Invoicing

Overview

Ananas GDS includes a built-in B2B invoicing system for accommodation providers to bill tour operators and other partners. Invoices track line items, tax, due dates, and go through a structured lifecycle from draft to payment. PDF generation and email delivery are supported.

Invoice Model

The Invoice model represents a single billing document issued by an accommodation provider to a partner.

Invoice Line Items

Each invoice has one or more line items describing the services or goods being billed.

Line items are sent as a nested array in invoice create and update requests. Example request body:

{
  "partner": 42,
  "issue_date": "2026-05-01",
  "due_date": "2026-05-31",
  "currency": "EUR",
  "tax_rate": "19.00",
  "notes": "Season 2026 distribution fee",
  "line_items": [
    {
      "description": "Fact sheet distribution — Q2 2026",
      "quantity": "1.00",
      "unit_price": "450.00"
    },
    {
      "description": "Photo library sync",
      "quantity": "3.00",
      "unit_price": "50.00"
    }
  ]
}

Status Lifecycle

Invoices follow a strict state machine. The table below lists each status, its meaning, and the allowed transitions.

API Endpoints

Invoice CRUD

List all invoices for the authenticated user. Supports ?status= filter.

Create a new invoice. The invoice is created with status DRAFT . Include line items as a nested array in the request body.

Retrieve invoice details including line items and the full activity log.

Update an invoice. Only permitted when status is DRAFT .

Delete an invoice. Only permitted when status is DRAFT .

Invoice Actions

Transition the invoice from DRAFT to SENT . Sends a notification email to the partner.

Recipient marks the invoice as DISPUTED . Allowed from VIEWED or SENT .

Owner marks the invoice as PAID .

Cancel the invoice. Allowed from any non-terminal state.

PDF & Delivery

Download the invoice as a PDF. The PDF is rendered using the invoice's assigned template, or the default template if none is set.

Send a payment reminder email to the partner. See Reminders for details.

Templates

List all invoice templates for the authenticated user.

Create a new invoice template.

Retrieve a specific template.

Update a template.

Delete a template.

Invoice Templates

Templates customise the visual appearance and default content of generated PDFs. A template can be assigned to any invoice; if none is assigned, the platform default is used.

Activity Log

Every state change and action on an invoice is recorded in the InvoiceActivity log. The log is immutable — entries cannot be edited or deleted.

The full activity log is returned as a nested array in the invoice detail response ( GET /api/invoicing/invoices/{id}/ ), ordered oldest to newest.

Reminders

Payment reminders can be sent for invoices with status SENT , VIEWED , or OVERDUE . Each reminder dispatched is recorded in an InvoiceReminder record.

EU E-Invoicing (EN 16931)

To meet the German B2B e-invoicing mandate (receive since Jan 2025; issue by 2027 for >€800k turnover, all businesses by 2028), any invoice can be exported as a structured, standards-compliant e-invoice. This lives in an isolated module that reads invoices read-only -- it does not change how invoices are created, stored, or rendered.

Endpoint: GET /api/einvoice/{invoice_id}/?format=xrechnung (or zugferd ) -- returns the file as a download. Only the issuing or receiving company may fetch it. The legal fields EN 16931 requires but the company profile lacks (VAT-ID, IBAN/BIC, ISO country, electronic address) live on a dedicated EInvoiceProfile ; where blank they fall back to the company record.

Accounting CSV export: GET /api/einvoice/export/csv/?from=YYYY-MM-DD&to=YYYY-MM-DD returns the account's invoices (issued and received, optionally date-filtered) as a semicolon-delimited, BOM-prefixed CSV that opens cleanly in German Excel and imports into Xero / QuickBooks / most bookkeeping tools. The DATEV-specific EXTF Buchungsstapel export is a separate follow-on -- it additionally needs your chart-of-accounts numbers, so it is not emitted generically.

Inbound e-invoice receiver (Ananas as the hub): POST /api/einvoice/import/ accepts a structured EN 16931 e-invoice as the raw XML body -- in either syntax any compliant software emits: UBL (XRechnung) or UN/CEFACT CII (ZUGFeRD/Factur-X). Ananas parses it (invoice number, dates, seller/buyer with VAT-IDs, line items, tax and totals), stores it as an InboundEInvoice record (which also satisfies the legal requirement to be able to receive structured e-invoices), infers direction from your VAT-ID (issued vs received), and soft-links it to the matching platform invoice when one exists. This makes Ananas the server that holds the data, not just a client -- any external finance or partner system can push e-invoices in through one standards-based interface. (Auto-creating a full platform invoice from an off-platform counterparty is a reviewed follow-on.)

E-invoice inbox: GET /api/einvoice/inbox/ lists the account's received e-invoices (newest first; optional ?status=received|linked|error and ?direction=issued|received filters), and GET /api/einvoice/inbox/{id}/ returns the full detail including line items and the raw XML. In the app both live under Dev Tools → Connectivity → E-Invoicing , alongside a browser upload for the import endpoint and the accounting CSV download.