diff --git a/Tests/Request/AbstractRequest.php b/Tests/Request/AbstractRequest.php
index 494c550..2e79b64 100644
--- a/Tests/Request/AbstractRequest.php
+++ b/Tests/Request/AbstractRequest.php
@@ -465,10 +465,55 @@ abstract class AbstractRequest extends ApiTestCase
     /**
      * @test
      * @throws ReflectionException
+     * @dataProvider setGetSenderAddressTypeDataProvider
      */
-    public function setGetSenderAddressTypeTest()
+    public function testSetGetSenderAddressType($hasSender, $addressType, $expected)
     {
-        $this->checkGetterSetter('fixture', 'setSenderAddressType', 'getSenderAddressType');
+        /** @var Request|MockObject $request */
+        $request = $this->getMockBuilder($this->testClassName)
+            ->setConstructorArgs([$this->request->getMessage(), $this->request->getClient()])
+            ->onlyMethods(['getSenderAddress'])
+            ->getMock();
+
+        if ($hasSender) {
+            /** @var Sender|MockObject $senderMock */
+            $senderMock = $this->getMockBuilder( Sender::class )
+                ->disableOriginalConstructor()
+                ->onlyMethods(['get'])
+                ->getMock();
+            $senderMock->method('get')->willReturn('fixture');
+            $request->method('getSenderAddress')->willReturn($senderMock);
+        } else {
+            $request->method('getSenderAddress')->willReturn(null);
+        }
+
+        $this->assertInstanceOf(
+            Request::class,
+            $this->callMethod(
+                $request,
+                'setSenderAddressType',
+                [$addressType]
+            )
+        );
+
+        $this->assertSame(
+            $expected,
+            $this->callMethod(
+                $request,
+                'getSenderAddressType'
+            )
+        );
+    }
+
+    /**
+     * @return array[]
+     */
+    public function setGetSenderAddressTypeDataProvider(): array
+    {
+        return [
+            'has no sender'                 => [false, 'fixture', null],
+            'has sender and address type'   => [true, 'fixture', 'fixture'],
+        ];
     }
 
     /**
diff --git a/src/Exceptions/ExceptionMessages.php b/src/Exceptions/ExceptionMessages.php
index d2ec7e1..99ae8f9 100644
--- a/src/Exceptions/ExceptionMessages.php
+++ b/src/Exceptions/ExceptionMessages.php
@@ -17,11 +17,13 @@ namespace D3\LinkmobilityClient\Exceptions;
 
 class ExceptionMessages
 {
-    public const INVALID_SENDER            = 'invalid sender phone number';
+    public const INVALID_SENDER             = 'invalid sender phone number';
 
-    public const NOK_REQUEST_RETURN        = 'request %1$s returns status code %2$s';
+    public const NOK_REQUEST_RETURN         = 'request %1$s returns status code %2$s';
 
-    public const INVALID_RECIPIENT_PHONE   = 'invalid recipient phone number';
+    public const INVALID_RECIPIENT_PHONE    = 'invalid recipient phone number';
 
-    public const NOT_A_MOBILE_NUMBER       = 'not a mobile number';
+    public const NOT_A_MOBILE_NUMBER        = 'not a mobile number';
+
+    public const DEBUG_NOSENDERORCOUNTRYCODE= 'no sender number or sender country code defined, use fallback to account default';
 }
diff --git a/src/Exceptions/NoSenderDefinedException.php b/src/Exceptions/NoSenderDefinedException.php
new file mode 100644
index 0000000..e79d27c
--- /dev/null
+++ b/src/Exceptions/NoSenderDefinedException.php
@@ -0,0 +1,21 @@
+<?php
+
+/**
+ * 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 <support@shopmodule.com>
+ * @link      https://www.oxidmodule.com
+ */
+
+declare(strict_types=1);
+
+namespace D3\LinkmobilityClient\Exceptions;
+
+class NoSenderDefinedException extends LinkmobilityException
+{
+
+}
\ No newline at end of file
diff --git a/src/Request/Request.php b/src/Request/Request.php
index c7091b0..3483bfe 100644
--- a/src/Request/Request.php
+++ b/src/Request/Request.php
@@ -465,7 +465,7 @@ abstract class Request implements RequestInterface
      */
     public function getSenderAddressType()
     {
-        return $this->senderAddressType;
+        return $this->getSenderAddress() && $this->getSenderAddress()->get() ? $this->senderAddressType : null;
     }
 
     /**
diff --git a/src/ValueObject/Sender.php b/src/ValueObject/Sender.php
index 40fc074..72b06f9 100644
--- a/src/ValueObject/Sender.php
+++ b/src/ValueObject/Sender.php
@@ -17,7 +17,9 @@ namespace D3\LinkmobilityClient\ValueObject;
 
 use Assert\Assert;
 use D3\LinkmobilityClient\Exceptions\ExceptionMessages;
+use D3\LinkmobilityClient\Exceptions\NoSenderDefinedException;
 use D3\LinkmobilityClient\Exceptions\RecipientException;
+use D3\LinkmobilityClient\LoggerHandler;
 use libphonenumber\NumberParseException;
 use libphonenumber\PhoneNumberFormat;
 use libphonenumber\PhoneNumberUtil;
@@ -31,20 +33,30 @@ class Sender extends StringValueObject
      * @throws RecipientException
      * @throws NumberParseException
      */
-    public function __construct(string $number, string $iso2CountryCode)
+    public function __construct(string $number = null, string $iso2CountryCode = null)
     {
-        Assert::that($iso2CountryCode)->string()->length(2);
+        try {
+            if ( is_null( $number ) || is_null( $iso2CountryCode ) ) {
+                throw new NoSenderDefinedException();
+            }
 
-        $phoneUtil = $this->getPhoneNumberUtil();
+            Assert::that( $iso2CountryCode )->string()->length( 2 );
 
-        $phoneNumber = $phoneUtil->parse($number, strtoupper($iso2CountryCode));
-        $number = ltrim($phoneUtil->format($phoneNumber, PhoneNumberFormat::E164), '+');
+            $phoneUtil = $this->getPhoneNumberUtil();
 
-        if (false === $phoneUtil->isValidNumber($phoneNumber)) {
-            throw new RecipientException(ExceptionMessages::INVALID_SENDER);
+            $phoneNumber = $phoneUtil->parse( $number, strtoupper( $iso2CountryCode ) );
+            $number      = ltrim( $phoneUtil->format( $phoneNumber, PhoneNumberFormat::E164 ), '+' );
+
+            if ( false === $phoneUtil->isValidNumber( $phoneNumber ) ) {
+                throw new RecipientException( ExceptionMessages::INVALID_SENDER );
+            }
+
+            parent::__construct( $number );
+        } catch (NoSenderDefinedException $e) {
+            LoggerHandler::getInstance()->getLogger()->debug(
+                ExceptionMessages::DEBUG_NOSENDERORCOUNTRYCODE
+            );
         }
-
-        parent::__construct($number);
     }
 
     /**
@@ -54,12 +66,4 @@ class Sender extends StringValueObject
     {
         return PhoneNumberUtil::getInstance();
     }
-
-    /**
-     * @return int
-     */
-    public function getFormatted()
-    {
-        return parent::getFormatted();
-    }
 }