diff --git a/src/DTO/MFilesError.php b/src/DTO/MFilesError.php
new file mode 100644
index 0000000..c5205b4
--- /dev/null
+++ b/src/DTO/MFilesError.php
@@ -0,0 +1,48 @@
+<?php
+
+declare(strict_types=1);
+
+namespace CodebarAg\MFiles\DTO;
+
+use Illuminate\Support\Arr;
+
+final class MFilesError
+{
+    public function __construct(
+        public readonly string $errorCode,
+        public readonly int $status,
+        public readonly string $url,
+        public readonly string $method,
+        public readonly string $exceptionName,
+        public readonly string $exceptionMessage,
+        public readonly ?string $stack,
+    ) {}
+
+    public static function fromArray(array $data): self
+    {
+        $exceptionData = Arr::get($data, 'Exception', []);
+
+        return new self(
+            errorCode: Arr::get($data, 'ErrorCode', ''),
+            status: Arr::get($data, 'Status', 0),
+            url: Arr::get($data, 'URL', ''),
+            method: Arr::get($data, 'Method', ''),
+            exceptionName: Arr::get($exceptionData, 'Name', ''),
+            exceptionMessage: Arr::get($exceptionData, 'Message', ''),
+            stack: Arr::get($data, 'Stack'),
+        );
+    }
+
+    public function toArray(): array
+    {
+        return [
+            'errorCode' => $this->errorCode,
+            'status' => $this->status,
+            'url' => $this->url,
+            'method' => $this->method,
+            'exceptionName' => $this->exceptionName,
+            'exceptionMessage' => $this->exceptionMessage,
+            'stack' => $this->stack,
+        ];
+    }
+}
diff --git a/src/Exceptions/MFilesErrorException.php b/src/Exceptions/MFilesErrorException.php
new file mode 100644
index 0000000..a6d313e
--- /dev/null
+++ b/src/Exceptions/MFilesErrorException.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace CodebarAg\MFiles\Exceptions;
+
+use CodebarAg\MFiles\DTO\MFilesError;
+use Exception as BaseException;
+
+final class MFilesErrorException extends BaseException
+{
+    public function __construct(
+        public readonly MFilesError $error
+    ) {
+        parent::__construct($error->exceptionMessage, $error->status);
+    }
+}
diff --git a/src/Responses/DownloadFileResponse.php b/src/Responses/DownloadFileResponse.php
index 006ce2e..4126400 100644
--- a/src/Responses/DownloadFileResponse.php
+++ b/src/Responses/DownloadFileResponse.php
@@ -5,12 +5,16 @@
 namespace CodebarAg\MFiles\Responses;
 
 use CodebarAg\MFiles\DTO\DownloadedFile;
+use CodebarAg\MFiles\Exceptions\MFilesErrorException;
 use Saloon\Http\Response;
 
 final class DownloadFileResponse
 {
     public static function createDtoFromResponse(Response $response): DownloadedFile
     {
+        if (! $response->successful()) {
+            throw new MFilesErrorException(ErrorResponse::createDtoFromResponse($response));
+        }
         $headers = $response->headers();
         $fileContentType = $headers->get('Content-Type');
         $fileSize = (int) $headers->get('Content-Length', 0);
diff --git a/src/Responses/ErrorResponse.php b/src/Responses/ErrorResponse.php
new file mode 100644
index 0000000..e24c45a
--- /dev/null
+++ b/src/Responses/ErrorResponse.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace CodebarAg\MFiles\Responses;
+
+use CodebarAg\MFiles\DTO\MFilesError;
+use Saloon\Http\Response;
+
+final class ErrorResponse
+{
+    public static function createDtoFromResponse(Response $response): MFilesError
+    {
+        return MFilesError::fromArray($response->json());
+    }
+}
diff --git a/src/Responses/LogInToVaultResponse.php b/src/Responses/LogInToVaultResponse.php
index 7312a4e..6d6fba4 100644
--- a/src/Responses/LogInToVaultResponse.php
+++ b/src/Responses/LogInToVaultResponse.php
@@ -4,6 +4,7 @@
 
 namespace CodebarAg\MFiles\Responses;
 
+use CodebarAg\MFiles\Exceptions\MFilesErrorException;
 use Illuminate\Support\Arr;
 use Saloon\Http\Response;
 
