Freight invoices are the hard case of the German mandate.
Freight, tolls, demurrage, fuel surcharges, warehousing, customs, subcontractors: forwarder invoices combine many line items from many systems, and several of them are only known after the job. Self-billing (Gutschriftverfahren), the industry standard for paying carriers, explicitly falls under the mandate too, per the German Ministry of Finance decree of Oct 15, 2025 (para 17). And cross-border operators face parallel national systems like Romania's RO e-Factura and Poland's KSeF on top of the German rules.
One rebuilt pipeline instead of per-invoice patching.
A TMS update alone rarely closes the gap: format support varies by vendor and release, archiving (GoBD) usually needs a separate system, and self-billing plus surcharge logic live in your process, not in the format. We build the pipeline from order and consignment data to a validated, dispatched, archived e-invoice, and then operate it permanently.