Credit Card Fraud Prevention Using .NET Framework in C#

One of the steps for merchant in order to prevent fraud is to check if the customer's IP address is same as what his or her billing address. In short, to check if the transaction is being requested by the real cardholder.

If you are looking for the C# sample code for IP address - billing country checking, see below.

Code:

Using IP2Location;
private void Query(string strIPAddress, string billingCountry)
{
  IPResult oIPResult = new IP2Location.IPResult();
  try
  {
    if (strIPAddress != "")
     {
      IP2Location.Component.IPDatabasePath = "C:\\Program Files\\IP2Location\\Database\\IP-COUNTRY.SAMPLE.BIN";
      oIPResult = IP2Location.Component.IPQuery(strIPAddress);
       switch(oIPResult.Status.ToString())
        {
          case "OK":
            if (oIPResult.CountryShort == billingCountry) {
              // buyer is from the same country by IP address
              } else {
              // buyer is from the different country by IP address
              }
          break;
           case "EMPTY_IP_ADDRESS":
                Response.Write("IP Address cannot be blank.");
                break;
           case "INVALID_IP_ADDRESS":
                Response.Write("Invalid IP Address.");
                break;
           case "MISSING_FILE":
                Response.Write("Invalid Database Path.");
                break;
           }
       }
       else
       {
        Response.Write("IP Address cannot be blank.");
       }
   }
    catch(Exception ex)
     {
      Response.Write(ex.Message);
     }
    finally
     {
      oIPResult = null;
     }
}