Because "What's the lawin', lass?" „Zahlen bitte!" « L'addition, s'il vous plaît ! » «Il conto, per favore!» «¿La cuenta, por favor?» «A conta, se faz favor!» „Poproszę rachunek!" "Notan, tack!" "De rekening, alstublieft!" «Τον λογαριασμό, παρακαλώ!» «Рахунок, будь ласка!» «Regningen, takk!» "Saisinko laskun?" „Fizetnék!" „Kontua, mesedez!" „Račun, molim!" "Hesap lütfen!" "Må jeg bede om regningen?" „Chönnti zahle?" "Could I get the bill?" should be an API call!
Developer-First E-Invoicing
E-Rechnungspflicht 2025 Ready

The E-Invoicing Engine for Developers

JSON in, valid PDF/A-3 out. Generate & validate elektronische Rechnungen. EN 16931 compliant.

Get Started Free Read the Docs
POST /v1/generate
200 OK 
{
  "invoice": {
    "number": "RE-2026-001",
    "seller": {
      "name": "Acme GmbH",
      "vat_id": "DE123456789"
    },
    "items": [{
      "description": "Consulting",
      "quantity": 8,
      "unit_price": 150.00
    }]
  }
}

rechnung-RE-2026-001.pdf

ZUGFeRD 2.3 • EN16931 • 42ms

Validated
ZUGFeRD 2.3
Factur-X 1.0
EN 16931
No Data Storage
GDPR Compliant
Made in Germany

Built for Modern Stacks

Generate EU-compliant e-invoices. No complexity, just a clean API.

Stateless by Design

Send JSON, receive PDF. No sessions, no stored data, no cookies. Your invoice data never touches our disk.

Privacy-First No Storage

Type-safe SDKs

Official client libraries for TypeScript, Python, Ruby, Kotlin, Java, Swift, Dart, and C#.

AI-Ready (MCP)

Native Model Context Protocol support. Let Claude, GPT, or your own LLM generate invoices directly.

9 Output Formats

ZUGFeRD, Factur-X, XRechnung, UBL, CII, Peppol, FatturaPA, plain PDF. Auto-detect or specify explicitly.

E-Rechnungs-Validator

Every PDF is validated against EN 16931 and KoSIT Schematron rules. Detailed errors with JSON-path references.

Always Free
E-Rechnungspflicht 2025

Bereit für die E-Rechnungspflicht

thelawin.dev generiert und validiert elektronische Rechnungen nach EN 16931. Unser integrierter Validator prüft ZUGFeRD, XRechnung und alle anderen Formate auf KoSIT-Konformität.

Mehr zur E-Rechnungspflicht
2025

E-Rechnungen empfangen

Pflicht für alle Unternehmen

2027

E-Rechnungen versenden (B2B)

Großunternehmen >800k€

2028

Pflicht für alle

Keine Ausnahmen

Interactive Demo

Try it Right Now

Edit the fields below and generate a real ZUGFeRD 2.3 PDF. Uses sandbox mode.

invoice.json
UTF-8
// Standard
// Seller
// Buyer
// Invoice
// Items
output.pdf
-- ms

No PDF generated yet

Click "Generate PDF" to create your invoice

Official Client Libraries

Type-safe SDKs for your favorite programming language. All auto-generated from our OpenAPI spec.

TypeScript
Python
Ruby
Kotlin
Java
Swift
Dart
C#

Missing your language? Let us know →

Simple, Transparent Pricing

Start free for development. Pay only when you go live.

1 credit = 1× /generate or /retrieve. /validate is free.

Sandbox

For development & testing

€0 /forever
  • 100 credits / month
  • All formats & profiles
  • "SANDBOX" watermark

Need production invoices?

€4.90 / 100 credits (no watermark)

Start Building
Recommended

Starter

For small businesses

€9.50 /month
€19 50% Beta
  • 500 credits / month
  • Production-ready output
  • Priority email support
Get Started

Pro

For growing teams

€24.50 /month
€49 50% Beta
  • 2,000 credits / month
  • Priority support
  • Custom templates
Get Started

All plans include full API access, all output formats, and detailed validation. Need more volume? Contact us for enterprise pricing.

Frequently Asked Questions

Common questions about thelawin.dev

What is thelawin.dev?

thelawin.dev is a Micro SaaS that serves as a drop-in replacement for EU-compliant e-invoicing. Send JSON via REST API, receive a valid PDF/A-3 with embedded XML.

Do you have a service or library somewhere in your infrastructure that creates PDF invoices from your data but isn't ready for EN 16931? thelawin.dev is your drop-in replacement.

