I have a client that is using SIM and is running into an issue with their bank processing. Some of my client's users have multiple accounts on their system (husband & wife). In this scenario, the wife will log into her account and renew her membership, which processes fine. Next she logs out and logs in under her husbands account and renews his membership using the same card. This appears to process fine and no warning messages are received.
However, when my client goes to reconcile their account, their bank is only showing the first transaction. In discussions with their bank, the bank said that the reason for this is that the amount of time between payment requests was too short, so the bank is treating it as a duplicate payment request (even though 2 unique invoice numbers are being passed to Authorize.net).
I have been told that there is a way to slow down the amount of time that Authorize.net will send the request to the bank, but I am not sure what option that I should use for this. I found the x_duplicate_window setting, but I am not sure if this is what I should be using. If it is, should I be setting the value to a higher number or lower? If I set it higher, will the 2nd transaction fail if submitted in less time than the x_duplicate_window value or does this only apply to Authorize.net sending the transaction to the bank?