E‑Rechnungs-StudioE‑invoice made simple: XRechnung, ZUGFeRD, EN 16931
This short guide explains the core terms around e‑invoices — without jargon. If you want to start right away, upload a PDF and generate a verifiable e‑invoice with E‑Rechnungs‑Studio.
In 30 seconds
- An e‑invoice contains machine‑readable, structured invoice data.
- EN 16931 defines the European data model behind many formats.
- XRechnung is a German EN 16931 specification as XML.
- ZUGFeRD is a PDF with embedded EN 16931 XML.
Germany note: receiving has been required since 01.01.2025; issuing transitions run until 31.12.2026 or in some cases 31.12.2027. See the mandate timeline guide.
What is an e‑invoice?
An e‑invoice (E‑Rechnung) is more than a PDF. It contains structured invoice data in a standardized XML format. These data are machine‑readable: systems can automatically import and check amounts, taxes, line items and parties. The XML follows defined rules for mandatory fields, code lists and consistent calculations.
A PDF can still exist as a visual copy, but by itself it's not the structured e‑invoice. Depending on the format, the XML is sent as a separate file (for example XRechnung) or embedded in a PDF (ZUGFeRD).
What does EN 16931 mean?
EN 16931 is the European standard that defines which information an electronic invoice contains and how it maps to a common semantic data model. The goal is interoperability: invoices should be understood consistently across systems.
It covers data fields, relationships and business rules — for example totals, VAT, payment terms and references. Concrete formats and national profiles build on it. If an invoice is EN 16931‑based, it can be validated and processed automatically.
What is XRechnung?
XRechnung is a German specification for EN 16931‑based e‑invoices. Technically it's a CIUS (Core Invoice Usage Specification): it narrows down the European model and defines which fields are required, optional or excluded.
You often encounter XRechnung in the context of the German public sector. XRechnung is pure XML (no PDF) and is typically exchanged system‑to‑system. Validators check structure and business rules (mandatory fields, codes and totals).
What is ZUGFeRD?
ZUGFeRD is a hybrid invoice format: you get a regular, human‑readable PDF, and an EN 16931‑conform XML is embedded inside it. People can open the PDF as usual while systems automatically read and process the structured data.
This is useful when you need a visual invoice but still want machine‑readable data. In short: ZUGFeRD combines usability (PDF) and automation (XML) in a single file.
How E‑Rechnungs‑Studio helps
With E‑Rechnungs‑Studio, you can create a verifiable e‑invoice from an existing PDF:
- Upload PDF
- Generate XML
- Validate (review errors and warnings)
- Check the PDF preview
- Export and download ZUGFeRD
FAQ
Is a PDF invoice enough?
A PDF is primarily a human‑readable document. Many e‑invoice workflows rely on structured data so systems can import and check line items, taxes and totals automatically.
Whether a PDF is enough depends on the recipient and the process. If structured data is expected, a PDF alone often isn't sufficient.
Can I convert an existing PDF into an e‑invoice?
Yes. From an existing PDF, the relevant invoice data can often be extracted and structured as XML (for example XRechnung or ZUGFeRD XML).
In practice, a quick review helps: depending on layout, tables and fonts, automatic extraction can mix up details. E‑Rechnungs‑Studio shows you the results so you can verify and correct them.
What's the difference between XRechnung and ZUGFeRD?
XRechnung is a pure XML format. It only contains structured data and is typically exchanged directly from system to system.
ZUGFeRD is hybrid: the PDF remains as a human‑readable copy and the EN 16931‑conform XML is embedded inside it. People read the PDF while software processes the XML.
What does “validate” mean for an e‑invoice?
Validation means a validator checks the XML structure and the business rules: mandatory fields, code lists and calculation rules (for example totals, taxes and rounding).
The result is usually a report with errors and warnings that helps you make the invoice technically sound and internally consistent.
Why does a validator show errors and warnings?
Errors are clear rule violations (for example missing mandatory data or invalid codes) and usually prevent successful processing.
Warnings indicate potential issues that may still be acceptable depending on context. They are a prompt to double‑check before sending the e‑invoice.
What do I get at the end?
You get the generated structured invoice data as XML as well as the validation results. You can also check a PDF preview to verify the visual representation.
If you use ZUGFeRD, you'll get a ZUGFeRD PDF with embedded XML that works for both humans and systems.
What happens to my uploaded PDF?
The PDF is processed to recognize invoice data, generate a matching XML and (if needed) create a preview.
For details about data processing, see the privacy policy.
Do I need to know XML?
No. You don't need to write XML. E‑Rechnungs‑Studio generates the structure and shows validation hints so you can fix issues selectively.
If you can roughly place terms like e‑invoice, XRechnung, ZUGFeRD and EN 16931, reviewing results gets even easier — that's what this guide is for.