Sending E-Invoices

The send endpoint generates a fully compliant XRechnung invoice from structured JSON data and delivers it as an email with the XML invoice attached. The recipient gets a professional email with both a human-readable HTML body and the machine-readable XML attachment.

Endpoint

POST /v1/invoices/send

Authentication

Authorization: Bearer ps_live_...

Request Body

{
  "from": "billing@yourdomain.com",
  "to": "invoices@customer.de",
  "format": "xrechnung-ubl",
  "invoice": {
    "number": "2026-0089",
    "issue_date": "2026-03-18",
    "due_date": "2026-04-17",
    "currency": "EUR",
    "seller": {
      "name": "Your Company GmbH",
      "street": "Hauptstr. 42",
      "city": "Munich",
      "postal_code": "80331",
      "country": "DE",
      "tax_id": "DE987654321",
      "contact_name": "Billing Department",
      "contact_email": "billing@yourdomain.com",
      "contact_phone": "+49 89 1234567"
    },
    "buyer": {
      "name": "Customer AG",
      "street": "Berliner Str. 10",
      "city": "Berlin",
      "postal_code": "10115",
      "country": "DE",
      "leitweg_id": "991-12345-67"
    },
    "payment": {
      "means_code": "58",
      "iban": "DE89370400440532013000",
      "bic": "COBADEFFXXX",
      "terms": "Net 30 days"
    },
    "line_items": [
      {
        "description": "Software license Q1 2026",
        "quantity": 1,
        "unit": "C62",
        "unit_price": "2400.00",
        "tax_category": "S",
        "tax_rate": "19.00"
      },
      {
        "description": "Implementation support",
        "quantity": 8,
        "unit": "HUR",
        "unit_price": "150.00",
        "tax_category": "S",
        "tax_rate": "19.00"
      }
    ]
  }
}

Response

{
  "id": "inv_a1b2c3d4",
  "email_id": "em_x9y8z7w6",
  "status": "queued",
  "format": "xrechnung-ubl",
  "validation": {
    "valid": true,
    "errors": [],
    "warnings": []
  }
}

The API validates the invoice data before generating XML. If validation fails, the response returns a 400 with the validation errors — the email is not sent.

Delivery Tracking

Track delivery status through the standard Postscale email events:

• email.queued — invoice email accepted for delivery
• email.delivered — invoice email delivered to recipient's mail server
• email.bounced — delivery failed (check bounce reason)

Use webhooks or poll GET /v1/emails/{email_id} for status updates.

Generated Email

The sent email includes:

• Subject: Invoice {number} from {seller.name}
• HTML body: clean, professional invoice summary with line items and totals
• XML attachment: fully compliant XRechnung/CII invoice (e.g., invoice-2026-0089.xml)
• DKIM signed: using your domain's configured DKIM keys

Unit Codes

Common UN/ECE Recommendation 20 unit codes:

Error Handling