diff --git a/composer.json b/composer.json
index ab767ec..d7855c6 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,8 @@
     "composer/composer": "^2.7.1",
     "doctrine/collections": "^1.8.0",
     "guzzlehttp/guzzle": "~7.0",
-    "ext-json": "*"
+    "ext-json": "*",
+    "beberlei/assert": "^3.3"
   },
   "require-dev": {
     "phpunit/phpunit": "^9.3",
diff --git a/src/Exceptions/BaseException.php b/src/Exceptions/BaseException.php
index 5af096d..908200d 100644
--- a/src/Exceptions/BaseException.php
+++ b/src/Exceptions/BaseException.php
@@ -19,7 +19,7 @@ namespace D3\KlicktippPhpClient\Exceptions;
 
 use Exception;
 
-class BaseException extends Exception
+class BaseException extends Exception implements KlicktippExceptionInterface
 {
     public function __construct($message = "", $code = 0, Exception $previous = null)
     {
diff --git a/src/Exceptions/InvalidCredentialTypeException.php b/src/Exceptions/InvalidCredentialTypeException.php
new file mode 100644
index 0000000..ba602f2
--- /dev/null
+++ b/src/Exceptions/InvalidCredentialTypeException.php
@@ -0,0 +1,24 @@
+<?php
+
+/**
+ * Copyright (c) D3 Data Development (Inh. Thomas Dartsch)
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * https://www.d3data.de
+ *
+ * @copyright (C) D3 Data Development (Inh. Thomas Dartsch)
+ * @author    D3 Data Development - Daniel Seifert <info@shopmodule.com>
+ * @link      https://www.oxidmodule.com
+ */
+
+declare(strict_types=1);
+
+namespace D3\KlicktippPhpClient\Exceptions;
+
+use Assert\LazyAssertionException;
+
+class InvalidCredentialTypeException extends LazyAssertionException implements KlicktippExceptionInterface
+{
+}
diff --git a/src/Exceptions/KlicktippExceptionInterface.php b/src/Exceptions/KlicktippExceptionInterface.php
new file mode 100644
index 0000000..fdec70b
--- /dev/null
+++ b/src/Exceptions/KlicktippExceptionInterface.php
@@ -0,0 +1,20 @@
+<?php
+
+/**
+ * Copyright (c) D3 Data Development (Inh. Thomas Dartsch)
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * https://www.d3data.de
+ *
+ * @copyright (C) D3 Data Development (Inh. Thomas Dartsch)
+ * @author    D3 Data Development - Daniel Seifert <info@shopmodule.com>
+ * @link      https://www.oxidmodule.com
+ */
+
+declare(strict_types=1);
+
+namespace D3\KlicktippPhpClient\Exceptions;
+
+interface KlicktippExceptionInterface {}
\ No newline at end of file
diff --git a/src/Exceptions/NoCredentialsException.php b/src/Exceptions/NoCredentialsException.php
index 59c5a09..cfb5125 100644
--- a/src/Exceptions/NoCredentialsException.php
+++ b/src/Exceptions/NoCredentialsException.php
@@ -17,6 +17,8 @@ declare(strict_types=1);
 
 namespace D3\KlicktippPhpClient\Exceptions;
 
-class NoCredentialsException extends BaseException
+use Assert\LazyAssertionException;
+
+class NoCredentialsException extends LazyAssertionException implements KlicktippExceptionInterface
 {
 }