A similar issue to UBL-468 was already known back in 2017.

At that time, for each card account:

• BT-87 (Payment card primary account number) was mandatory
• BT-88 (Payment card holder name) was optional

BT-87 : /Invoice(1..1)/cac:PaymentMeans(0..n)/cac:CardAccount(0..n)/cbc:PrimaryAccountNumberID(1..1)

BT-88 :
/Invoice(1..1)/cac:PaymentMeans(0..n)/cac:CardAccount(0..n)/cbc:HolderName(0..1)

In addition, UBL requires the presence of another sibling element, cbc:NetworkID, which must also be populated with a dummy value:

/Invoice(1..1)/cac:PaymentMeans(0..n)/cac:CardAccount(0..n)/cbc:NetworkID(1..1)