diff --git a/lib/app/features/auth/views/components/identity_key_name_input/identity_key_name_input.dart b/lib/app/features/auth/views/components/identity_key_name_input/identity_key_name_input.dart
index 0162cb0fc..5e4f4a5ad 100644
--- a/lib/app/features/auth/views/components/identity_key_name_input/identity_key_name_input.dart
+++ b/lib/app/features/auth/views/components/identity_key_name_input/identity_key_name_input.dart
@@ -14,10 +14,11 @@ import 'package:ice/generated/assets.gen.dart';
 class IdentityKeyNameInput extends HookWidget {
   const IdentityKeyNameInput({
     this.textInputAction = TextInputAction.done,
-    super.key,
     this.controller,
     this.scrollPadding,
     this.notShowInfoIcon = false,
+    this.errorText,
+    super.key,
   });
 
   final TextEditingController? controller;
@@ -27,6 +28,8 @@ class IdentityKeyNameInput extends HookWidget {
   final EdgeInsets? scrollPadding;
   final bool notShowInfoIcon;
 
+  final String? errorText;
+
   @override
   Widget build(BuildContext context) {
     final hideKeyboardAndCallOnce = useHideKeyboardAndCallOnce();
@@ -67,6 +70,7 @@ class IdentityKeyNameInput extends HookWidget {
       },
       textInputAction: textInputAction,
       scrollPadding: scrollPadding ?? EdgeInsets.only(bottom: 100.0.s),
+      errorText: errorText,
     );
   }
 }
diff --git a/lib/app/features/auth/views/pages/get_started/login_form.dart b/lib/app/features/auth/views/pages/get_started/login_form.dart
index 5d82b5f80..e566d9840 100644
--- a/lib/app/features/auth/views/pages/get_started/login_form.dart
+++ b/lib/app/features/auth/views/pages/get_started/login_form.dart
@@ -29,6 +29,7 @@ class LoginForm extends HookConsumerWidget {
       child: Column(
         children: [
           IdentityKeyNameInput(
+            errorText: loginActionState.error?.toString(),
             controller: identityKeyNameController,
             scrollPadding: EdgeInsets.only(bottom: 190.0.s),
           ),
diff --git a/lib/app/features/auth/views/pages/sign_up_passkey/sign_up_passkey_form.dart b/lib/app/features/auth/views/pages/sign_up_passkey/sign_up_passkey_form.dart
index 249faa96b..10db05cfd 100644
--- a/lib/app/features/auth/views/pages/sign_up_passkey/sign_up_passkey_form.dart
+++ b/lib/app/features/auth/views/pages/sign_up_passkey/sign_up_passkey_form.dart
@@ -27,7 +27,10 @@ class SignUpPasskeyForm extends HookConsumerWidget {
       key: formKey.value,
       child: Column(
         children: [
-          IdentityKeyNameInput(controller: identityKeyNameController),
+          IdentityKeyNameInput(
+            errorText: registerActionState.error?.toString(),
+            controller: identityKeyNameController,
+          ),
           SizedBox(height: 16.0.s),
           Button(
             disabled: registerActionState.isLoading,
diff --git a/packages/ion_identity_client/lib/src/auth/data_sources/login_data_source.dart b/packages/ion_identity_client/lib/src/auth/data_sources/login_data_source.dart
index 88c93f815..9ab5ab642 100644
--- a/packages/ion_identity_client/lib/src/auth/data_sources/login_data_source.dart
+++ b/packages/ion_identity_client/lib/src/auth/data_sources/login_data_source.dart
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: ice License 1.0
 
+import 'package:dio/dio.dart';
 import 'package:ion_identity_client/src/auth/dtos/dtos.dart';
 import 'package:ion_identity_client/src/auth/result_types/login_user_result.dart';
 import 'package:ion_identity_client/src/core/network/network.dart';
@@ -28,7 +29,11 @@ class LoginDataSource {
           decoder: UserActionChallenge.fromJson,
         )
         .mapLeft(
-          (l) => const UnknownLoginUserFailure(),
+          (l) => switch (l) {
+            RequestExecutionNetworkFailure(:final error) =>
+              _handleRequestExecutionNetworkFailure(error),
+            _ => UnknownLoginUserFailure(l),
+          },
         );
   }
 
