BR-AE-02 error EN 16931
BR-AE-02 — reverse charge without seller VAT ID
What it means
A reverse-charge invoice (category AE) shifts the VAT obligation to the buyer — but that only works if both parties are identifiable for VAT. The seller’s VAT identifier (BT-31) is therefore mandatory; its pair BR-AE-04 requires the buyer’s.
What triggers it
Any line or breakdown uses AE and seller.vatId is empty.
How to fix it
Set both parties’ VAT IDs:
{ "seller": { "vatId": "HU12345678" }, "buyer": { "vatId": "DE123456789" } } Use the EU VAT format (country prefix + number) and check the buyer’s ID in VIES before invoicing — an invalid buyer VAT ID invalidates the reverse charge itself, not just the XML. Free tool coming: /tools/vat-check/.
Check your invoice now. Paste it into the free validator — it flags BR-AE-02 and every other EN 16931, Peppol and XRechnung rule, each with the fix.
Or run the same check via API:
curl -X POST https://fakturwire.com/v1/validate \
-H "authorization: Bearer $FW_KEY" \
-d '{"invoice": { ... }, "profile": "en16931"}'