VAT Code Determination in PO

Hello All!

Can anyone help me to understand why SAP is automatically determine Vat Code D0 on my Purchase Order?

My supplier is VAT exempt; when I choose this supplier on the Purchase Order, automatically it fills the VAT Code at the item level with D0.

I've already check the settings related to VAT and I have nothing pointing to D0:

• Tax code Determination is empty;
• GL Account Determination window (Tax tab for Purchasing) as D3 for Items and D10 for Services;
• there are no VAT codes defined at GL Accounts Item.

Does anyone have any suggestion about the reason why is D0 picked when I chose these Supplier?

Thanks in advance for any help that you may provide