diff --git a/adminfront/src/lib/tenantTree.test.ts b/adminfront/src/lib/tenantTree.test.ts
index eb277ce7..7cdf148c 100644
--- a/adminfront/src/lib/tenantTree.test.ts
+++ b/adminfront/src/lib/tenantTree.test.ts
@@ -44,18 +44,18 @@ describe("tenantTree utility", () => {
 
   it("calculates recursive member counts correctly", () => {
     const { currentBase } = buildTenantFullTree(mockTenants, "root-1");
-    
+
     expect(currentBase).not.toBeNull();
     if (currentBase) {
       // Direct: 10, Child: 5, Grandchild: 2 -> Total: 17
       expect(currentBase.recursiveMemberCount).toBe(17);
       expect(currentBase.children).toHaveLength(1);
-      
+
       const child = currentBase.children[0];
       // Direct: 5, Grandchild: 2 -> Total: 7
       expect(child.recursiveMemberCount).toBe(7);
       expect(child.children).toHaveLength(1);
-      
+
       const grandchild = child.children[0];
       // Direct: 2 -> Total: 2
       expect(grandchild.recursiveMemberCount).toBe(2);
@@ -84,10 +84,10 @@ describe("tenantTree utility", () => {
         updatedAt: "",
       },
     ];
-    
+
     const { subTree } = buildTenantFullTree(multiRootTenants);
     expect(subTree).toHaveLength(2);
-    expect(subTree.map(n => n.id)).toContain("root-1");
-    expect(subTree.map(n => n.id)).toContain("root-2");
+    expect(subTree.map((n) => n.id)).toContain("root-1");
+    expect(subTree.map((n) => n.id)).toContain("root-2");
   });
 });
diff --git a/adminfront/tests/auth.spec.ts b/adminfront/tests/auth.spec.ts
index fff2875e..46daaaa8 100644
--- a/adminfront/tests/auth.spec.ts
+++ b/adminfront/tests/auth.spec.ts
@@ -55,7 +55,7 @@ test.describe("Authentication", () => {
 
     // Should be on the dashboard/overview
     await expect(page.locator("aside")).toBeVisible();
-    await expect(page.locator("h1")).toContainText("Admin Control");
+    await expect(page.locator("h1")).toContainText(/Admin Control|운영 도구/);
   });
 
   test("should logout and redirect to login page", async ({ page }) => {
diff --git a/adminfront/tests/tenants.spec.ts b/adminfront/tests/tenants.spec.ts
index 253e1b76..e2fbb624 100644
--- a/adminfront/tests/tenants.spec.ts
+++ b/adminfront/tests/tenants.spec.ts
@@ -170,31 +170,45 @@ test.describe("Tenants Management", () => {
     const parentRow = page.locator("tr", { hasText: "Parent Org" });
     await expect(parentRow).toContainText("5"); // Direct
     await expect(parentRow).toContainText("8"); // Total (5 + 3)
-    
+
     // Check for either English or Korean labels
-    const hasDirectLabel = await parentRow.evaluate(el => 
-      el.textContent?.includes("Direct") || el.textContent?.includes("소속")
+    const hasDirectLabel = await parentRow.evaluate(
+      (el) =>
+        el.textContent?.includes("Direct") || el.textContent?.includes("소속"),
     );
-    const hasTotalLabel = await parentRow.evaluate(el => 
-      el.textContent?.includes("Total") || el.textContent?.includes("전체")
+    const hasTotalLabel = await parentRow.evaluate(
+      (el) =>
+        el.textContent?.includes("Total") || el.textContent?.includes("전체"),
     );
     expect(hasDirectLabel).toBe(true);
     expect(hasTotalLabel).toBe(true);
 
