diff --git a/userfront/lib/core/services/auth_proxy_service.dart b/userfront/lib/core/services/auth_proxy_service.dart
index cebe659e..fa0bdef0 100644
--- a/userfront/lib/core/services/auth_proxy_service.dart
+++ b/userfront/lib/core/services/auth_proxy_service.dart
@@ -516,8 +516,13 @@ class AuthProxyService {
       return jsonDecode(response.body);
     } else {
       final errorBody = jsonDecode(response.body);
-      throw Exception(
-        errorBody['error'] ?? tr('err.userfront.auth_proxy.oidc_accept'),
+      final rawDetails = errorBody['details'];
+      throw AuthProxyException(
+        errorCode: (errorBody['code'] ?? '').toString(),
+        message:
+            (errorBody['error'] ?? tr('err.userfront.auth_proxy.oidc_accept'))
+                .toString(),
+        details: rawDetails is Map<String, dynamic> ? rawDetails : null,
       );
     }
   }
diff --git a/userfront/lib/features/auth/domain/consent_error_routing.dart b/userfront/lib/features/auth/domain/consent_error_routing.dart
index 3526352b..93c97503 100644
--- a/userfront/lib/features/auth/domain/consent_error_routing.dart
+++ b/userfront/lib/features/auth/domain/consent_error_routing.dart
@@ -1,5 +1,29 @@
+import 'dart:convert';
+
+import 'package:userfront/core/i18n/locale_utils.dart';
 import 'package:userfront/core/services/auth_proxy_service.dart';
 
-bool shouldRouteConsentErrorToErrorScreen(Object error) {
+bool shouldRouteTenantAccessErrorToErrorScreen(Object error) {
   return error is AuthProxyException && error.errorCode == 'tenant_not_allowed';
 }
+
+bool shouldRouteConsentErrorToErrorScreen(Object error) {
+  return shouldRouteTenantAccessErrorToErrorScreen(error);
+}
+
+String buildTenantAccessErrorPath(Object error, Uri baseUri) {
+  final authError = error as AuthProxyException;
+  final localeCode =
+      extractLocaleFromPath(baseUri) ?? resolvePreferredLocaleCode();
+  return buildLocalizedPath(
+    localeCode,
+    Uri(
+      path: '/error',
+      queryParameters: {
+        'error': authError.errorCode,
+        'error_description': authError.message,
+        if (authError.details != null) 'details': jsonEncode(authError.details),
+      },
+    ),
+  );
+}
diff --git a/userfront/lib/features/auth/presentation/consent_screen.dart b/userfront/lib/features/auth/presentation/consent_screen.dart
index cddf6c5a..7e7d44cd 100644
--- a/userfront/lib/features/auth/presentation/consent_screen.dart
+++ b/userfront/lib/features/auth/presentation/consent_screen.dart
@@ -1,5 +1,3 @@
-import 'dart:convert';
-
 import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import 'package:userfront/i18n.dart';
@@ -153,19 +151,7 @@ class _ConsentScreenState extends State<ConsentScreen> {
         if (!mounted) {
           return;
         }
-        final localeCode =
-            extractLocaleFromPath(Uri.base) ?? resolvePreferredLocaleCode();
-        final target = buildLocalizedPath(
-          localeCode,
-          Uri(
-            path: '/error',
-            queryParameters: {
-              'error': e.errorCode,
-              'error_description': e.message,
-              if (e.details != null) 'details': jsonEncode(e.details),
-            },
-          ),
-        );
+        final target = buildTenantAccessErrorPath(e, Uri.base);
         context.go(target);
         return;
       }
diff --git a/userfront/lib/features/auth/presentation/login_screen.dart b/userfront/lib/features/auth/presentation/login_screen.dart
index f8809bfb..83931cef 100644
--- a/userfront/lib/features/auth/presentation/login_screen.dart
+++ b/userfront/lib/features/auth/presentation/login_screen.dart
@@ -17,6 +17,7 @@ import '../../../core/services/oidc_redirect_guard.dart';
 import '../../../core/notifiers/auth_notifier.dart';
 import '../domain/login_challenge_resolver.dart';
 import '../domain/cookie_session_policy.dart';
+import '../domain/consent_error_routing.dart';
 import '../domain/login_link_route_policy.dart';
 import '../domain/verification_completion_route.dart';
 import '../../profile/domain/notifiers/profile_notifier.dart';
@@ -1666,6 +1667,16 @@ class _LoginScreenState extends ConsumerState<LoginScreen>
             return;
           } else {}
         } catch (e) {
+          if (e is AuthProxyException &&
+              shouldRouteTenantAccessErrorToErrorScreen(e)) {
+            final target = buildTenantAccessErrorPath(e, Uri.base);
+            if (mounted) {
+              context.go(target);
+            } else {
+              webWindow.redirectTo(target);
+            }
+            return;
+          }
           _showError(tr('msg.userfront.login.oidc_failed'));
           return;
         }
diff --git a/userfront/test/auth_proxy_service_test.dart b/userfront/test/auth_proxy_service_test.dart
index 2bb32714..9d46dba0 100644
--- a/userfront/test/auth_proxy_service_test.dart
+++ b/userfront/test/auth_proxy_service_test.dart
@@ -153,6 +153,37 @@ void main() {
       },
     );
 
+    test(
+      'acceptOidcLogin error는 code/message/details를 AuthProxyException으로 보존한다',
+      () async {
+        client.enqueueJson({
+          'code': 'tenant_not_allowed',
+          'error': 'tenant blocked',
+          'details': {
+            'allowed_tenants': ['gp'],
+          },
+        }, statusCode: 403);
+
+        await expectLater(
+          AuthProxyService.acceptOidcLogin('login-challenge', token: 'jwt'),
+          throwsA(
+            isA<AuthProxyException>()
+                .having(
+                  (error) => error.errorCode,
+                  'code',
+                  'tenant_not_allowed',
+                )
+                .having((error) => error.message, 'message', 'tenant blocked')
+                .having(
+                  (error) => error.details?['allowed_tenants'],
+                  'details',
+                  ['gp'],
+                ),
+          ),
+        );
+      },
+    );
+
     test(
       'approveQrLogin은 credential mode와 bearer token payload를 지원한다',
       () async {
diff --git a/userfront/test/consent_error_routing_test.dart b/userfront/test/consent_error_routing_test.dart
index 4373e3d1..9894ee45 100644
--- a/userfront/test/consent_error_routing_test.dart
+++ b/userfront/test/consent_error_routing_test.dart
@@ -20,4 +20,33 @@ void main() {
 
     expect(shouldRouteConsentErrorToErrorScreen(error), isFalse);
   });
+
+  test('tenant_not_allowed auth error also routes to error screen', () {
+    const error = AuthProxyException(
+      errorCode: 'tenant_not_allowed',
+      message: '허용되지 않은 테넌트입니다.',
+    );
+
+    expect(shouldRouteTenantAccessErrorToErrorScreen(error), isTrue);
+  });
+
+  test('buildTenantAccessErrorPath builds userfront error route', () {
+    const error = AuthProxyException(
+      errorCode: 'tenant_not_allowed',
+      message: '허용되지 않은 테넌트입니다.',
+      details: {
+        'allowed_tenants': ['tenant-a'],
+      },
+    );
+
+    final target = buildTenantAccessErrorPath(
+      error,
+      Uri.parse('https://sso-test.hmac.kr/ko?login_challenge=abc'),
+    );
+
+    expect(target, contains('/error?'));
+    expect(target, contains('error=tenant_not_allowed'));
+    expect(target, contains('error_description='));
+    expect(target, contains('details='));
+  });
 }