diff --git a/meowzip-api-server/src/main/java/com/meowzip/apiserver/cat/service/CoParentService.java b/meowzip-api-server/src/main/java/com/meowzip/apiserver/cat/service/CoParentService.java
index 52ba995..1b56b67 100644
--- a/meowzip-api-server/src/main/java/com/meowzip/apiserver/cat/service/CoParentService.java
+++ b/meowzip-api-server/src/main/java/com/meowzip/apiserver/cat/service/CoParentService.java
@@ -69,8 +69,9 @@ private boolean isMemberVisible(Member member, Cat cat, Map<Member, Boolean> coP
         return isStandBy || isNotParticipant;
     }
 
-    public Optional<CoParent> getByCoParentId(Member participant, Long coParentId) {
-        return coParentRepository.findByParticipantAndId(participant, coParentId);
+    public Optional<CoParent> getByParticipantAndCoParentId(Member receiver, Long coParentId) {
+        return coParentRepository.findByParticipantAndId(receiver, coParentId)
+                .filter(CoParent::isStandBy);
     }
 
     public boolean isResponded(Long coParentId) {
diff --git a/meowzip-api-server/src/main/java/com/meowzip/apiserver/notification/service/NotificationService.java b/meowzip-api-server/src/main/java/com/meowzip/apiserver/notification/service/NotificationService.java
index 84b1c60..0b9f065 100644
--- a/meowzip-api-server/src/main/java/com/meowzip/apiserver/notification/service/NotificationService.java
+++ b/meowzip-api-server/src/main/java/com/meowzip/apiserver/notification/service/NotificationService.java
@@ -60,14 +60,15 @@ public NotificationValidationResDTO validateNotification(Member receiver, Long n
                 .orElseThrow(() -> new ClientException.NotFound(EnumErrorCode.NOTIFICATION_HISTORY_NOT_FOUND));
 
         Long contentId = notification.getDetailLink();
-        if (contentId == null) {
+        if (!notification.isCoParentResponseNotification() && contentId == null) {
             return NotificationValidationResDTO.invalid(EnumErrorCode.BAD_REQUEST.getMessage());
         }
 
         return switch (notification.getTemplate().getCode()) {
             case MN001, MN002 -> validateCommunityPost(contentId);
             case MN003 -> validateDiary(contentId);
-            case MN004, MN005, MN006 -> validateCoParent(notification.getReceiver(), contentId);
+            case MN004 -> validateCoParentByParticipant(notification.getReceiver(), contentId);
+            case MN005, MN006 -> NotificationValidationResDTO.valid();
         };
     }
 
@@ -83,8 +84,8 @@ private NotificationValidationResDTO validateDiary(Long diaryId) {
                 : NotificationValidationResDTO.invalid(EnumErrorCode.DIARY_NOT_FOUND.getMessage());
     }
 
-    private NotificationValidationResDTO validateCoParent(Member receiver, Long coParentId) {
-        Optional<CoParent> coParent = coParentService.getByCoParentId(receiver, coParentId);
+    private NotificationValidationResDTO validateCoParentByParticipant(Member receiver, Long coParentId) {
+        Optional<CoParent> coParent = coParentService.getByParticipantAndCoParentId(receiver, coParentId);
 
         if (coParent.isEmpty()) {
             return NotificationValidationResDTO.invalid(EnumErrorCode.CO_PARENT_NOT_FOUND.getMessage());
diff --git a/meowzip-core/src/main/java/com/meowzip/notification/entity/NotificationHistory.java b/meowzip-core/src/main/java/com/meowzip/notification/entity/NotificationHistory.java
index e0da696..0b97153 100644
--- a/meowzip-core/src/main/java/com/meowzip/notification/entity/NotificationHistory.java
+++ b/meowzip-core/src/main/java/com/meowzip/notification/entity/NotificationHistory.java
@@ -68,4 +68,9 @@ public String getType() {
     public String getPushBody() {
         return this.senderNickname + this.getTitle();
     }
+
+    public boolean isCoParentResponseNotification() {
+        return this.template.getCode() == NotificationCode.MN005
+                || this.template.getCode() == NotificationCode.MN006;
+    }
 }