Go to Basic > Setup >Addresses > Country/region
In this Form make sure the Country Region has VAT code. You can find that in General Tab. Once you defined the VAT code in this Country/Region form then you create your VAT Number.
Go to Basic > Setup >Addresses > Country/region
In this Form make sure the Country Region has VAT code. You can find that in General Tab. Once you defined the VAT code in this Country/Region form then you create your VAT Number.