Why do I need e-invoicing?

The EU mandates electronic invoicing for B2G (business-to-government) and increasingly B2B transactions. Germany: B2G since 2020, B2B receiving from Jan 2025, issuing from 2027. France: Sept 2026/2027. Italy: since 2019.

Think of the XML attachment as a "digital package insert" for your invoice – machine-readable, legally compliant, and required for doing business in the EU.

Who is this for?

Anyone who generates invoices programmatically:

  • Enterprises – Replace complex on-premise PDF libraries
  • SaaS providers – Add compliant invoicing to your platform
  • Freelance developers – Simple API, no infrastructure to maintain
  • AI agents – Native MCP support for Claude and other LLMs

The Micro SaaS approach means pay only for what you use, from 0 to 2,000+ credits/month.

How do you handle my invoice data?

We don't store it. Ever. thelawin.dev is truly stateless:

  • Your invoice data is processed entirely in RAM
  • PDF is generated and returned immediately as Base64
  • Nothing is written to disk, no database storage
  • Only usage counters (no content) are logged for billing

Billing via Paddle.com (Merchant of Record) ensures EU VAT compliance without us handling payment data.

Which formats do you support?

9 EU-compliant formats from a single JSON input:

* ZUGFeRD 2.3 – Germany B2B
* Factur-X 1.0 – France
* XRechnung 3.0 – Germany B2G
* Peppol BIS 3.0 – EU cross-border
* FatturaPA – Italy SDI
* UBL 2.1 – OASIS standard
* CII – UN/CEFACT
* Plain PDF – Non-EU regions

Use "format": "auto" and we'll pick the right one based on country codes.

How easy is the integration?

One POST request. That's it.

  • Test client built into this website – try before you code
  • Ruby SDK available now (gem install thelawin)
  • TypeScript & Python SDKs coming soon
  • OpenTelemetry support for monitoring and tracing
  • MCP server for AI agent integration

Most integrations take less than an hour.

Can I try it for free?

Yes, forever. The Sandbox plan is free with 100 credits/month.

  • Full API access to all 9 formats
  • Same validation and generation as paid plans
  • PDFs include a "SANDBOX" watermark
  • Perfect for development and testing
  • /validate is always free (doesn't use credits)

Why "thelawin"?

"Lawin" is Scots for "the bill" or "the tab" – as in "What's the lawin', lass?" It's our way of saying: asking for the bill should be as simple as an API call.

When does the e-invoicing mandate apply in Germany?

E-Rechnungspflicht timeline:

  • Jan 2025: All German businesses must be able to receive e-invoices
  • Jan 2027: Large businesses must send e-invoices (B2B)
  • Jan 2028: All businesses must send e-invoices

thelawin.dev supports both ZUGFeRD (B2B) and XRechnung (B2G) to ensure full compliance.

Is thelawin.dev KoSIT compliant?

Yes. All XRechnung invoices generated by thelawin.dev are validated against the official KoSIT Schematron rules (Koordinierungsstelle für IT-Standards).

This ensures full EN 16931 compliance and acceptance by German government portals like ZRE (Zentrale Rechnungseingangsplattform) and OZG-RE.

Does thelawin.dev support Chorus Pro (France)?

Yes. We generate Factur-X 1.0 invoices that are fully compatible with the French B2G portal Chorus Pro.

Important: France introduces mandatory e-invoicing (facturation électronique) in September 2026 for large enterprises, with full B2B coverage by 2027.

thelawin.dev generates PDF/A-3 with embedded CII XML, meeting all Factur-X EN16931 profile requirements.

Can I create FatturaPA invoices for Italy?

Yes. thelawin.dev supports FatturaPA 1.2.2 with all required fields for submission to the SDI (Sistema di Interscambio).

We handle Italian-specific requirements including:

  • Codice Destinatario – 7-character recipient code
  • Codice Fiscale – Italian tax ID
  • Partita IVA – VAT number formatting
  • PEC – Certified email address support

Does thelawin.dev offer an e-invoice validator?

Yes! The /validate endpoint validates e-invoices against EN 16931 compliance – and it's always free.

The validator supports:

  • ZUGFeRD 2.x – PDF with embedded CII XML
  • XRechnung 3.0 – UBL XML (KoSIT Schematron rules)
  • Factur-X – French standard validation
  • FatturaPA – Italian SDI format
  • Peppol BIS 3.0 – Cross-border EU invoices

Ready to Ship?

Generate your first EU-compliant e-invoice in under 5 minutes. No credit card required.

Start Building Free View Documentation