Good day, @NDM06. I have information that explains why you're prompted to enter an SSN instead of a TIN in QuickBooks Bill Pay.
Please know that QuickBooks requires an SSN for Bill Pay instead of a TIN due to its integration with U.S. banking and financial systems, which cannot accommodate individuals with ITINs from different countries.
Also, it's correct that you can find a third-party application that can suffice this function. You can find one by visiting this website: Apps for QuickBooks Desktop.
For additional reference about QuickBooks Bill Pay, please see this resource: Learn about QuickBooks Bill Pay.
Also, check out this article if you want to be on track with the money you owe to your vendors: Accounts Payable workflows in QuickBooks Desktop.
Let us know if you have additional questions about entering TIN in your QuickBooks Bill Pay account. Just click the Reply button below. Stay safe always.