InvoicePayload

{
    "document_format": "xrechnung_ubl",
    "invoice_number": "RE-2026-001",
    "issue_date": "2026-04-07T00:00:00.000Z",
    "due_date": "2026-04-21T00:00:00.000Z",
    "delivery_date": "2026-04-07T00:00:00.000Z",
    "buyer_reference": "04011000-12345-03",
    "invoice_note": "Projektphase April 2026",
    "order_reference": "PO-2026-001",
    "payment_means_code": "58",
    "payment_terms_note": "Zahlbar bis 2026-04-21 ohne Abzug.",
    "currency": "EUR",
    "invoice_type_code": "380",
    "seller": {},
    "buyer": {
        "name": "Kunde GmbH",
        "company_supplement": "z. Hd. Einkauf",
        "street": "Hauptstr. 5",
        "postal_code": "54321",
        "city": "Hamburg",
        "country_code": "DE",
        "email": "buyer@example.com",
        "electronic_address_scheme": "EM",
        "contact_name": "Einkauf"
    },
    "branding": {
        "logo_url": "https://customer.example/logo.png"
    },
    "items": [
        {
            "name": "Webentwicklung",
            "description": "Implementierung und Review",
            "quantity": 10,
            "unit_code": "HUR",
            "price": 100,
            "tax_rate": 19,
            "service_period_start": "2026-04-01T00:00:00.000Z",
            "service_period_end": "2026-04-30T00:00:00.000Z"
        }
    ]
}