How do I fix UBL-CR-666?

Invoice Navigator automatically removes the disallowed `cbc:TaxExemptionReasonCode` element from your Invoice (UBL-CR-666). You can also use Invoice Navigator's automatic Fixer tool to correct this instantly.

Is UBL-CR-666 a critical error?

Yes, UBL-CR-666 is a critical error that will cause invoice rejection. It must be fixed before submission to ensure your invoice is accepted.

Can UBL-CR-666 be automatically fixed?

Yes, UBL-CR-666 can be automatically corrected. The fix is applied without modifying financial fields.

Error codes · UBL 2.1

UBL-CR-666In your invoicing software

Disallowed simultaneous reference to Invoice Object Identifier and Attachment

This is the rejection, word for word: „[UBL-CR-666] AdditionalDocumentReference shall not simultaneously contain both Invoice Object Identifier and Attachment“

What to have readyNothing. The file has to be re-exported from your invoicing software; we check it again afterwards.

What we doInvoice Navigator automatically removes the disallowed `cbc:TaxExemptionReasonCode` element from your Invoice (UBL-CR-666).

Choose the rejected invoiceor drop it here

XRechnung XML or ZUGFeRD PDF. Checking is free · corrected file €1.90 · the first every 30 days is free · no sign-up.

If you enter it yourself in your invoicing software

Before

<cac:TaxCategory>
  <cbc:TaxExemptionReasonCode>value</cbc:TaxExemptionReasonCode>
</cac:TaxCategory>

After

<cac:TaxCategory>
  <!-- cbc:TaxExemptionReasonCode removed for EN 16931 compliance -->
</cac:TaxCategory>

Element order is part of the rule: if the element sits in the wrong place, the validator rejects with UBL-CR-666.

What the finding looks likeExample

FindingStructure invalid · UBL-CR-666

Location/Invoice/cac:TaxTotal/cac:TaxSubtotal/cac:TaxCategory/cbc:TaxExemptionReasonCode

From youA re-exported file

ThenRe-export

ProofSHA-256 and /verify link after the check