PDF to Factur-X Transformation API Reference
Convert a PDF invoice into a Factur-X compliant PDF with embedded XML. The API extracts invoice data, maps it to the EN 16931 semantic model, and returns a PDF/A-3 with the structured factur-x.xml attachment.
This is an experimental feature. AI can make mistakes. Always double-check the result before submitting it to tax authorities.
https://api.invoicexml.com/v1/transform/to/facturx
Code Example
curl -X POST https://api.invoicexml.com/v1/transform/to/facturx \ -H "Authorization: Bearer YOUR_API_KEY" \ -F "[email protected]" \ -F "language=en"
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Request
| Parameter | Type | Description |
|---|---|---|
| file * | binary | The invoice file to process. |
| language | string | Language for PDF labels and date formatting. Values: en, de, fr. Defaults to en. |
Content-Type: multipart/form-data
The source and target formats are part of the endpoint path, and everything else (syntax, declared profile, specification identifier) is read from the document itself, so there is nothing more to configure.
Headers
| Header | Value |
|---|---|
| Authorization * | Bearer YOUR_API_KEY |
| Content-Type | multipart/form-data |
Response
200 Converted invoice
Returns the Factur-X PDF as a binary file.
Frequently Asked Questions
What is a Factur-X invoice?
Factur-X is a Franco-German e-invoicing standard (also known as ZUGFeRD 2.x in Germany). It embeds a structured XML file inside a PDF/A-3, making the invoice both human-readable and machine-processable.
What PDF formats are accepted?
The API accepts any standard PDF invoice. The conversion engine extracts invoice data using AI and maps it to the EN 16931 semantic model before generating the compliant Factur-X output.
Which Factur-X profile is generated?
By default the API generates a Factur-X EN 16931 (Comfort) profile, which covers the vast majority of B2B invoicing requirements in the EU.
How large can the PDF file be?
The API supports PDF files up to 20 MB. For larger batches, consider using the asynchronous conversion endpoint or splitting multi-page documents.
Is the output PDF/A-3 compliant?
Yes. The returned PDF conforms to PDF/A-3b and contains the embedded factur-x.xml attachment, fully meeting Factur-X specification requirements.