A list of the complete business rules (BR = “Business Rules”) and business terms (BT = “Business Terms”) can be found in the official EU standard EN 16931.

The list of error messages is constantly being expanded.

An invoice containing an invoice item (BG-25) where the VAT category code of the invoiced item (BT-151) is “Intra-Community supply” must contain the VAT identification number of the supplier (BT-31) or the VAT identification number of the supplier's tax representative (BT-63) and the VAT identification number of the buyer (BT-48).

The invoice contains an invoice item that is taxed via reverse charge. At the same time, however, the VAT ID of the seller and/or buyer is missing, which is mandatory for EU tax cases.

The VAT ID of the buyer and/or purchaser must also be specified

The element “Buyer reference” (BT-10) must be transmitted.

Buyer reference (BT-10). An identifier assigned by the buyer and used for internal routing. The reference is defined by the buyer (e.g. contact details, department, office ID, project code), but is specified by the supplier in the invoice.

This error occurs with XRechnung if the buyer reference is not specified. XRechnung are the format of the public administration, which has given itself additional supplementary national business rules. XRechnung must always contain the buyer reference so that the public administration can send the invoice correctly internally. The public administration's buyer reference is the so-called routing ID. However, the field does not necessarily require a routing ID (only the public administration requires this for itself) and private companies do not have one.

This raises the question of why the supplier has sent an XRechnung to a private company if the format is intended for public administration.

Ask the supplier to include the buyer reference (e.g. the person who ordered, a department, etc.)

Or ask the supplier to send an e-invoice in ZUGFeRD format. In this case, the buyer reference is optional.