     // Open Member List Dialog - Click the members count button
-    const memberButton = parentRow.getByRole("button").filter({ hasText: /Direct|소속/ });
+    const memberButton = parentRow
+      .getByRole("button")
+      .filter({ hasText: /Direct|소속/ });
     await memberButton.click();
-    
+
     // Check Tabs in Member List Dialog
     // Use regex to match either language, ignoring the count suffix
-    await expect(page.locator('button[role="tab"]').filter({ hasText: /소속 멤버|Direct Members/ })).toBeVisible();
-    await expect(page.locator('button[role="tab"]').filter({ hasText: /하위 조직 멤버|Descendant Members/ })).toBeVisible();
+    await expect(
+      page
+        .locator('button[role="tab"]')
+        .filter({ hasText: /소속 멤버|Direct Members/ }),
+    ).toBeVisible();
+    await expect(
+      page
+        .locator('button[role="tab"]')
+        .filter({ hasText: /하위 조직 멤버|Descendant Members/ }),
+    ).toBeVisible();
 
     // Direct Members Tab should show parent's user
     await expect(page.locator("role=dialog")).toContainText("u1@parent.com");
 
     // Switch to Descendant Members Tab
-    await page.click('button[role="tab"]:has-text("하위 조직 멤버"), button[role="tab"]:has-text("Descendant Members")');
+    await page.click(
+      'button[role="tab"]:has-text("하위 조직 멤버"), button[role="tab"]:has-text("Descendant Members")',
+    );
     await expect(page.locator("role=dialog")).toContainText("u2@child.com");
   });
 });
diff --git a/backend/internal/domain/user.go b/backend/internal/domain/user.go
index a5b9b794..6a27ed2d 100644
--- a/backend/internal/domain/user.go
+++ b/backend/internal/domain/user.go
@@ -29,7 +29,7 @@ type User struct {
 	Tenant          *Tenant        `gorm:"foreignKey:TenantID" json:"tenant,omitempty"`
 	RelyingPartyID  *string        `gorm:"column:relying_party_id;type:uuid;index" json:"relyingPartyId,omitempty"` // RP Admin용
 	Department      string         `gorm:"column:department" json:"department"`
-	Position        string         `gorm:"column:position" json:"position"` // 직급 (예: 수석, 책임, 선임)
+	Position        string         `gorm:"column:position" json:"position"`  // 직급 (예: 수석, 책임, 선임)
 	JobTitle        string         `gorm:"column:job_title" json:"jobTitle"` // 직무 (예: 프론트엔드 개발, 기획)
 	Metadata        JSONMap        `gorm:"column:metadata;type:jsonb" json:"metadata,omitempty"`
 	Status          string         `gorm:"column:status;default:'active'" json:"status"`
diff --git a/backend/internal/handler/auth_handler_async_test.go b/backend/internal/handler/auth_handler_async_test.go
index 3a7ed64c..35c13cf3 100644
--- a/backend/internal/handler/auth_handler_async_test.go
+++ b/backend/internal/handler/auth_handler_async_test.go
@@ -98,7 +98,7 @@ func (m *AsyncMockUserRepo) ListByTenant(ctx context.Context, tenantID string) (
 	return nil, nil
 }
 
-func (m *AsyncMockUserRepo) List(ctx context.Context, offset, limit int, search string) ([]domain.User, int64, error) {
+func (m *AsyncMockUserRepo) List(ctx context.Context, offset, limit int, search string, companyCode string) ([]domain.User, int64, error) {
 	return nil, 0, nil
 }
 
@@ -110,6 +110,9 @@ func (m *AsyncMockUserRepo) CountByTenantIDs(ctx context.Context, tenantIDs []st
 	return nil, nil
 }
 
+func (m *AsyncMockUserRepo) CountByCompanyCodes(ctx context.Context, codes []string) (map[string]int64, error) {
+	return nil, nil
+}
 
 type AsyncMockRedisRepo struct {
 	mock.Mock
@@ -161,6 +164,10 @@ func (m *AsyncMockTenantService) GetTenant(ctx context.Context, id string) (*dom
 	return nil, nil
 }
 
