ENGCOM-2922: [Forwardport] Remove leading Countrycode from EU-VAT-Numbers #17921

 - Merge Pull Request #17921 from mage2pratik/magento2:2.3-develop-PR-port-17385
 - Merged commits:
   1. 2bd17c0
   2. f1245e0
   3. a009dfe
   4. df4b935
   5. c4fc2ba
   6. 17161cf

Author: magento-engcom-team

app/code/Magento/Customer/Model/Vat.php

@@ -184,10 +184,15 @@ public function checkVatNumber($countryCode, $vatNumber, $requesterCountryCode =
 
             $requestParams = [];
             $requestParams['countryCode'] = $countryCode;
-            $requestParams['vatNumber'] = str_replace([' ', '-'], ['', ''], $vatNumber);
+            $vatNumberSanitized = $this->isCountryInEU($countryCode)
+                ? str_replace([' ', '-', $countryCode], ['', '', ''], $vatNumber)
+                : str_replace([' ', '-'], ['', ''], $vatNumber);
+            $requestParams['vatNumber'] = $vatNumberSanitized;
             $requestParams['requesterCountryCode'] = $requesterCountryCode;
-            $requestParams['requesterVatNumber'] = str_replace([' ', '-'], ['', ''], $requesterVatNumber);
-
+            $reqVatNumSanitized = $this->isCountryInEU($requesterCountryCode)
+                ? str_replace([' ', '-', $requesterCountryCode], ['', '', ''], $requesterVatNumber)
+                : str_replace([' ', '-'], ['', ''], $requesterVatNumber);
+            $requestParams['requesterVatNumber'] = $reqVatNumSanitized;
             // Send request to service
             $result = $soapClient->checkVatApprox($requestParams);