Fixture ID: noMeansCode · XPath: /ubl:Invoice/cac:PaymentMeans/cbc:PaymentMeansCode
The invoice carries a payment instruction group (BG-16), so it must specify the payment means type code (BT-81). BG-16 is optional in core EN 16931 — but once present it has to be actionable, and the means code is the part a payment system reads. An IBAN with no means code does not tell the payer whether you expect them to push a credit transfer or whether you intend to collect by direct debit, which are opposite instructions.
BR-49Set payment.meansCode to a UNTDID 4461 code: "58" SEPA credit transfer, "30" credit transfer, "59" SEPA direct debit, "48" bank card, "57" standing agreement, "97" clearing between partners. If you did not mean to give payment instructions at all, remove the payment object.
"payment": { "meansCode": "58", "iban": "DE02120300000000202051" }