+func (m *AsyncMockTenantService) ListTenants(ctx context.Context, limit, offset int, parentID string) ([]domain.Tenant, int64, error) {
+	return nil, 0, nil
+}
+
 func (m *AsyncMockTenantService) ListManageableTenants(ctx context.Context, userID string) ([]domain.Tenant, error) {
 	return nil, nil
 }
diff --git a/backend/internal/handler/tenant_handler.go b/backend/internal/handler/tenant_handler.go
index c758a021..ac6ec510 100644
--- a/backend/internal/handler/tenant_handler.go
+++ b/backend/internal/handler/tenant_handler.go
@@ -98,10 +98,6 @@ func (h *TenantHandler) ApproveTenant(c *fiber.Ctx) error {
 }
 
 func (h *TenantHandler) ListTenants(c *fiber.Ctx) error {
-	if h.DB == nil {
-		return c.Status(fiber.StatusServiceUnavailable).JSON(fiber.Map{"error": "database not available"})
-	}
-
 	limit := c.QueryInt("limit", 50)
 	offset := c.QueryInt("offset", 0)
 	parentId := c.Query("parentId")
@@ -113,24 +109,8 @@ func (h *TenantHandler) ListTenants(c *fiber.Ctx) error {
 		offset = 0
 	}
 
-	// Use separate queries for count and find to avoid GORM statement contamination
-	countQuery := h.DB.Model(&domain.Tenant{})
-	if parentId != "" {
-		countQuery = countQuery.Where("parent_id = ?", parentId)
-	}
-
-	var total int64
-	if err := countQuery.Count(&total).Error; err != nil {
-		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": err.Error()})
-	}
-
-	findQuery := h.DB.Model(&domain.Tenant{})
-	if parentId != "" {
-		findQuery = findQuery.Where("parent_id = ?", parentId)
-	}
-
-	var tenants []domain.Tenant
-	if err := findQuery.Order("created_at desc").Limit(limit).Offset(offset).Preload("Domains").Find(&tenants).Error; err != nil {
+	tenants, total, err := h.Service.ListTenants(c.Context(), limit, offset, parentId)
+	if err != nil {
 		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": err.Error()})
 	}
 
diff --git a/backend/internal/handler/tenant_handler_test.go b/backend/internal/handler/tenant_handler_test.go
index b15b4a65..54285177 100644
--- a/backend/internal/handler/tenant_handler_test.go
+++ b/backend/internal/handler/tenant_handler_test.go
@@ -66,10 +66,51 @@ func (m *MockTenantService) GetTenant(ctx context.Context, id string) (*domain.T
 	return args.Get(0).(*domain.Tenant), args.Error(1)
 }
 
+func (m *MockTenantService) ListTenants(ctx context.Context, limit, offset int, parentID string) ([]domain.Tenant, int64, error) {
+	args := m.Called(ctx, limit, offset, parentID)
+	return args.Get(0).([]domain.Tenant), args.Get(1).(int64), args.Error(2)
+}
+
 func (m *MockTenantService) SetKetoService(keto service.KetoService) {
 	m.Called(keto)
 }
 
