# 📦 Download invoice as CII XML

Download an invoice as CII XML (EN16931 compliant).

Returns the invoice as a Cross Industry Invoice XML document that can be used
for e-invoicing in EN16931-compatible systems.

Args:
    invoice_id: The invoice ID (or draft_id) to export

Returns:
    CII XML document with application/xml content type

Endpoint: GET /invoicing/invoices/{invoice_id}/cii
Version: 1.0.0
Security: APIKeyHeader

## Path parameters:

  - `invoice_id` (string, required)

## Header parameters:

  - `X-PDP-Client-Id` (string, required)
    ID of the PDP Client for which the operation is performed

## Response 401 fields (application/json):

  - `error` (string, required)

  - `code` (integer, required)

  - `trace_id` (string, required)


## Response 200 fields

## Response 404 fields

## Response 422 fields