Hi, 

I use validationMode = liveMode when creating new payment profile. With this flag Authorize.net generates $0.00 test transaction for verification purposes. It works fine for Visa, Mastercard, but fails on every AMEX card we try. Still if you try to use card data directly to authorize payment it works. It seems to be something about the transaction that authorize.net generates to verify profile.

Here is the request (i replaced sensitive info) that is sent to api: 

<?xml version="1.0" encoding="UTF-8"?>
<createCustomerPaymentProfileRequest xmlns="AnetApi/xml/v1/schema/AnetApiSchema.xsd" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <merchantAuthentication>
      <name>XXXXXXXXXXXX</name>
      <transactionKey>XXXXXXXXXXXXXXXX</transactionKey>
   </merchantAuthentication>
   <clientId>sdk-dotnet-1.9.3</clientId>
   <customerProfileId>XXXXXXXXX</customerProfileId>
   <paymentProfile>
      <customerType>individual</customerType>
      <billTo>
         <firstName>Oleksandr</firstName>
         <lastName>Kozlov</lastName>
         <company />
         <address>XXX XXXXXXX XXX, XX</address>
         <city>Cincinnati</city>
         <state>OH</state>
         <zip>XXXXX</zip>
         <country>US</country>
         <phoneNumber />
         <faxNumber />
         <email />
      </billTo>
      <payment>
         <creditCard>
            <cardNumber>XXXXXXXXXXXXXXX</cardNumber>
            <expirationDate>2021-11</expirationDate>
            <cardCode>XXXX</cardCode>
         </creditCard>
      </payment>
   </paymentProfile>
   <validationMode>liveMode</validationMode>
</createCustomerPaymentProfileRequest>

The response:

<?xml version="1.0" encoding="UTF-8"?>
<createCustomerPaymentProfileResponse xmlns="AnetApi/xml/v1/schema/AnetApiSchema.xsd" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <messages>
      <resultCode>Error</resultCode>
      <message>
         <code>E00027</code>
         <text>This transaction has been declined.</text>
      </message>
   </messages>
   <validationDirectResponse>2,2,65,This transaction has been declined.,,Y,XXXXXXXXXXX,none,Test transaction for ValidateCustomerPaymentProfile.,0.00,CC,auth_only,none,Oleksandr,Kozlov,,XXX XXXXXXx XXX, XX,Cincinnati,OH,45220,US,,,email@example.com,,,,,,,,,0.00,0.00,0.00,FALSE,none,2E13813F21D24B02301F696ACF681E16,P,,,,,,,,,,,,XXXX1008,American Express,,,,,,,,,,,,,,,,,</validationDirectResponse>
</createCustomerPaymentProfileResponse>

Transaction details:

https://imageshack.com/a/img923/9888/zGJZY1.jpg

https://imageshack.com/a/img924/1493/jZptaz.jpg

For me it doesnt look like user is entering incoerrect CCV code. Because every single verification transaction failed and there were no successful transactions for AMEX.

Any thoughts on this?