# ZUGFeRD and XRechnung Invoices

This article explains how to embed ZUGFeRD and XRechnung invoices in PDF documents with Telerik PdfProcessing.

The feature is available starting with `Q4 2025`.

[ZUGFeRD](https://de.wikipedia.org/wiki/ZUGFeRD) (acronym for Zentraler User Guide des Forums elektronische Rechnung Deutschland) is a specification for the electronic invoice format of the same name. `RadPdfProcessing` supports embedding ZUGFeRD invoices, including the XRechnung profile for German public-sector electronic invoicing compliance.

## Creating an Embedded Electronic (ZUGFeRD) Invoice

### Adding a ZUGFeRD Invoice

```C#
RadFixedDocument document = new RadFixedDocument();
using (RadFixedDocumentEditor editor = new RadFixedDocumentEditor(document))
{
    editor.CharacterProperties.TrySetFont(new FontFamily("Calibri"));
    editor.InsertRun("PDF/A-3B Compliant Invoice");
}

;
byte[] bytes = File.ReadAllBytes(@"zugferd-invoice.xml");
document.EmbeddedFiles.AddZugferdInvoice(bytes);

PdfFormatProvider provider = new PdfFormatProvider();
PdfExportSettings settings = new PdfExportSettings();
settings.ComplianceLevel = PdfComplianceLevel.PdfA3B;
provider.ExportSettings = settings;
using (Stream output = File.OpenWrite("exportedInvoice.pdf"))
{
    provider.Export(document, output, TimeSpan.FromSeconds(10));
}
```

> note Only a single XML invoice attachment is allowed according to the ZUGFeRD standard.

> important To comply with the PDF/A-3B standard, all the fonts in the documents must be embedded. Avoid using [Standard Fonts](https://www.telerik.com/document-processing-libraries/documentation/libraries/radpdfprocessing/concepts/fonts) because they are not embedded in the document. In **.NET Standard/.NET (Target OS: None)** environments, fonts beyond the [14 standard ones](https://www.telerik.com/document-processing-libraries/documentation/libraries/radpdfprocessing/concepts/fonts#standard-fonts) require a [FontsProvider implementation](https://www.telerik.com/document-processing-libraries/documentation/knowledge-base/pdfprocessing-implement-fontsprovider) to be resolved correctly.

### Removing a ZUGFeRD Invoice

```C#
if (document.EmbeddedFiles.ContainsZugferdInvoice)
{
    document.EmbeddedFiles.RemoveZugferdInvoice();
}
```

## Specifying ZUGFeRD Conformance Levels

Starting with **Q4 2025**, `RadPdfProcessing` supports specifying the ZUGFeRD (Factur-X) **conformance level** when exporting PDF invoices. Higher levels generally include all requirements of the lower levels and add more structured data to support automated processing and validation scenarios.

`RadPdfProcessing` allows you to set the `ZugferdConformanceLevel` when embedding the invoice. The available options are:

| Level       | Description                                                                                                                                                                                                                                  |
| ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `Minimum`   | The minimal profile providing only the essential data needed for a compliant e-invoice. Suitable for simple use cases with limited automation.                                                                                               |
| `Basic`     | The basic profile providing core structured data for improved interoperability and basic automated processing between trading partners. This is the default value.                                                                           |
| `Comfort`   | The comfort profile with richer structured content, typically aligned with common business requirements to enable advanced automation.                                                                                                       |
| `Extended`  | The most comprehensive profile including extended data elements to cover advanced or industry-specific scenarios beyond the comfort profile.                                                                                                 |
| `XRechnung` | The German CIUS (Core Invoice Usage Specification) reference profile based on EN 16931. Used for public-sector electronic invoicing in Germany. Exports with `XRECHNUNG` conformance metadata and embeds the invoice XML as `xrechnung.xml`. |

```C#
RadFixedDocument fixedDocument = new RadFixedDocument();
fixedDocument.EmbeddedFiles.AddZugferdInvoice(File.ReadAllBytes(@"zugferd-invoice.xml"), Telerik.Documents.Fixed.Model.EmbeddedFiles.ZugferdConformanceLevel.Comfort);
```

### XRechnung Profile

XRechnung is the German electronic invoicing standard mandated for public-sector invoicing. ZUGFeRD 2.1.1 defines an XRECHNUNG profile that enables XRechnung-compliant invoice data to be embedded in a PDF/A-3 document.

When you set the conformance level to `XRechnung`, `RadPdfProcessing` automatically:

* Sets the conformance level metadata to `XRECHNUNG` in the XMP metadata.
* Embeds the invoice XML with the filename `xrechnung.xml` instead of the default `factur-x.xml`.

```C#
RadFixedDocument document = new RadFixedDocument();
byte[] invoiceXml = File.ReadAllBytes("xrechnung-invoice.xml");

document.EmbeddedFiles.AddZugferdInvoice(invoiceXml, ZugferdConformanceLevel.XRechnung);

PdfFormatProvider provider = new PdfFormatProvider();
// Export as PDF/A-3B for ZUGFeRD compliance.
provider.ExportSettings.ComplianceLevel = PdfComplianceLevel.PdfA3B;
File.WriteAllBytes("output.pdf", provider.Export(document, TimeSpan.FromSeconds(10)));
```

> note When using the `XRechnung` conformance level, the embedded filename is fixed to `xrechnung.xml`. For all other conformance levels, the filename is `factur-x.xml`.

## Validating Documents

`RadPdfProcessing` follows the business-rule validation for ZUGFeRD and Factur-X XML published by the European Committee for Standardization: [Open-source E-invoice Validator](https://interoperable-europe.ec.europa.eu/collection/eprocurement/news/open-source-e-invoice-validator).

## See Also

* [Embedded File Streams](https://www.telerik.com/document-processing-libraries/documentation/libraries/radpdfprocessing/features/embedded-file-streams/embedded-file-streams)