+type MockUserRepoForHandler struct {
+	mock.Mock
+}
+
+func (m *MockUserRepoForHandler) Create(ctx context.Context, user *domain.User) error { return nil }
+func (m *MockUserRepoForHandler) Update(ctx context.Context, user *domain.User) error { return nil }
+func (m *MockUserRepoForHandler) Delete(ctx context.Context, id string) error         { return nil }
+func (m *MockUserRepoForHandler) FindByEmail(ctx context.Context, email string) (*domain.User, error) {
+	return nil, nil
+}
+func (m *MockUserRepoForHandler) FindByID(ctx context.Context, id string) (*domain.User, error) {
+	return nil, nil
+}
+func (m *MockUserRepoForHandler) FindByIDs(ctx context.Context, ids []string) ([]domain.User, error) {
+	return nil, nil
+}
+func (m *MockUserRepoForHandler) ListByTenant(ctx context.Context, tenantID string) ([]domain.User, error) {
+	return nil, nil
+}
+func (m *MockUserRepoForHandler) List(ctx context.Context, offset, limit int, search string, companyCode string) ([]domain.User, int64, error) {
+	return nil, 0, nil
+}
+func (m *MockUserRepoForHandler) CountByTenant(ctx context.Context, tenantID string) (int64, error) {
+	return 0, nil
+}
+func (m *MockUserRepoForHandler) CountByTenantIDs(ctx context.Context, tenantIDs []string) (map[string]int64, error) {
+	return nil, nil
+}
+func (m *MockUserRepoForHandler) CountByCompanyCodes(ctx context.Context, codes []string) (map[string]int64, error) {
+	args := m.Called(ctx, codes)
+	if args.Get(0) == nil {
+		return nil, args.Error(1)
+	}
+	return args.Get(0).(map[string]int64), args.Error(1)
+}
+
 func TestTenantHandler_CreateTenant(t *testing.T) {
 	app := fiber.New()
 	mockSvc := new(MockTenantService)
@@ -98,6 +139,47 @@ func TestTenantHandler_CreateTenant(t *testing.T) {
 	assert.Equal(t, "t1", got["id"])
 }
 
+func TestTenantHandler_ListTenants(t *testing.T) {
+	app := fiber.New()
+	mockSvc := new(MockTenantService)
+	mockUserRepo := new(MockUserRepoForHandler)
+
+	h := &TenantHandler{
+		Service:  mockSvc,
+		UserRepo: mockUserRepo,
+	}
+
+	app.Get("/tenants", h.ListTenants)
+
+	tenants := []domain.Tenant{
+		{ID: "t1", Name: "Tenant A", Slug: "slug-a"},
+		{ID: "t2", Name: "Tenant B", Slug: "slug-b"},
+	}
+	mockSvc.On("ListTenants", mock.Anything, 10, 0, "").Return(tenants, int64(2), nil)
+	mockUserRepo.On("CountByCompanyCodes", mock.Anything, []string{"slug-a", "slug-b"}).
+		Return(map[string]int64{"slug-a": 5, "slug-b": 10}, nil)
+
+	req := httptest.NewRequest("GET", "/tenants?limit=10&offset=0", nil)
+	resp, _ := app.Test(req)
+
+	assert.Equal(t, http.StatusOK, resp.StatusCode)
+
+	var res tenantListResponse
+	json.NewDecoder(resp.Body).Decode(&res)
+
+	assert.Equal(t, int64(2), res.Total)
+	assert.Len(t, res.Items, 2)
+
+	// Check if counts are mapped correctly
+	for _, item := range res.Items {
+		if item.Slug == "slug-a" {
+			assert.Equal(t, int64(5), item.MemberCount)
+		} else if item.Slug == "slug-b" {
+			assert.Equal(t, int64(10), item.MemberCount)
+		}
+	}
+}
+
 func TestTenantHandler_ApproveTenant(t *testing.T) {
 	app := fiber.New()
 	mockSvc := new(MockTenantService)
diff --git a/backend/internal/handler/user_handler.go b/backend/internal/handler/user_handler.go
index 6b2d8be5..5864852d 100644
--- a/backend/internal/handler/user_handler.go
+++ b/backend/internal/handler/user_handler.go
@@ -322,12 +322,12 @@ func (h *UserHandler) CreateUser(c *fiber.Ctx) error {
 	// [New] Local DB Sync - Ensure user exists in read-model
 	if h.UserRepo != nil {
 		localUser := h.mapToLocalUser(*identity)
-		
+
 		// Sync to local DB
 		go func(u *domain.User, role string, tID *string) {
 			ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
 			defer cancel()
-			
+
 			// Use Update (upsert) instead of Create for robustness
 			if err := h.UserRepo.Update(ctx, u); err != nil {
 				slog.Error("[UserHandler] Failed to sync new user to local DB", "email", u.Email, "error", err)
@@ -475,14 +475,14 @@ func (h *UserHandler) UpdateUser(c *fiber.Ctx) error {
 	// [New] Local DB Sync - Sync synchronously to ensure immediate consistency for the caller
 	if h.UserRepo != nil {
 		updatedLocalUser := h.mapToLocalUser(*updated)
-		
+
 		ctx := context.Background() // Use request context if appropriate, but sync must finish
 		if err := h.UserRepo.Update(ctx, updatedLocalUser); err != nil {
 			slog.Error("[UserHandler] Failed to sync updated user to local DB", "userID", updatedLocalUser.ID, "error", err)
 		}
 
