SX
Saliox
HTML to PDF API for Templates, Invoices & Automated Workflows
Factur-X / EN16931 API

Generate Factur-X / EN16931 compliant invoice PDFs with embedded XML

Built for EU invoicing, ERP automation, AP systems, and public-sector procurement workflows. Create PDF/A-3 invoices with embedded EN16931 XML from hosted templates and billing data.

Compliance workflow

PDF/A-3 + embedded XML

EU-ready
Visual
PDF/A-3 invoice

Human-readable, archive-friendly invoice output.

Structured
EN16931 XML

Machine-readable invoice data embedded inside the PDF.

Delivery
Workflow ready

Send to S3, webhooks, portals, or downstream finance systems.

Human-readable
PDF/A-3 visual invoice for customers, finance teams, and auditors
Machine-readable
Embedded EN16931 XML for ERP ingestion and AP automation
Production ready
Generate from billing data and deliver automatically
Why this matters

Compliance-grade e-invoicing infrastructure, not just rendering

Factur-X support moves invoice generation beyond display rendering into finance, procurement, and automation workflows that require both a readable PDF and structured invoice data.

Finance-ready

EU-compliant invoice PDFs

Generate invoices designed for EU-facing finance workflows with PDF/A-3 output and embedded invoice XML.

ERP-ready

Automation-friendly structure

Support AP automation, ERP import, and procurement processes that require machine-readable invoice data.

Workflow-ready

Generate + store + notify

Combine hosted templates, billing data, S3 delivery, and async jobs to automate invoice delivery at scale.

Validate existing invoices

Validate existing Factur-X and PDF/A-3 invoice PDFs

Already have invoices coming from another ERP, billing system, or legacy workflow? Use the validate endpoint to check whether an existing PDF meets Factur-X / ZUGFeRD and PDF/A-3 compliance requirements before sending, storing, or handing it off to downstream systems.

Validate existing PDF invoices from external or legacy systems

Check Factur-X / ZUGFeRD structure and PDF/A-3 compliance

Return rule-by-rule validation results for automation and troubleshooting

{
  "pdf_url": "https://example.com/invoice.pdf",
  "profile": "facturx-en16931"
}
Typical output
• Compliance status
• Passed validation rules
• Failed validation rules
• Detailed feedback for remediation
View API docs
Best fit

Built for invoice workflows that need more than visual rendering

ERP and finance system integrations
Accounts payable automation
Public-sector procurement workflows
EU SaaS and billing platforms
Typical workflow
1. Build invoice template

Create a hosted invoice layout with your branding, totals, tax, and customer fields.

2. Send billing data

Inject invoice data, supplier data, customer fields, totals, and compliance values from your app.

3. Generate compliant output

Render a visual PDF/A-3 invoice while embedding EN16931 XML inside the document.

4. Deliver automatically

Store in S3, send through your portal, or trigger downstream webhook and finance workflows.

Example payload

Generate a compliant invoice from billing data

Use hosted templates plus structured invoice data to generate Factur-X compliant documents inside your invoice workflow.

Generate Factur-X / EN16931 compliant invoices from structured billing data and hosted templates. Send invoice fields, customer details, totals, tax values, and compliance data from your application, then produce a PDF/A-3 invoice with embedded XML as part of the same API workflow.

This helps teams turn billing data into finance-ready output without stitching together separate rendering, XML generation, and delivery steps. The result is a human-readable invoice for customers and teams, plus machine-readable data for ERP, AP, procurement, and downstream automation.

{
  "source": {
    "type": "template",
    "template_id": "invoice-default"
  },
  "options": {
    "format": "pdf",
    "page": { "size": "A4" },
    "compliance": {
      "factur_x": true,
      "profile": "en16931"
    }
  },
  "data": {
    "invoice": {
      "number": "INV-1024",
      "currency": "EUR",
      "total": "499.00"
    },
    "customer": {
      "name": "Acme GmbH"
    }
  },
  "delivery": {
    "type": "s3"
  }
}
Explore next

Start generating EU-ready invoice PDFs in minutes

Use hosted templates, structured billing data, and automated delivery workflows to generate compliant invoices at scale.