R12 - How to determine which is the Primary bank account of a Supplier at the Site Level

Hi,

In Oracle11i, there is Primary check box at the Supplier Site form where the Supplier bank accounts are added. We check that box to indicate  the Supplier's Primary bank account. Sometimes a Supplier changes bank accounts and so there could be multiple bank accounts attached to the Supplier Site, but only 1 bank account is checked as the Primary.

When reviewing our converted supplier bank accounts into our R12 test system, I found IBY_ACCOUNT_OWNERS table showing the Primary_Flag, all set to Y, even for bank accounts that in 11i are not marked as Primary. 

Is there a different R12 supplier bank account table I should use to derive the true primary bank account of a Supplier at a Site Level?