PEPPOL-EN16931-CL006: Invoice period description code must be according to UNCL…

StandardPeppol BIS Billing 3.0 (OpenPeppol)SeverityError: the invoice is rejectedSyntaxUBLApplies toInvoices and credit notes sent over the Peppol network (UBL) and, because XRechnung embeds the Peppol rule set, every XRechnung as well.

Official rule text

[PEPPOL-EN16931-CL006] Invoice period description code must be according to UNCL 2005 D.16B.

Why this error occurs

The element is mandatory in this standard but is missing or empty in your file. Typical causes: the field is not filled in the invoicing software, the ERP export does not map it, or the element is present but contains only whitespace.

How to fix it

Add the element with a non-empty value at the position given by the context above. Check the master data (seller, buyer, payment) in your invoicing software; most tools expose the field under the business term name shown here. Re-validate after the change.

What the validator checks

Checked element (context):

UBL

cac:InvoicePeriod/cbc:DescriptionCode

Test (XPath):

some $code in $UNCL2005
            satisfies normalize-space(text()) = $code

Check your invoice

Drop your XML or PDF on the validator and every failed rule is linked to its page here. Free, no account, the file is not stored.

Check your invoice →

Same check via API:

curl -F file=@invoice.xml https://einvoicechecker.com/v1/validate

Related rules

PEPPOL-EN16931-CL001 Mime code must be according to subset of IANA code list
PEPPOL-EN16931-CL002 Reason code MUST be according to subset of UNCL 5189 D.16B
PEPPOL-EN16931-CL003 Reason code MUST be according to UNCL 7161 D.16B
PEPPOL-EN16931-CL007 Currency code must be according to ISO 4217:2005
PEPPOL-EN16931-CL008 Electronic address identifier scheme must be from the codelist "Electronic Address…

Frequently asked questions

What does PEPPOL-EN16931-CL006 mean?

PEPPOL-EN16931-CL006 is a peppol bis billing 3.0 rule: Invoice period description code must be according to UNCL 2005 D.16B.

Will my invoice be rejected because of PEPPOL-EN16931-CL006?

Yes. PEPPOL-EN16931-CL006 is flagged "fatal"; validators (KoSIT, Peppol access points, the German ZRE/OZG-RE portals) reject the invoice until it is fixed.

Which formats does PEPPOL-EN16931-CL006 apply to?

Invoices and credit notes sent over the Peppol network (UBL) and, because XRechnung embeds the Peppol rule set, every XRechnung as well. Syntax: UBL.

Source: Peppol BIS Billing 3.0.20 (November 2025). Catalogue generated from the official schematron on 2026-10-14.

PEPPOL-EN16931-CL006: Invoice period description code must be according to UNCL 2005 D.16B