@@ -11,6 +12,10 @@ final class LogInToVaultResponse
 {
     public static function createDtoFromResponse(Response $response): ?string
     {
+        if (! $response->successful()) {
+            throw new MFilesErrorException(ErrorResponse::createDtoFromResponse($response));
+        }
+
         return Arr::get($response->json(), 'Value');
     }
 }
diff --git a/src/Responses/ObjectPropertiesResponse.php b/src/Responses/ObjectPropertiesResponse.php
index bc4ef0c..6b68dc9 100644
--- a/src/Responses/ObjectPropertiesResponse.php
+++ b/src/Responses/ObjectPropertiesResponse.php
@@ -5,12 +5,17 @@
 namespace CodebarAg\MFiles\Responses;
 
 use CodebarAg\MFiles\DTO\ObjectProperties;
+use CodebarAg\MFiles\Exceptions\MFilesErrorException;
 use Saloon\Http\Response;
 
 final class ObjectPropertiesResponse
 {
     public static function createDtoFromResponse(Response $response): ObjectProperties
     {
+        if (! $response->successful()) {
+            throw new MFilesErrorException(ErrorResponse::createDtoFromResponse($response));
+        }
+
         return ObjectProperties::fromArray($response->json());
     }
 }
diff --git a/src/Responses/UploadFileResponse.php b/src/Responses/UploadFileResponse.php
index 8b799a5..1dd6787 100644
--- a/src/Responses/UploadFileResponse.php
+++ b/src/Responses/UploadFileResponse.php
@@ -4,6 +4,7 @@
 
 namespace CodebarAg\MFiles\Responses;
 
