Message configuration You must configure the Design Center Message to identify the country codes from the initial two characters of the VAT registration numbers. We also recommend that you verify that the source and destination countries are supported by TrustWeaver. In the Process configuration, you must add a legal statement, informing that the e-invoice has been issued by TrustWeaver AB on behalf of the Seller. In this section • Identifying source and destination countries. • Verifying source and destination countries. • Adding a legal statement.