# Source data readiness for e-invoices

- Updated May 2026

Use this checklist to make sure required invoice facts are present in source data before review, validation, and export.

## What this means

Structured e-invoices are accepted because the required invoice facts can be read from XML. A PDF image, note field, attachment, or internal ERP comment is not enough if the recipient or validator needs that fact as structured data.

Use this playbook before upload or API automation to decide whether the source invoice is ready for conversion plus validation, or whether someone must correct the source first.

## Fields to have ready

- Legal supplier and customer names, addresses, countries, and VAT identifiers when applicable.
- Invoice number, issue date, currency, invoice type, and buyer or order reference.
- Every line item with description, quantity, unit code, net unit price, line amount, VAT category, and VAT rate.
- Document-level discounts, charges, tax subtotals, total amounts, prepayments, and amount due.
- Payment means, IBAN or account details when paid by transfer, payment terms, and service or delivery period when required.

## Keep the structured part self-contained

For German B2B and many EN 16931 workflows, the practical baseline is that mandatory invoice information needs to be electronically readable in the e-invoice data. Do not rely on a human-readable PDF attachment or a side document to carry required facts that the XML does not contain.

Hybrid formats such as ZUGFeRD and Factur-X can include a PDF view, but the embedded XML still needs to match the reviewed invoice data.

## When to fix the source first

- The ERP export only has totals but not line-level tax categories or quantities.
- Buyer reference, Leitweg-ID, purchase order, VAT IDs, or payment terms live only in email text or portal notes.
- Attachments contain delivery periods, service descriptions, or discounts that are not on invoice rows.
- Multiple invoices, credit notes, deposits, or correction documents are combined into one file without a clear single invoice payload.
- Totals in the source data do not reconcile with the PDF or invoice ledger.

## Official reference

- [BMF FAQ on mandatory e-invoicing](https://www.bundesfinanzministerium.de/Content/DE/FAQ/e-rechnung.html): Use this as the German tax baseline, then verify the recipient channel, format, and validator results.

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