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Hub · 2026-05-16

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Validation playbooks from real conversion failures

Use these playbooks when a review or download error needs a concrete field-level correction.

What this section is for

These pages turn recurring production diagnostics and support cases into direct repair steps.

They do not replace the official EN 16931, XRechnung, or Factur-X rules. They explain what a user can safely change in the review step when a validator gives a terse business-rule error.

Playbooks

Start with the rule or symptom that matches the error message.

BR-CO-25: add a due date or payment terms

If the invoice amount due is above zero, EN 16931 needs a structured due date or clear payment terms before export.

Bank transfer: add IBAN, not direct debit fields

For payment means code 30, the seller IBAN is the required settlement account. Direct debit mandate fields belong to direct debit, not bank transfer.

PDF/A-3 and ZUGFeRD archive readiness

ZUGFeRD combines a PDF/A-3 container with embedded CII XML. The XML can be valid while the source PDF still fails archive checks.

VATEX and tax exemption reason errors

Tax-exempt invoices need a coherent VAT category, rate, and reason. An arbitrary VATEX code is worse than a clear reason text.

Review is current but download validation fails

The reviewed data and the downloaded artifact must be the same compliance object. If generation changes the object, final validation must stop the download.

Safe repair order

  1. Compare the reviewed value with the original PDF before editing.
  2. Prefer a missing source value over a guessed one; ask the issuer when the PDF is incomplete.
  3. Run review validation again after every material edit.
  4. Download only after the current review proof matches the selected output format.