PEPPOL-EN16931-F001: A date MUST be formatted YYYY-MM-DD

StandardPeppol BIS Billing 3.0 (OpenPeppol)SeverityError: the invoice is rejectedSyntaxUBL, CIIApplies 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-F001] A date MUST be formatted YYYY-MM-DD.

Why this error occurs

The value is present but does not match the required pattern: wrong date format, an IBAN with a wrong check digit, an e-mail address without a valid structure, a URL without scheme, or a text with forbidden characters.

How to fix it

Correct the value so it matches the format named in the rule: dates as YYYY-MM-DD in UBL and YYYYMMDD with format="102" in CII, IBANs without spaces and with a valid checksum, e-mail addresses with exactly one @, URLs starting with http:// or https://.

What the validator checks

Checked element (context):

UBL

cbc:IssueDate | cbc:DueDate | cbc:TaxPointDate | cbc:StartDate | cbc:EndDate | cbc:ActualDeliveryDate

Test (XPath):

string-length(text()) = 10 and (string(.) castable as xs:date)

CII

udt:DateTimeString

Test (XPath):

normalize-space(@format) = '102' and string-length(text()) = 8 and matches(normalize-space(text()), '20[0-9]{6}')

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

Frequently asked questions

What does PEPPOL-EN16931-F001 mean?

PEPPOL-EN16931-F001 is a peppol bis billing 3.0 rule: A date MUST be formatted YYYY-MM-DD.

Will my invoice be rejected because of PEPPOL-EN16931-F001?

Yes. PEPPOL-EN16931-F001 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-F001 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 and CII.

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