BR-CO-09
A rule of the European standard EN 16931 – applies to every invoice following the standard, including Peppol BIS Billing 3.0.
What this error means
BR-CO-09
A VAT identifier lacks the two-letter country prefix (e.g. LT, PL, LV, DE).
How to fix it
Write the VAT number with its country prefix, e.g. LT100001919017 or PL7680002466.