Is IS-R-004 a critical error?

Yes, IS-R-004 is a critical error that will cause invoice rejection. It must be fixed before submission to ensure your invoice is accepted.

Can IS-R-004 be automatically fixed?

IS-R-004 requires a specific input value (e.g., a missing identifier or code). Provide the required data and re-validate.

Error codes · CIUS-IS · ISL

IS-R-004Fixable here

When both seller and buyer are Icelandic, the buyer's kennitala must be...

This is the rejection, word for word: „[IS-R-004] When both seller and buyer are Icelandic, the buyer's kennitala must be provided. This is required for domestic Icelandic transactions.“

What to have readyBuyer Kennitala

What we doThis requires user input to resolve. Review the relevant cbc: and cac: elements in your Invoice XML and provide the correct value. (IS-R-004).

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

<Invoice>
  <!-- Issue: When both seller and buyer are Icelandic, the buyer kennital -->
</Invoice>

After

<Invoice>
  <!-- Issue resolved per CIUS-IS (Iceland) -->
</Invoice>

What the finding looks likeExample

FindingValue missing · IS-R-004

From youBuyer Kennitala

ThenPassed

ProofSHA-256 and /verify link after the check

Often appears together with

IS-R-002Icelandic suppliers must provide their Icelandic legal ID (kennitala). This...IS-R-003Icelandic suppliers must provide complete address with street name and...IS-R-005When both seller and buyer are Icelandic, the buyer's address must include...