BT-20Payment termsBT-115Amount due for payment
Official rule text
[DE-R-018] Information on cash discounts for prompt payment (Skonto) shall be provided within the element "Payment terms" BT-20 in the following way: First segment "SKONTO", second segment amount of days ("TAGE=N"), third segment percentage ("PROZENT=N"). Percentage must be separated by dot with two decimal places. In case the base value of the invoiced amount is not provided in BT-115 but as a partial amount, the base value shall be provided as fourth segment "BASISBETRAG=N" as semantic data type amount. Each entry shall start with a #, the segments must be separated by # and a row shall end with a #. A complete statement on cash discount for prompt payment shall end with a XML-conformant line break. All statements on cash discount for prompt payment shall be given in capital letters. Additional whitespaces (blanks, tabulators or line breaks) are not allowed. Other characters or texts than defined above are not allowed.
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
(/ubl-invoice:Invoice | /ubl-creditnote:CreditNote)[$supplierCountryIsDE and $customerCountryIsDE]Test (XPath):
every $line in cac:PaymentTerms/cbc:Note[1]/tokenize(. , '(\r?\n)')[starts-with( normalize-space(.) , '#')] satisfies matches ( normalize-space ($line), $XR-SKONTO-REGEX) and matches( cac:PaymentTerms/cbc:Note[1]/tokenize(. , '#.+#')[last()], '^\s*\n' )
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.
Same check via API:
curl -F file=@invoice.xml https://einvoicechecker.com/v1/validateRelated rules
DE-R-001An invoice shall contain information on "PAYMENT INSTRUCTIONS"DE-R-002The group "SELLER CONTACT" shall be providedDE-R-003The element "Seller city" shall be providedDE-R-004The element "Seller post code" shall be providedDE-R-005The element "Seller contact point" shall be providedDE-R-006The element "Seller contact telephone number" shall be providedDE-R-007The element "Seller contact email address" shall be providedDE-R-008The element "Buyer city" shall be provided
Frequently asked questions
What does DE-R-018 mean?
DE-R-018 is a peppol national rule: Information on cash discounts for prompt payment (Skonto) shall be provided within the element "Payment terms" BT-20 in the following way: First segment "SKONTO", second segment amount of days ("TAGE=N"), third segment percentage ("PROZENT=N"). Percentage must be separated by dot with two decimal places. In case the base value of the invoiced amount is not provided in BT-115 but as a partial amount, the base value shall be provided as fourth segment "BASISBETRAG=N" as semantic data type amount. Each entry shall start with a #, the segments must be separated by # and a row shall end with a #. A complete statement on cash discount for prompt payment shall end with a XML-conformant line break. All statements on cash discount for prompt payment shall be given in capital letters. Additional whitespaces (blanks, tabulators or line breaks) are not allowed. Other characters or texts than defined above are not allowed.
Will my invoice be rejected because of DE-R-018?
Yes. DE-R-018 is flagged "fatal"; validators (KoSIT, Peppol access points, the German ZRE/OZG-RE portals, KSeF) reject the invoice until it is fixed.
Which formats does DE-R-018 apply to?
Only when the seller (or for some rules the buyer) is in the named country: the rule is triggered by the country code of the party. Dutch rules implement NLCIUS, German rules the XRechnung requirements inside Peppol. Syntax: UBL.
Source: Peppol BIS Billing 3.0.20 national rules (November 2025). Catalogue generated from the official rule sets on 2026-10-15.