00401

AliquotaIVA pari a zero senza Natura (riga di dettaglio)

What it means

On a detail line you set AliquotaIVA to 0.00 but did not specify a Natura code. SdI rule 00401: a 0% line must carry a Natura code that explains why VAT is not applied.

How to fix it

Add the appropriate Natura code (N1 escluse, N2.x non soggette, N3.x non imponibili, N4 esenti, N5 regime del margine, N6.x inversione contabile, N7 IVA assolta in altro Stato UE). If VAT should actually apply, set the real rate instead of 0.00.

# CLI
npx @eleata/validate-einvoice validate invoice.xml --format fatturapa

# GitHub Action — fail the build on any invalid invoice
- uses: hernaninverso/validate-einvoice-action@v1
  with:
    files: invoices/**/*.xml
    api-key: ${{ secrets.EINVOICE_API_KEY }}