Need to create a supplier bank in the US for Netherlands supplier

We recently acquired a company in the Netherlands and required an extract of supplier and supplier banks.  During the creation of a vendor we were told that in NL they do not require bank account numbers that the IBAN is the account number for all in NL.  I found this to be true so in setting up the vendor, I entered the country Netherlands and by-passed the Bank Name and Branch Name. I entered the IBAN number and currency.  I eventually found the Bank Name and created a Branch so I could enter the BIC number.

The problem I am having is that the Account Number is a required field. I get the following error: