diff --git a/internal/notification/form.go b/internal/notification/form.go
index 1a15eb5..0b8c71e 100644
--- a/internal/notification/form.go
+++ b/internal/notification/form.go
@@ -30,6 +30,7 @@ type SearchForm struct {
 	EventType string   `query:"event_type" valid:"optional"`
 	Type      string   `query:"type" valid:"optional"`
 	Recipient []string `query:"recipient" json:"recipient" valid:"optional"`
+	UserID    string   `query:"user_id" valid:"optional"`
 	Seen      *bool    `query:"seen" valid:"optional"`
 	Priority  string   `query:"priority" valid:"optional"`
 }
@@ -45,6 +46,14 @@ func (f *SearchForm) ResolvedSearch() string {
 	return ""
 }
 
+// ResolvedRecipients returns the user IDs to filter by from user_id or recipient query params.
+func (f *SearchForm) ResolvedRecipients() []string {
+	if id := strings.TrimSpace(f.UserID); id != "" {
+		return []string{id}
+	}
+	return f.Recipient
+}
+
 type NotificationListResponse struct {
 	Notifications []*NotificationResponse `json:"notifications"`
 	Meta          *response.Meta          `json:"meta"`
diff --git a/internal/notification/handler.go b/internal/notification/handler.go
index f1fc528..ea4a024 100644
--- a/internal/notification/handler.go
+++ b/internal/notification/handler.go
@@ -65,6 +65,7 @@ func (h *NotificationHandler) Send(c echo.Context) error {
 // @Param event_type query string false "Event type filter"
 // @Param type query string false "Type filter"
 // @Param recipient query string false "Recipient filter"
+// @Param user_id query string false "User ID filter"
 // @Param seen query bool false "Seen filter"
 // @Param priority query string false "Priority filter"
 // @Param limit query int false "Limit results"
diff --git a/internal/notification/service.go b/internal/notification/service.go
index 7f89a11..e14e072 100644
--- a/internal/notification/service.go
+++ b/internal/notification/service.go
@@ -197,14 +197,14 @@ func (s *notificationService) GetNotifications(ctx context.Context, req *SearchF
 		"method":     req.Method,
 		"event_type": req.EventType,
 		"type":       req.Type,
-		"recipient":  req.Recipient,
+		"recipient":  req.ResolvedRecipients(),
 		"seen":       req.Seen,
 		"priority":   req.Priority,
 		"limit":      pagination.Limit,
 		"offset":     pagination.Offset,
 	})
 
-	page, err := s.repository.GetByUserID(ctx, req.Recipient, search, req.Status, req.Seen, req.Priority, req.EventType, req.Type, pagination)
+	page, err := s.repository.GetByUserID(ctx, req.ResolvedRecipients(), search, req.Status, req.Seen, req.Priority, req.EventType, req.Type, pagination)
 	if err != nil {
 		s.logger.Error("Failed to get notifications", map[string]interface{}{
 			"error": err.Error(),