     */
+    public Credential findByClientidAndOrgid(String clientId, String orgId) {
+        QCredential qCredential = QCredential.credential;
+        BooleanExpression predicate = qCredential.clientid.eq(clientId)
+                .and(qCredential.orgid.eq(orgId));
+        return repository.findOne(predicate).orElse(null);
+    }
 }
diff --git a/src/main/java/com/eactive/eai/rms/onl/manage/authserver/client/ClientManService.java b/src/main/java/com/eactive/eai/rms/onl/manage/authserver/client/ClientManService.java
index 8e2f2bc..4557ab9 100644
--- a/src/main/java/com/eactive/eai/rms/onl/manage/authserver/client/ClientManService.java
+++ b/src/main/java/com/eactive/eai/rms/onl/manage/authserver/client/ClientManService.java
@@ -26,10 +26,10 @@ import com.eactive.eai.rms.common.base.OnlBaseService;
 import com.eactive.eai.rms.data.entity.onl.authserver.ClientEntityService;
 import com.eactive.eai.rms.data.entity.onl.authserver.ClientSearch;
 
+import java.time.format.DateTimeFormatter;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
-import java.util.Optional;
 import java.util.stream.Collectors;
 
 @Service
@@ -167,19 +167,15 @@ public class ClientManService extends OnlBaseService {
 			DataSourceContextHolder.setDataSourceType(monitoringType);
 
 			// 5. 기존 Credential 확인
-			Optional<Credential> existingCredential = credentialService.getRepository()
-					.findOne((root, query, cb) -> cb.and(
-							cb.equal(root.get("clientid"), clientId),
-							cb.equal(root.get("orgid"), orgId)
-					));
+			Credential existingCredential = credentialService.findByClientidAndOrgid(clientId, orgId);
 
 			// 6. 데이터 변환 (ClientEntity → CredentialUI)
 			CredentialUI credentialUI = convertToCredentialUI(clientEntity);
 
 			SyncResult.SyncAction action;
-			if (existingCredential.isPresent()) {
+			if (existingCredential != null) {
 				// 업데이트: 기존 값 유지해야 할 필드 처리
-				Credential existing = existingCredential.get();
+				Credential existing = existingCredential;
 				if (StringUtils.isNotBlank(existing.getAppDescription())) {
 					credentialUI.setAppDescription(existing.getAppDescription());
 				}
@@ -258,7 +254,9 @@ public class ClientManService extends OnlBaseService {
 
 		// 수정 정보
 		credentialUI.setModifiedby(clientEntity.getModifiedby());
-		credentialUI.setModifiedon(clientEntity.getModifiedon());
+		if (clientEntity.getModifiedon() != null) {
+			credentialUI.setModifiedon(clientEntity.getModifiedon().format(DateTimeFormatter.ofPattern("yyyyMMddHHmmss")));
+		}
 
 		// API 목록 변환
 		List<ApiSpecInfoUI> apiList = new ArrayList<>();