BR-DE-31Wenn "DIRECT DEBIT" BG-19 vorhanden ist, dann muss "Debited account identifier" BT-91 übermittelt werden.

Official rule text

If the invoice carries direct-debit data (BG-19), it must include the debited account identifier (BT-91) — the buyer's IBAN the payment is collected from.

Severity
Error
Applies to
CII, UBL
Rule set
v2026-08-31
Checked on

Written and checked against the official KoSIT rule set by Dmytro Yalanskyi, NormAPI.

Why does BR-DE-31 happen?

The customer's IBAN lives in the mandate at the payment provider or in the receivables master data, and is cautiously kept out of the invoice data set — but the rule requires it there. In CII it sits in a four-variable expression, the mirror image of BR-DE-30's: BT-91 is demanded as soon as any one of the three direct-debit fields appears. A document carrying only the payer's IBAN, with no mandate reference and no creditor identifier, fails BR-DE-31 all the same. Taken with BR-DE-30 that means, for CII: the creditor identifier and the payer's IBAN must both be present, while the mandate reference BT-89 stays optional.

What the validator checks

The expression the official KoSIT rule set evaluates — not paraphrased, but read from the Schematron file it ships. UBL and CII address different document trees, so the same rule reads differently in each.

UBL
not(cac:PaymentMeans/cac:PaymentMandate) or (cac:PaymentMeans/cac:PaymentMandate/cac:PayerFinancialAccount/cbc:ID)
CII
(($BT-89-path or $BT-90-path) and $BT-91-path) or $BG-19-not-existing

Variables in it

$BT-89-path
rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeSettlement/ram:SpecifiedTradePaymentTerms/ram:DirectDebitMandateID
$BT-90-path
rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeSettlement/ram:CreditorReferenceID
$BT-91-path
rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeSettlement/ram:SpecifiedTradeSettlementPaymentMeans/ram:PayerPartyDebtorFinancialAccount/ram:IBANID
$BG-19-not-existing
not(exists(($BT-89-path, $BT-90-path, $BT-91-path)))

Source: rule set v2026-08-31

How do you fix BR-DE-31?

Transmit the debited account's IBAN in BT-91: cac:PaymentMandate/cac:PayerFinancialAccount/cbc:ID in UBL, ram:PayerPartyDebtorFinancialAccount/ram:IBANID in CII. For IBAN correctness see BR-DE-20.

In the XML

A UBL fragment. The CII path is named above — same change, different element names.

Fails
<cac:PaymentMandate>
  <cbc:ID>MANDAT-2026-0007</cbc:ID>
</cac:PaymentMandate>
Fixed
<cac:PaymentMandate>
  <cbc:ID>MANDAT-2026-0007</cbc:ID>
  <cac:PayerFinancialAccount>
    <cbc:ID>DE02120300000000202051</cbc:ID>
  </cac:PayerFinancialAccount>
</cac:PaymentMandate>

Related rules

NormAPI provides technical validation, not tax or legal advice.