When you are trying to process an online refund and a message box comes up saying "The "Refund was not successful", and the reason given is "Invalid Field". What this actually means is that the bank has refused to accept the refund, as per School Money support desk advice. It would be so much more helpful if the reason code actually stated " Refused by bank" or something similar. This would have saved days of waiting for a response from the support desk to confirm this.