Need to restrict currency on purchase order based on invoicing currency

Summary:

We are looking to have some kind of warning or error or restriction when buyers attempt to create a purchase order in a currency that is different than the default invoicing currency for the supplier site.

Content (please ensure you mask any confidential information):

Some of our suppliers accept payments in different currencies under the same address and same bank account. We create two sites for these vendors but usually buyers end of using the wrong site. Ultimately, the PO needs to be updated that results in a lot of time lost.

If the system could warn the buyers with the message saying that this site has a different default currency that what you have selected for the PO, then this can be avoided.