@@ -48,7 +53,24 @@ class LoginDataSource {
           decoder: Authentication.fromJson,
         )
         .mapLeft(
-          (l) => const UnknownLoginUserFailure(),
+          (l) => switch (l) {
+            RequestExecutionNetworkFailure(:final error) =>
+              _handleRequestExecutionNetworkFailure(error),
+            _ => UnknownLoginUserFailure(l),
+          },
         );
   }
+
+  LoginUserFailure _handleRequestExecutionNetworkFailure(Object error) {
+    switch (error) {
+      case DioException(:final response) when response?.statusCode == 400:
+        return const AccountDeactivatedLoginUserFailure();
+      case DioException(:final response) when response?.statusCode == 401:
+        return const NoCredentialsLoginUserFailure();
+      case DioException(:final response) when response?.statusCode == 403:
+        return const InvalidCodeLoginUserFailure();
+      default:
+        return const UnknownLoginUserFailure();
+    }
+  }
 }
diff --git a/packages/ion_identity_client/lib/src/auth/data_sources/register_data_source.dart b/packages/ion_identity_client/lib/src/auth/data_sources/register_data_source.dart
index ba3b41d9c..75a13c198 100644
--- a/packages/ion_identity_client/lib/src/auth/data_sources/register_data_source.dart
+++ b/packages/ion_identity_client/lib/src/auth/data_sources/register_data_source.dart
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: ice License 1.0
 
+import 'package:dio/dio.dart';
 import 'package:ion_identity_client/src/auth/dtos/dtos.dart';
 import 'package:ion_identity_client/src/auth/result_types/register_user_result.dart';
 import 'package:ion_identity_client/src/core/network/network.dart';
@@ -29,8 +30,9 @@ class RegisterDataSource {
         )
         .mapLeft(
           (l) => switch (l) {
-            ResponseFormatNetworkFailure() => UserAlreadyExistsRegisterUserFailure(),
-            _ => const UnknownRegisterUserFailure(),
+            RequestExecutionNetworkFailure(:final error) =>
+              _handleRequestExecutionNetworkFailure(error),
+            _ => UnknownRegisterUserFailure(l),
           },
         );
   }
@@ -39,19 +41,30 @@ class RegisterDataSource {
     required Fido2Attestation attestation,
     required String temporaryAuthenticationToken,
   }) {
-    return networkClient.post(
-      registerCompletePath,
-      data: SignedChallenge(firstFactorCredential: attestation).toJson(),
-      decoder: RegistrationCompleteResponse.fromJson,
-      headers: {
-        ...RequestHeaders.getAuthorizationHeader(token: temporaryAuthenticationToken),
-      },
-    ).mapLeft(
-      // TODO: find a complete list of user registration failures
-      (l) => switch (l) {
-        ResponseFormatNetworkFailure() => UserAlreadyExistsRegisterUserFailure(),
-        _ => const UnknownRegisterUserFailure(),
-      },
-    );
+    return networkClient
+        .post(
+          registerCompletePath,
+          data: SignedChallenge(firstFactorCredential: attestation).toJson(),
+          decoder: RegistrationCompleteResponse.fromJson,
+          headers: RequestHeaders.getAuthorizationHeader(token: temporaryAuthenticationToken),
+        )
+        .mapLeft(
+          (l) => switch (l) {
+            RequestExecutionNetworkFailure(:final error) =>
+              _handleRequestExecutionNetworkFailure(error),
+            _ => UnknownRegisterUserFailure(l),
+          },
+        );
+  }
+
+  RegisterUserFailure _handleRequestExecutionNetworkFailure(Object error) {
+    switch (error) {
+      case DioException(:final response) when response?.statusCode == 400:
+        return RegistrationCodeExpiredRegisterUserFailure();
+      case DioException(:final response) when response?.statusCode == 401:
+        return UserAlreadyExistsRegisterUserFailure();
+      default:
+        return const UnknownRegisterUserFailure();
+    }
   }
 }
diff --git a/packages/ion_identity_client/lib/src/auth/result_types/login_user_result.dart b/packages/ion_identity_client/lib/src/auth/result_types/login_user_result.dart
index a9a55cffe..2dea8aba2 100644
--- a/packages/ion_identity_client/lib/src/auth/result_types/login_user_result.dart
+++ b/packages/ion_identity_client/lib/src/auth/result_types/login_user_result.dart
@@ -12,6 +12,9 @@ sealed class LoginUserFailure extends LoginUserResult {
 
