diff --git a/src/woocommerce-gateway-ratenkaufbyeasycredit/includes/class-wc-gateway-ratenkaufbyeasycredit.php b/src/woocommerce-gateway-ratenkaufbyeasycredit/includes/class-wc-gateway-ratenkaufbyeasycredit.php
index 1b4ca87..f971e82 100644
--- a/src/woocommerce-gateway-ratenkaufbyeasycredit/includes/class-wc-gateway-ratenkaufbyeasycredit.php
+++ b/src/woocommerce-gateway-ratenkaufbyeasycredit/includes/class-wc-gateway-ratenkaufbyeasycredit.php
@@ -204,7 +204,7 @@ protected function create_express_checkout_order($transaction) {
         $updateAddress($transaction->getTransaction()->getOrderDetails()->getShippingAddress(), 'shipping');
 
         $contact = $transaction->getTransaction()->getCustomer()->getContact();
-        WC()->customer->set_billing_phone($contact->getPhoneNumber());
+        WC()->customer->set_billing_phone($contact->getMobilePhoneNumber());
         WC()->customer->set_billing_email($contact->getEmail());
         WC()->customer->save();