diff --git a/backend/internal/handler/auth_handler.go b/backend/internal/handler/auth_handler.go
index ec73b256..11b5ee11 100644
--- a/backend/internal/handler/auth_handler.go
+++ b/backend/internal/handler/auth_handler.go
@@ -4,6 +4,7 @@ import (
 	"baron-sso-backend/internal/domain"
 	"baron-sso-backend/internal/logger"
 	"baron-sso-backend/internal/repository"
+	"baron-sso-backend/internal/response"
 	"baron-sso-backend/internal/service"
 	"baron-sso-backend/internal/utils"
 	"bytes"
@@ -1560,7 +1561,7 @@ func (h *AuthHandler) PasswordLogin(c *fiber.Ctx) error {
 		ale.LatencyMs = time.Since(startTime)
 		ale.ProviderError = err.Error()
 		ale.Log(slog.LevelError, "Body parse error")
-		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "Invalid request body"})
+		return response.Error(c, fiber.StatusBadRequest, "bad_request", "Invalid request body")
 	}
 
 	loginID := strings.TrimSpace(req.LoginID)
@@ -1574,22 +1575,22 @@ func (h *AuthHandler) PasswordLogin(c *fiber.Ctx) error {
 		ale.LatencyMs = time.Since(startTime)
 		ale.ProviderError = "IDP Provider is nil"
 		ale.Log(slog.LevelError, "IDP Provider is nil")
-		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "Authentication service not configured"})
+		return response.Error(c, fiber.StatusInternalServerError, "service_unavailable", "Authentication service not configured")
 	}
 
 	authInfo, err := h.IdpProvider.SignIn(loginID, req.Password)
 	if err != nil {
 		if errors.Is(err, domain.ErrNotSupported) {
-			return c.Status(fiber.StatusNotImplemented).JSON(fiber.Map{"error": "Login method not supported"})
+			return response.Error(c, fiber.StatusNotImplemented, "not_supported", "Login method not supported")
 		}
 		ale.Status = fiber.StatusUnauthorized
 		ale.LatencyMs = time.Since(startTime)
 		ale.ProviderError = err.Error()
 		ale.Log(slog.LevelWarn, "IDP sign-in failed", slog.String("provider", h.IdpProvider.Name()))
 		if strings.Contains(err.Error(), "not found") || strings.Contains(err.Error(), "identity") {
-			return c.Status(fiber.StatusNotFound).JSON(fiber.Map{"error": "User not registered"})
+			return response.Error(c, fiber.StatusNotFound, "not_found", "User not registered")
 		}
-		return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "Invalid credentials"})
+		return response.Error(c, fiber.StatusUnauthorized, "password_or_email_mismatch", "Invalid credentials")
 	}
 
