FiskHub API

Fiscalize a sale

One synchronous call. Request in, JIR out, typically in one to three seconds.

curl -sS https://api.fiskhub.com/v1/invoices \
  -H "Authorization: Bearer $FISKHUB_API_KEY" \
  -H "Idempotency-Key: 8f0b4e2a-6c31-4d9f-9a75-2b8e1c0d47f3" \
  -H "Content-Type: application/json" \
  -d '{
    "device_id": "6f1c0f9e-2b7a-4a56-9d3e-1f0b8a4c7d21",
    "occurred_at": "2026-08-27T10:32:11+02:00",
    "total": "4.50",
    "payment_method": "K",
    "vat": [{ "rate": "25.00", "base": "3.60", "amount": "0.90" }]
  }'

{
  "id": "inv_01J9Z4T7M2K8Q6R3V5X1Y0B2C4",
  "status": "confirmed",
  "jir": "2cf55235-9470-4b5c-a539-463f52b109d2",
  "zki": "e4d909c290d0fb1ca068ffaddf22cbd0",
  "qr_payload": "https://porezna.gov.hr/rn?jir=2cf55235-9470-4b5c-a539-463f52b109d2&datv=20260827_1032&izn=450",
  "number": "1041",
  "occurred_at": "2026-08-27T10:32:11+02:00",
  "total": "4.50",
  "currency": "EUR"
}

Before you write any integration code

The one branch that looks like a failure and is not

When the Tax Administration is unreachable, POST /v1/invoices still returns HTTP 200, with a zki, a ZKI-based qr_payload, status: "retrying" and jir: null.

The sale is legally valid. The ZKI and the QR payload are everything the device needs to print a compliant receipt. The device must complete the sale.

Read the full page before integrating →

Where to go next

Page	What it covers
Getting started	Base URL, API keys, test versus live, your first request.
Fiscalizing a sale	The POST /v1/invoices walkthrough, field by field.
Handling the no-JIR response	Start here if you read only one page.
Idempotency	Why Idempotency-Key is mandatory, and what double-fiscalization costs.
Status lifecycle	The five invoice statuses and which of them are terminal.
QR codes	Payload format and the printing requirements the regulation imposes.
Error taxonomy	Every error code, whether to retry, and the concrete fix.

What this API is, and is not

It fiscalizes B2C sales at unattended, self-service devices in Croatia, and nothing else.

There are no webhooks and no batch endpoint — fiscalization is synchronous, so neither has a job to do. eRačun (B2B invoicing) and eIzvještavanje are outside its scope. Poll GET /v1/invoices/{id} when you need to know whether a retrying invoice has since been confirmed.

/v1 never breaks. See versioning.