Convert PDF to Factur-X using REST-API

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.

Try it out online — no coding required

Upload a PDF and get a compliant invoice back instantly, right in your browser.

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POST https://api.invoicexml.com/v1/transform/to/facturx

Request

Parameter	Type	Description
file *	binary	The PDF invoice file to convert.
strict	boolean	Defaults to `false`. When `true`, treat validation warnings as errors — the request is rejected if any warning is raised, not just errors.
version	string	Standard version (e.g. `2.3.2`). Defaults to the latest supported version.
profile	string	Compliance profile. Values: `minimum`, `basicwl`, `basic`, `en16931`, `extended`. Defaults to `en16931`.
syntax	string	XML syntax: `cii` (Cross Industry Invoice) or `ubl` (Universal Business Language). Defaults to `cii`.
embed	boolean	When `true`, embed the XML inside a PDF/A-3. Defaults to `true`.

Content-Type: multipart/form-data

Headers

Header	Value
Authorization *	Bearer YOUR_API_KEY
Content-Type	multipart/form-data

Response

200 Returns the Factur-X PDF as a binary file.

Content-Type: application/pdf

Code Example

curl -X POST https://api.invoicexml.com/v1/transform/to/facturx \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -F "[email protected]" \
  -F "version=2.3.2" \
  -F "profile=extended" \
  -F "syntax=cii" \
  -F "embed=true"

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.