In my case not always because restriction of Authorize.net. My client is a authorized weapons seller and Eprocessingnetwork.com allows him to process transaction where authorize.net does not. Eprocessingnetwork.com has a authorize.net emulator to process the transaction but I constantly getting the same error even after hard coding the AuthNet_PHP.php file to point directly to order.pl
Ln45 - curl_setopt($ch, CURLOPT_URL,"https://www.eProcessingNetwork.Com/cgi-bin/an/order.pl");
I am driving myself nuts trying to figure this out.