For example, I am in the UK. A supplier based in Germany only supplies a UK VAT number and an EORI number. They do not give their German VAT number.
I can't enter these in their account detail as the VAT country code (DE) is not editable. There is no place to enter an EORI number. Therefore I cannot enter the invoice correctly and have to make manual adjustments to the VAT return.
I suggest a dropdown which defaults to the code for the country of residence but can be changed if necessary, and to add an EORI entry field.