 		// [Keto Sync] asynchronously as it's less critical for immediate UI count
-		go h.syncKetoRole(context.Background(), updatedLocalUser.ID, 
+		go h.syncKetoRole(context.Background(), updatedLocalUser.ID,
 			extractTraitString(updated.Traits, "grade"), oldRole, oldTenantID, updatedLocalUser.TenantID)
 	}
 
diff --git a/backend/internal/repository/tenant_repository.go b/backend/internal/repository/tenant_repository.go
index cc20a6b5..9a18c4fe 100644
--- a/backend/internal/repository/tenant_repository.go
+++ b/backend/internal/repository/tenant_repository.go
@@ -16,6 +16,7 @@ type TenantRepository interface {
 	FindByDomain(ctx context.Context, domainName string) (*domain.Tenant, error)
 	FindByIDs(ctx context.Context, ids []string) ([]domain.Tenant, error)
 	AddDomain(ctx context.Context, tenantID string, domainName string, verified bool) error
+	List(ctx context.Context, limit, offset int, parentID string) ([]domain.Tenant, int64, error)
 }
 
 type tenantRepository struct {
@@ -90,3 +91,23 @@ func (r *tenantRepository) AddDomain(ctx context.Context, tenantID string, domai
 	}
 	return r.db.WithContext(ctx).Create(&td).Error
 }
+
+func (r *tenantRepository) List(ctx context.Context, limit, offset int, parentID string) ([]domain.Tenant, int64, error) {
+	var tenants []domain.Tenant
+	var total int64
+	db := r.db.WithContext(ctx).Model(&domain.Tenant{})
+
+	if parentID != "" {
+		db = db.Where("parent_id = ?", parentID)
+	}
+
+	if err := db.Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+
+	if err := db.Order("created_at desc").Limit(limit).Offset(offset).Preload("Domains").Find(&tenants).Error; err != nil {
+		return nil, 0, err
+	}
+
+	return tenants, total, nil
+}
diff --git a/backend/internal/repository/user_repository.go b/backend/internal/repository/user_repository.go
index 543a1697..b793aa6f 100644
--- a/backend/internal/repository/user_repository.go
+++ b/backend/internal/repository/user_repository.go
@@ -119,10 +119,10 @@ func (r *userRepository) CountByCompanyCodes(ctx context.Context, codes []string
 	// 1. Resolve IDs for these codes to support dual counting (slug or ID)
 	var tenants []domain.Tenant
 	_ = r.db.WithContext(ctx).Where("slug IN ?", codes).Find(&tenants).Error
-	
+
 	idToSlug := make(map[string]string)
 	slugToNormalized := make(map[string]string)
-	
+
 	for _, code := range codes {
 		slugToNormalized[strings.ToLower(strings.TrimSpace(code))] = code
 	}
@@ -156,13 +156,13 @@ func (r *userRepository) CountByCompanyCodes(ctx context.Context, codes []string
 		} else if res.TenantID != "" {
 			slug = idToSlug[res.TenantID]
 		}
-		
+
 		if slug != "" {
 			normalizedSlug := strings.ToLower(strings.TrimSpace(slug))
 			counts[normalizedSlug] += res.Count
 		}
 	}
-	
+
 	return counts, nil
 }
 
diff --git a/backend/internal/repository/user_repository_test.go b/backend/internal/repository/user_repository_test.go
index 886f297d..7d8d421e 100644
--- a/backend/internal/repository/user_repository_test.go
+++ b/backend/internal/repository/user_repository_test.go
@@ -56,7 +56,7 @@ func TestUserRepository(t *testing.T) {
 		_ = repo.Create(ctx, &domain.User{Email: "alice@test.com", Name: "Alice", Role: "user"})
 		_ = repo.Create(ctx, &domain.User{Email: "bob@test.com", Name: "Bob", Role: "user"})
 