 	subject, resolveErr := h.resolveKratosIdentityIDFromLoginID(c.Context(), loginID)
diff --git a/backend/internal/handler/auth_handler_login_test.go b/backend/internal/handler/auth_handler_login_test.go
index 9845e738..3bb6b989 100644
--- a/backend/internal/handler/auth_handler_login_test.go
+++ b/backend/internal/handler/auth_handler_login_test.go
@@ -299,3 +299,44 @@ func TestPasswordLogin_NoOIDC_Success(t *testing.T) {
 		t.Errorf("expected no redirectTo, got %s", got["redirectTo"])
 	}
 }
+
+func TestPasswordLogin_InvalidCredentials_ReturnsCode(t *testing.T) {
+	mockIdp := new(MockIdentityProvider)
+	mockIdp.On("SignIn", "user@example.com", "wrong-password").Return(nil, errors.New("비밀번호가 일치하지 않습니다"))
+
+	h := &AuthHandler{
+		IdpProvider: mockIdp,
+		KratosAdmin: service.NewKratosAdminService(),
+		Hydra:       service.NewHydraAdminService(),
+	}
+
+	app := newAuthLoginTestApp(h)
+
+	body, _ := json.Marshal(map[string]string{
+		"loginId":  "user@example.com",
+		"password": "wrong-password",
+	})
+	req := httptest.NewRequest(http.MethodPost, "/api/v1/auth/login", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := app.Test(req)
+	if err != nil {
+		t.Fatalf("request failed: %v", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusUnauthorized {
+		t.Fatalf("expected 401, got %d", resp.StatusCode)
+	}
+
+	var got map[string]any
+	if err := json.NewDecoder(resp.Body).Decode(&got); err != nil {
+		t.Fatalf("failed to decode response: %v", err)
+	}
+	if got["code"] != "password_or_email_mismatch" {
+		t.Fatalf("expected code=password_or_email_mismatch, got=%v", got["code"])
+	}
+	if got["error"] != "Invalid credentials" {
+		t.Fatalf("expected error=Invalid credentials, got=%v", got["error"])
+	}
+}
diff --git a/locales/en.toml b/locales/en.toml
index 34f59690..6740edd9 100644
--- a/locales/en.toml
+++ b/locales/en.toml
@@ -316,6 +316,7 @@ approved_device = "Approved Device"
 approved_ip = "Approve IP: {{ip}}"
 audit_empty = "Audit Empty"
 audit_load_error = "Audit Load Error"
+render_error = "Dashboard render error: {{error}}"
 auth_method = "Auth Method"
 client_id = "Client ID: {{id}}"
 client_id_missing = "Client Id Missing"
diff --git a/locales/ko.toml b/locales/ko.toml
index a26268f5..01417815 100644
--- a/locales/ko.toml
+++ b/locales/ko.toml
@@ -316,6 +316,7 @@ approved_device = "승인 기기: {{device}}"
 approved_ip = "승인 IP: {{ip}}"
 audit_empty = "최근 접속 이력이 없습니다."
 audit_load_error = "접속이력을 불러오지 못했습니다."
+render_error = "대시보드 렌더링 오류: {{error}}"
 auth_method = "인증수단: {{method}}"
 client_id = "Client ID: {{id}}"
 client_id_missing = "Client ID 없음"
diff --git a/locales/template.toml b/locales/template.toml
index f11f6cbd..39c88db5 100644
--- a/locales/template.toml
+++ b/locales/template.toml
@@ -316,6 +316,7 @@ approved_device = ""
 approved_ip = ""
 audit_empty = ""
 audit_load_error = ""
+render_error = ""
 auth_method = ""
 client_id = ""
 client_id_missing = ""
diff --git a/userfront/assets/translations/en.toml b/userfront/assets/translations/en.toml
index e33f46ee..5cd91c17 100644
--- a/userfront/assets/translations/en.toml
+++ b/userfront/assets/translations/en.toml
@@ -38,6 +38,7 @@ approved_device = "Approved Device"
 approved_ip = "Approve IP: {ip}"
 audit_empty = "Audit Empty"
 audit_load_error = "Audit Load Error"
+render_error = "Dashboard render error: {error}"
 auth_method = "Auth Method"
 client_id = "Client ID: {id}"
 client_id_missing = "Client Id Missing"
@@ -557,4 +558,3 @@ verify = "Verify"
 
 [ui.userfront.signup.success]
 action = "Action"
-
diff --git a/userfront/assets/translations/ko.toml b/userfront/assets/translations/ko.toml
index ee1df42f..20824c45 100644
--- a/userfront/assets/translations/ko.toml
+++ b/userfront/assets/translations/ko.toml
@@ -38,6 +38,7 @@ approved_device = "승인 기기: {device}"
 approved_ip = "승인 IP: {ip}"
 audit_empty = "최근 접속 이력이 없습니다."
 audit_load_error = "접속이력을 불러오지 못했습니다."
+render_error = "대시보드 렌더링 오류: {error}"
 auth_method = "인증수단: {method}"
 client_id = "Client ID: {id}"
 client_id_missing = "Client ID 없음"
@@ -557,4 +558,3 @@ verify = "본인인증"
 
 [ui.userfront.signup.success]
 action = "로그인하기"
-
diff --git a/userfront/assets/translations/template.toml b/userfront/assets/translations/template.toml
index 9ee024cb..cb29cf60 100644
--- a/userfront/assets/translations/template.toml
+++ b/userfront/assets/translations/template.toml
@@ -38,6 +38,7 @@ approved_device = ""
 approved_ip = ""
 audit_empty = ""
 audit_load_error = ""
+render_error = ""
 auth_method = ""
 client_id = ""
 client_id_missing = ""