diff --git a/backend/internal/service/tenant_service.go b/backend/internal/service/tenant_service.go
index 6a3a3e8a..0e16890d 100644
--- a/backend/internal/service/tenant_service.go
+++ b/backend/internal/service/tenant_service.go
@@ -112,51 +112,6 @@ func (s *tenantService) RegisterTenant(ctx context.Context, name, slug, tenantTy
 		return nil, err
 	}
 
-	// [New] Create Default User Groups
-	if s.userGroupRepo != nil {
-		groups := []struct {
-			Name string
-			Slug string
-		}{
-			{Name: "임직원", Slug: "members"},
-			{Name: "관리자", Slug: "admins"},
-		}
-
-		for _, g := range groups {
-			newGroup := &domain.UserGroup{
-				TenantID:    tenant.ID,
-				Name:        g.Name,
-				Slug:        g.Slug,
-				Description: tenant.Name + " " + g.Name + " 그룹",
-			}
-			if err := s.userGroupRepo.Create(ctx, newGroup); err == nil {
-				// Sync group to Keto via Outbox
-				if s.outboxRepo != nil {
-					_ = s.outboxRepo.Create(ctx, &domain.KetoOutbox{
-						Namespace: "Tenant",
-						Object:    newGroup.ID,
-						Relation:  "parents",
-						Subject:   "Tenant:" + tenant.ID,
-						Action:    domain.KetoOutboxActionCreate,
-					})
-					
-					// If this is the 'admins' group and we have a creatorID, add creator to this group
-					if g.Slug == "admins" && creatorID != "" {
-						_ = s.outboxRepo.Create(ctx, &domain.KetoOutbox{
-							Namespace: "Tenant",
-							Object:    newGroup.ID,
-							Relation:  "owners",
-							Subject:   "User:" + creatorID,
-							Action:    domain.KetoOutboxActionCreate,
-						})
-					}
-				}
-			} else {
-				slog.Error("Failed to create default group", "group", g.Slug, "tenant", tenant.ID, "error", err)
-			}
-		}
-	}
-
 	// [Keto] Sync hierarchy and ownership via Outbox
 	if s.outboxRepo != nil {
 		// Sync hierarchy
@@ -256,37 +211,6 @@ func (s *tenantService) ApproveTenant(ctx context.Context, id string) error {
 		return err
 	}
 
-	// [New] Create Default User Groups upon approval
-	if s.userGroupRepo != nil {
-		groups := []struct {
-			Name string
-			Slug string
-		}{
-			{Name: "임직원", Slug: "members"},
-			{Name: "관리자", Slug: "admins"},
-		}
-
-		for _, g := range groups {
-			newGroup := &domain.UserGroup{
-				TenantID:    tenant.ID,
-				Name:        g.Name,
-				Slug:        g.Slug,
-				Description: tenant.Name + " " + g.Name + " 그룹",
-			}
-			if err := s.userGroupRepo.Create(ctx, newGroup); err == nil {
-				if s.outboxRepo != nil {
-					_ = s.outboxRepo.Create(ctx, &domain.KetoOutbox{
-						Namespace: "Tenant",
-						Object:    newGroup.ID,
-						Relation:  "parents",
-						Subject:   "Tenant:" + tenant.ID,
-						Action:    domain.KetoOutboxActionCreate,
-					})
-				}
-			}
-		}
-	}
-
 	// [Keto] Sync relation via Outbox
 	if s.outboxRepo != nil {
 		if adminEmail, ok := tenant.Config["adminEmail"].(string); ok && adminEmail != "" {