 final class PasskeyNotAvailableLoginUserFailure extends LoginUserFailure {
   const PasskeyNotAvailableLoginUserFailure();
+
+  @override
+  String toString() => 'Passkey not available';
 }
 
 final class PasskeyValidationLoginUserFailure extends LoginUserFailure {
@@ -24,7 +27,28 @@ final class PasskeyValidationLoginUserFailure extends LoginUserFailure {
   final StackTrace? stackTrace;
 
   @override
-  String toString() => 'PasskeyValidationLoginUserFailure(error: $error, stackTrace: $stackTrace)';
+  String toString() => 'Passkey validation failed: $error';
+}
+
+final class InvalidCodeLoginUserFailure extends LoginUserFailure {
+  const InvalidCodeLoginUserFailure();
+
+  @override
+  String toString() => 'Invalid code';
+}
+
+final class NoCredentialsLoginUserFailure extends LoginUserFailure {
+  const NoCredentialsLoginUserFailure();
+
+  @override
+  String toString() => 'No credentials found for this user';
+}
+
+final class AccountDeactivatedLoginUserFailure extends LoginUserFailure {
+  const AccountDeactivatedLoginUserFailure();
+
+  @override
+  String toString() => 'Account has been deactivated';
 }
 
 final class UnknownLoginUserFailure extends LoginUserFailure {
diff --git a/packages/ion_identity_client/lib/src/auth/result_types/register_user_result.dart b/packages/ion_identity_client/lib/src/auth/result_types/register_user_result.dart
index 501367423..f0a35e6f4 100644
--- a/packages/ion_identity_client/lib/src/auth/result_types/register_user_result.dart
+++ b/packages/ion_identity_client/lib/src/auth/result_types/register_user_result.dart
@@ -10,10 +10,21 @@ sealed class RegisterUserFailure extends RegisterUserResult {
   const RegisterUserFailure();
 }
 
-final class UserAlreadyExistsRegisterUserFailure extends RegisterUserFailure {}
+final class UserAlreadyExistsRegisterUserFailure extends RegisterUserFailure {
+  @override
+  String toString() => 'User already exists';
+}
+
+final class RegistrationCodeExpiredRegisterUserFailure extends RegisterUserFailure {
+  @override
+  String toString() => 'Registration code expired';
+}
 
 final class PasskeyNotAvailableRegisterUserFailure extends RegisterUserFailure {
   const PasskeyNotAvailableRegisterUserFailure();
+
+  @override
+  String toString() => 'Passkey not available';
 }
 
 final class PasskeyValidationRegisterUserFailure extends RegisterUserFailure {
@@ -26,8 +37,7 @@ final class PasskeyValidationRegisterUserFailure extends RegisterUserFailure {
   final StackTrace? stackTrace;
 
   @override
-  String toString() =>
-      'PasskeyValidationRegisterUserFailure(error: $error, stackTrace: $stackTrace)';
+  String toString() => 'Passkey validation failed: $error';
 }
 
 final class UnknownRegisterUserFailure extends RegisterUserFailure {
@@ -40,5 +50,5 @@ final class UnknownRegisterUserFailure extends RegisterUserFailure {
   final StackTrace? stackTrace;
 
   @override
-  String toString() => 'UnknownRegisterUserFailure(error: $error, stackTrace: $stackTrace)';
+  String toString() => 'Unknown error: $error';
 }