-		users, total, err := repo.List(ctx, 0, 10, "Alice")
+		users, total, err := repo.List(ctx, 0, 10, "Alice", "")
 		assert.NoError(t, err)
 		assert.True(t, total >= 1)
 		assert.Equal(t, "Alice", users[0].Name)
@@ -73,4 +73,25 @@ func TestUserRepository(t *testing.T) {
 		assert.Error(t, err) // Should not be found
 		assert.Nil(t, found)
 	})
+
+	t.Run("CountByCompanyCodes", func(t *testing.T) {
+		// Clean start for this subtest
+		testDB.Exec("DELETE FROM users")
+
+		users := []domain.User{
+			{Email: "u1@a.com", Name: "U1", CompanyCode: "tenant-a"},
+			{Email: "u2@a.com", Name: "U2", CompanyCode: "tenant-a"},
+			{Email: "u3@b.com", Name: "U3", CompanyCode: "tenant-b"},
+			{Email: "u4@none.com", Name: "U4", CompanyCode: ""},
+		}
+		for _, u := range users {
+			_ = repo.Create(ctx, &u)
+		}
+
+		counts, err := repo.CountByCompanyCodes(ctx, []string{"tenant-a", "tenant-b", "tenant-c"})
+		assert.NoError(t, err)
+		assert.Equal(t, int64(2), counts["tenant-a"])
+		assert.Equal(t, int64(1), counts["tenant-b"])
+		assert.Equal(t, int64(0), counts["tenant-c"])
+	})
 }
diff --git a/backend/internal/service/tenant_service.go b/backend/internal/service/tenant_service.go
index 2f358ec5..c1c161a5 100644
--- a/backend/internal/service/tenant_service.go
+++ b/backend/internal/service/tenant_service.go
@@ -18,6 +18,7 @@ type TenantService interface {
 	GetTenantByDomain(ctx context.Context, emailDomain string) (*domain.Tenant, error)
 	GetTenantBySlug(ctx context.Context, slug string) (*domain.Tenant, error)
 	GetTenant(ctx context.Context, id string) (*domain.Tenant, error)
+	ListTenants(ctx context.Context, limit, offset int, parentID string) ([]domain.Tenant, int64, error)
 	ApproveTenant(ctx context.Context, id string) error
 	SetKetoService(keto KetoService) // 추가
 }
@@ -226,3 +227,8 @@ func (s *tenantService) GetTenantByDomain(ctx context.Context, emailDomain strin
 func (s *tenantService) GetTenantBySlug(ctx context.Context, slug string) (*domain.Tenant, error) {
 	return s.repo.FindBySlug(ctx, slug)
 }
+
+func (s *tenantService) ListTenants(ctx context.Context, limit, offset int, parentID string) ([]domain.Tenant, int64, error) {
+	// Let the repository handle the query and pagination
+	return s.repo.List(ctx, limit, offset, parentID)
+}
diff --git a/backend/internal/service/tenant_service_test.go b/backend/internal/service/tenant_service_test.go
index 2216ffdb..2952bfe8 100644
--- a/backend/internal/service/tenant_service_test.go
+++ b/backend/internal/service/tenant_service_test.go
@@ -59,6 +59,11 @@ func (m *MockTenantRepoForSvc) AddDomain(ctx context.Context, tenantID string, d
 	return m.Called(ctx, tenantID, domainName, verified).Error(0)
 }
 
+func (m *MockTenantRepoForSvc) List(ctx context.Context, limit, offset int, parentID string) ([]domain.Tenant, int64, error) {
+	args := m.Called(ctx, limit, offset, parentID)
+	return args.Get(0).([]domain.Tenant), int64(args.Int(1)), args.Error(2)
+}
+
 type MockKetoSvcForTenant struct {
 	mock.Mock
 }
@@ -116,7 +121,7 @@ func (m *MockUserRepoForTenant) ListByTenant(ctx context.Context, tenantID strin
 	return nil, nil
 }
 