+use CodebarAg\MFiles\Exceptions\MFilesErrorException;
 use Illuminate\Support\Arr;
 use Illuminate\Support\Str;
 use Saloon\Http\Response;
@@ -12,6 +13,10 @@ final class UploadFileResponse
 {
     public static function createDtoFromResponse(Response $response, string $fileName): array
     {
+        if (! $response->successful()) {
+            throw new MFilesErrorException(ErrorResponse::createDtoFromResponse($response));
+        }
+
         $data = $response->json();
         $data = Arr::add($data, 'Title', Str::beforeLast($fileName, '.'));
         $data = Arr::add($data, 'Extension', Str::afterLast($fileName, '.'));
diff --git a/tests/Unit/DTO/MFilesErrorTest.php b/tests/Unit/DTO/MFilesErrorTest.php
new file mode 100644
index 0000000..ca551cc
--- /dev/null
+++ b/tests/Unit/DTO/MFilesErrorTest.php
@@ -0,0 +1,141 @@
+<?php
+
+declare(strict_types=1);
+
+use CodebarAg\MFiles\DTO\MFilesError;
+
+it('creates instance with all properties', function () {
+    $error = new MFilesError(
+        errorCode: 'ERROR_001',
+        status: 403,
+        url: '/session/vaults',
+        method: 'GET',
+        exceptionName: 'UnauthorizedAccessException',
+        exceptionMessage: 'Login to application failed',
+        stack: 'Stack trace here'
+    );
+
+    expect($error->errorCode)->toBe('ERROR_001');
+    expect($error->status)->toBe(403);
+    expect($error->url)->toBe('/session/vaults');
+    expect($error->method)->toBe('GET');
+    expect($error->exceptionName)->toBe('UnauthorizedAccessException');
+    expect($error->exceptionMessage)->toBe('Login to application failed');
+    expect($error->stack)->toBe('Stack trace here');
+});
+
+it('creates instance with null stack', function () {
+    $error = new MFilesError(
+        errorCode: 'ERROR_002',
+        status: 404,
+        url: '/objects/123',
+        method: 'GET',
+        exceptionName: 'NotFoundException',
+        exceptionMessage: 'Object not found',
+        stack: null
+    );
+
+    expect($error->stack)->toBeNull();
+});
+
+it('creates instance from array with all properties', function () {
+    $data = [
+        'ErrorCode' => 'ERROR_003',
+        'Status' => 500,
+        'URL' => '/api/endpoint',
+        'Method' => 'POST',
+        'Exception' => [
+            'Name' => 'InternalServerError',
+            'Message' => 'Internal server error occurred',
+        ],
+        'Stack' => 'Detailed stack trace',
+    ];
+
+    $error = MFilesError::fromArray($data);
+
+    expect($error->errorCode)->toBe('ERROR_003');
+    expect($error->status)->toBe(500);
+    expect($error->url)->toBe('/api/endpoint');
+    expect($error->method)->toBe('POST');
+    expect($error->exceptionName)->toBe('InternalServerError');
+    expect($error->exceptionMessage)->toBe('Internal server error occurred');
+    expect($error->stack)->toBe('Detailed stack trace');
+});
+
+it('creates instance from array with missing optional fields', function () {
+    $data = [
+        'Status' => 400,
+        'URL' => '/test',
+        'Method' => 'GET',
+        'Exception' => [
+            'Name' => 'BadRequest',
+            'Message' => 'Bad request',
+        ],
+    ];
+
+    $error = MFilesError::fromArray($data);
+
+    expect($error->errorCode)->toBe('');
+    expect($error->status)->toBe(400);
+    expect($error->url)->toBe('/test');
+    expect($error->method)->toBe('GET');
+    expect($error->exceptionName)->toBe('BadRequest');
+    expect($error->exceptionMessage)->toBe('Bad request');
+    expect($error->stack)->toBeNull();
+});
+
+it('creates instance from array with empty exception object', function () {
+    $data = [
+        'ErrorCode' => 'ERROR_004',
+        'Status' => 401,
+        'URL' => '/auth',
+        'Method' => 'POST',
+        'Exception' => [],
+        'Stack' => null,
+    ];
+
+    $error = MFilesError::fromArray($data);
+
+    expect($error->exceptionName)->toBe('');
+    expect($error->exceptionMessage)->toBe('');
+});
+
+it('converts instance to array correctly', function () {
+    $error = new MFilesError(
+        errorCode: 'ERROR_005',
+        status: 422,
+        url: '/validate',
+        method: 'PUT',
+        exceptionName: 'ValidationError',
+        exceptionMessage: 'Validation failed',
+        stack: 'Error stack'
+    );
+
+    $array = $error->toArray();
+
+    expect($array)->toBe([
+        'errorCode' => 'ERROR_005',
+        'status' => 422,
+        'url' => '/validate',
+        'method' => 'PUT',
+        'exceptionName' => 'ValidationError',
+        'exceptionMessage' => 'Validation failed',
+        'stack' => 'Error stack',
+    ]);
+});
+
+it('converts instance to array with null stack', function () {
+    $error = new MFilesError(
+        errorCode: 'ERROR_006',
+        status: 500,
+        url: '/test',
+        method: 'DELETE',
+        exceptionName: 'ServerError',
+        exceptionMessage: 'Server error',
+        stack: null
+    );
+
+    $array = $error->toArray();
+
+    expect($array['stack'])->toBeNull();
+});
diff --git a/tests/Unit/Exceptions/MFilesErrorExceptionTest.php b/tests/Unit/Exceptions/MFilesErrorExceptionTest.php
new file mode 100644
index 0000000..b4cf2f2
--- /dev/null
+++ b/tests/Unit/Exceptions/MFilesErrorExceptionTest.php
@@ -0,0 +1,62 @@
+<?php
+
+declare(strict_types=1);
+
+use CodebarAg\MFiles\DTO\MFilesError;
+use CodebarAg\MFiles\Exceptions\MFilesErrorException;
+
+it('creates exception with MFilesError', function () {
+    $error = new MFilesError(
+        errorCode: 'ERROR_001',
+        status: 403,
+        url: '/session/vaults',
+        method: 'GET',
