Invoices

Invoice Management

This section provides a comprehensive guide to managing invoices through the public API: creating and sending invoices with exact line details, reading them back with their VAT breakdown and payment state, adding payment transactions with the system's numeric payment-method codes, and cancelling invoices.

Invoice Operations

Create (and optionally send) an Invoice

  • Endpoint: /set_invoice
  • Description: Creates an invoice for an EXISTING customer (new customers must be registered first via the customer API calls). Every invoice line carries ALL of its own details — title, quantity, net unit price and VAT percent — whether or not it links an existing product via pid; the exact prices you send are the prices invoiced. Optionally pass send_methods (email, sms, einvoice — multiple allowed) and the invoice is delivered through every channel in the same call, with per-channel sent/error confirmations in the response.
  • Usage Notes:
    • The response includes the calculated totals, the VAT rows per VAT rate and the public payment link.
    • Invoices created via the API are created as Open under your own account credentials, exactly like invoices sent from the system.
  • Full Documentation and Practical Examples: Set Invoice



Fetch a Single Invoice

  • Endpoint: /get_invoice
  • Description: Fetch one invoice by numeric invoice_id or payment reference: header, status and flags, lines, VAT rows, totals, transactions, sent log, customer snapshot and the payment link.
  • Parameters:
    • invoice_id - The numeric invoice id (or reference).
  • Link To Documentation: Get Invoice via /get_invoice EndPoint



Add a Payment Transaction

  • Endpoint: /set_invoice_transaction
  • Description: Adds a payment transaction to an existing invoice. Payment methods are NUMERIC codes (0 bank transfer, 1 cash, 2 card, 3 online banking, 4 e-invoice, 5 paypal, 6 google wallet, 7 stripe, 20 cash on pickup, 21 cash on delivery, 25 factoring, 30 other, 100 customer balance credit transfer, 110 refund from invoice total) — the full map is documented on the endpoint page. Totals and status recompute automatically.
  • Link To Documentation: Add Transactions via /set_invoice_transaction EndPoint



Cancel an Invoice

  • Endpoint: /cancel_invoice
  • Description: Cancels an invoice by invoice_id or reference. Returns an error when the invoice already has payment transactions (the same guard the admin UI applies).
  • Link To Documentation: Cancel Invoice via /cancel_invoice EndPoint



For further assistance or API integration support, please refer to our API Documentation or contact our technical support team.