-func (m *MockUserRepoForTenant) List(ctx context.Context, offset, limit int, search string) ([]domain.User, int64, error) {
+func (m *MockUserRepoForTenant) List(ctx context.Context, offset, limit int, search string, companyCode string) ([]domain.User, int64, error) {
 	return nil, 0, nil
 }
 
@@ -133,7 +138,13 @@ func (m *MockUserRepoForTenant) CountByTenantIDs(ctx context.Context, tenantIDs
 	return args.Get(0).(map[string]int64), args.Error(1)
 }
 
-
+func (m *MockUserRepoForTenant) CountByCompanyCodes(ctx context.Context, codes []string) (map[string]int64, error) {
+	args := m.Called(ctx, codes)
+	if args.Get(0) == nil {
+		return nil, args.Error(1)
+	}
+	return args.Get(0).(map[string]int64), args.Error(1)
+}
 
 func TestTenantService_RegisterTenant_AutoVerify(t *testing.T) {
 	mockRepo := new(MockTenantRepoForSvc)
@@ -214,3 +225,18 @@ func TestTenantService_ApproveTenant_SyncAdmin(t *testing.T) {
 	mockUserRepo.AssertExpectations(t)
 	mockOutbox.AssertExpectations(t)
 }
+
+func TestTenantService_ListTenants(t *testing.T) {
+	mockRepo := new(MockTenantRepoForSvc)
+	svc := NewTenantService(mockRepo, nil, nil)
+	ctx := context.Background()
+
+	tenants := []domain.Tenant{{ID: "t1", Name: "Tenant 1"}}
+	mockRepo.On("List", ctx, 10, 0, "").Return(tenants, 1, nil)
+
+	result, total, err := svc.ListTenants(ctx, 10, 0, "")
+	assert.NoError(t, err)
+	assert.Equal(t, int64(1), total)
+	assert.Equal(t, tenants, result)
+	mockRepo.AssertExpectations(t)
+}
diff --git a/backend/internal/service/user_group_service_test.go b/backend/internal/service/user_group_service_test.go
index b740909e..e5772077 100644
--- a/backend/internal/service/user_group_service_test.go
+++ b/backend/internal/service/user_group_service_test.go
@@ -77,7 +77,7 @@ func (m *MockUserRepository) ListByTenant(ctx context.Context, tenantID string)
 	return nil, nil
 }
 
-func (m *MockUserRepository) List(ctx context.Context, offset, limit int, search string) ([]domain.User, int64, error) {
+func (m *MockUserRepository) List(ctx context.Context, offset, limit int, search string, companyCode string) ([]domain.User, int64, error) {
 	return nil, 0, nil
 }
 
@@ -94,6 +94,13 @@ func (m *MockUserRepository) CountByTenantIDs(ctx context.Context, tenantIDs []s
 	return args.Get(0).(map[string]int64), args.Error(1)
 }
 
+func (m *MockUserRepository) CountByCompanyCodes(ctx context.Context, codes []string) (map[string]int64, error) {
+	args := m.Called(ctx, codes)
+	if args.Get(0) == nil {
+		return nil, args.Error(1)
+	}
+	return args.Get(0).(map[string]int64), args.Error(1)
+}
 
 type MockTenantRepository struct {
 	mock.Mock
@@ -135,6 +142,10 @@ func (m *MockTenantRepository) AddDomain(ctx context.Context, tenantID string, d
 	return nil
 }
 
+func (m *MockTenantRepository) List(ctx context.Context, limit, offset int, parentID string) ([]domain.Tenant, int64, error) {
+	return nil, 0, nil
+}
+
 func TestUserGroupService_Create(t *testing.T) {
 	mockRepo := new(MockUserGroupRepository)
 	mockTenantRepo := new(MockTenantRepository)