How does CASTiNET prevent duplicate vendor payments?
For any application, there can only be one transmittal to the vendor.
Once you "transmit" the application to the vendor, you don't want the application to change. That's why CASTiNET won't allow you to edit or void an application once it has been transmitted. You can't transmit an application to a vendor, then change the application and transmit it again because that would result in the vendor providing the service (fuel for example) more than once for the one application.
Instead, CASTiNET requires that the application be removed or "backed out" of the transmittal. CAAs can set who in the organization has the authority to do this. The assumption is that if they have this authority, they know that they need to contact the vendor to be certain that the service is correct and not duplicated.
This way, CASTiNET only allows an application to be transmitted to ONE vendor, ONE time, and prevents duplicate services.
What about payments?
The same logic applies to payments. For any application, it can only be on one payment batch to one vendor.
If you want to edit or void an application that has been placed on a payment batch, you must first remove the application from the payment, then you can edit it and place it on an payment batch. Like with transmittals, CAAs control who in the organization has the authority to perform this step.
When the CAA's finance staff reconcile the vendor's invoice to the payment batch, then it prevents a duplicate payment being sent to the vendor.
This process helps Finance ensure that duplication of transmittals, services and payments don't happen.
Keyword: payment transmittal edit void change