+        exceptionName: 'UnauthorizedAccessException',
+        exceptionMessage: 'Login to application failed',
+        stack: 'Stack trace here'
+    );
+
+    $exception = new MFilesErrorException($error);
+
+    expect($exception->error)->toBe($error);
+    expect($exception->getMessage())->toBe('Login to application failed');
+    expect($exception->getCode())->toBe(403);
+});
+
+it('extends base Exception class', function () {
+    $error = new MFilesError(
+        errorCode: 'ERROR_002',
+        status: 404,
+        url: '/objects/123',
+        method: 'GET',
+        exceptionName: 'NotFoundException',
+        exceptionMessage: 'Object not found',
+        stack: null
+    );
+
+    $exception = new MFilesErrorException($error);
+
+    expect($exception)->toBeInstanceOf(Exception::class);
+});
+
+it('can access error properties through exception', function () {
+    $error = new MFilesError(
+        errorCode: 'ERROR_003',
+        status: 500,
+        url: '/api/endpoint',
+        method: 'POST',
+        exceptionName: 'InternalServerError',
+        exceptionMessage: 'Internal server error occurred',
+        stack: 'Detailed stack trace'
+    );
+
+    $exception = new MFilesErrorException($error);
+
+    expect($exception->error->errorCode)->toBe('ERROR_003');
+    expect($exception->error->status)->toBe(500);
+    expect($exception->error->url)->toBe('/api/endpoint');
+    expect($exception->error->method)->toBe('POST');
+    expect($exception->error->exceptionName)->toBe('InternalServerError');
+    expect($exception->error->exceptionMessage)->toBe('Internal server error occurred');
+    expect($exception->error->stack)->toBe('Detailed stack trace');
+});
diff --git a/tests/Unit/Responses/ErrorResponseTest.php b/tests/Unit/Responses/ErrorResponseTest.php
new file mode 100644
index 0000000..435e55a
--- /dev/null
+++ b/tests/Unit/Responses/ErrorResponseTest.php
@@ -0,0 +1,139 @@
+<?php
+
+declare(strict_types=1);
+
+use CodebarAg\MFiles\DTO\MFilesError;
+use CodebarAg\MFiles\Responses\ErrorResponse;
+use Saloon\Enums\Method;
+use Saloon\Http\Connector;
+use Saloon\Http\Faking\MockResponse;
+use Saloon\Http\Request;
+use Saloon\Laravel\Facades\Saloon;
+
+it('creates MFilesError from response json', function () {
+    $json = [
+        'ErrorCode' => 'ERROR_001',
+        'Status' => 403,
+        'URL' => '/session/vaults',
+        'Method' => 'GET',
+        'Exception' => [
+            'Name' => 'UnauthorizedAccessException',
+            'Message' => 'Login to application failed',
+        ],
+        'Stack' => 'Stack trace here',
+    ];
+
+    $request = new class extends Request
+    {
+        protected Method $method = Method::GET;
+
+        public function resolveEndpoint(): string
+        {
+            return '/test';
+        }
+    };
+
+    Saloon::fake([
+        get_class($request) => MockResponse::make(status: 403, body: json_encode($json)),
+    ]);
+
+    $connector = new class extends Connector
+    {
+        public function resolveBaseUrl(): string
+        {
+            return 'https://test.example.com';
+        }
+    };
+
+    $response = $connector->send($request);
+
+    $error = ErrorResponse::createDtoFromResponse($response);
+
+    expect($error)->toBeInstanceOf(MFilesError::class);
+    expect($error->errorCode)->toBe('ERROR_001');
+    expect($error->status)->toBe(403);
+    expect($error->url)->toBe('/session/vaults');
+    expect($error->method)->toBe('GET');
+    expect($error->exceptionName)->toBe('UnauthorizedAccessException');
+    expect($error->exceptionMessage)->toBe('Login to application failed');
+    expect($error->stack)->toBe('Stack trace here');
+});
+
+it('handles response with missing optional fields', function () {
+    $json = [
+        'Status' => 400,
+        'URL' => '/test',
+        'Method' => 'POST',
+        'Exception' => [
+            'Name' => 'BadRequest',
+            'Message' => 'Bad request',
+        ],
+    ];
+
+    $request = new class extends Request
+    {
+        protected Method $method = Method::GET;
+
+        public function resolveEndpoint(): string
+        {
+            return '/test';
+        }
+    };
+
+    Saloon::fake([
+        get_class($request) => MockResponse::make(status: 400, body: json_encode($json)),
+    ]);
+
+    $connector = new class extends Connector
+    {
+        public function resolveBaseUrl(): string
+        {
+            return 'https://test.example.com';
+        }
+    };
+
+    $response = $connector->send($request);
+
+    $error = ErrorResponse::createDtoFromResponse($response);
+
+    expect($error->errorCode)->toBe('');
+    expect($error->stack)->toBeNull();
+});
+
+it('handles empty exception object', function () {
+    $json = [
+        'Status' => 500,
+        'URL' => '/api',
+        'Method' => 'GET',
+        'Exception' => [],
+    ];
+
+    $request = new class extends Request
+    {
+        protected Method $method = Method::GET;
+
+        public function resolveEndpoint(): string
+        {
+            return '/test';
+        }
+    };
+
+    Saloon::fake([
+        get_class($request) => MockResponse::make(status: 500, body: json_encode($json)),
+    ]);
+
+    $connector = new class extends Connector
+    {
+        public function resolveBaseUrl(): string
+        {
+            return 'https://test.example.com';
+        }
+    };
+
+    $response = $connector->send($request);
+
+    $error = ErrorResponse::createDtoFromResponse($response);
+
+    expect($error->exceptionName)->toBe('');
+    expect($error->exceptionMessage)->toBe('');
+});