I'm curious to find out if it's possible to reject any payment transactions via AIM that do not supply a value for x_po_num. My company works with many 3rd party SaaS providers that use our authorize.net account to capture CC payments on websites they develop. We use the x_po_num field to store a unique internal identified so we know what the transaction is for and how to code it in our accounting system. From time to time a merchant will forget to send this and that causes havoc with our internal processes. Therefore, I'm wondering if we can cause authorize.net to reject any transaction which is missing a value for that field.
