Slovenia FURS fiscalization

Full support for Slovenian fiscalization requirements (FURS).

FURS is separate from Slovenia e-invoicing. Use this guide for real-time fiscalization with the Slovenian tax authority. Use e-SLOG and UJP for Slovenian electronic invoice XML validation and UJP package downloads.

Prerequisites

Requirement	Description
Tax number	Entity with Slovenian tax number
Certificate	Digital certificate (.p12) from FURS

Setup

1. Upload Certificate

Upload FURS certificatetypescript

import SpaceInvoices from "@spaceinvoices/js-sdk/sdk";

const sdk = new SpaceInvoices("YOUR_API_KEY");

await sdk.fursSettings.uploadFursCertificate({
  certificate: fs.readFileSync("certificate.p12").toString("base64"),
  passphrase: "cert-password",
});

2. Register Business Premise

const _premise = await sdk.fursPremises.registerFursRealEstatePremise({
  business_premise_name: "PREMISE1",
  real_estate: {
    cadastral_number: "1234",
    building_number: "1",
    building_section: "1",
    community: "Ljubljana",
    city: "Ljubljana",
    street: "Main Street",
    house_number: "1",
    postal_code: "1000",
  },
});

If your FURS numbering strategy is centralized (C), you can pass starting_number when registering the premise. The first fiscal invoice for that premise-level sequence uses that value.

3. Register Electronic Device

await sdk.fursDevices.registerFursElectronicDevice("prm_123", { name: "DEVICE1" });

If your FURS numbering strategy is device-level (B), you can pass starting_number when registering the device. You can also update or clear a premise or device starting number with the PATCH endpoints, but only before any fiscal document counter has been created for that sequence.

4. Enable FURS

Enable FURStypescript

await sdk.fursSettings.update({ enabled: true });

Fiscalized Invoices

Invoices are automatically fiscalized when FURS is enabled:

Create fiscalized invoicetypescript

const _invoice = await sdk.invoices.create({
  items: [{ name: "Service", quantity: 1, price: 100 }],
  furs: {
    business_premise_name: "PREMISE1",
    electronic_device_name: "DEVICE1",
  },
});

By default FURS PaymentAmount equals InvoiceAmount. To report a smaller paid amount without changing the fiscal invoice total or taxes, set furs.payment_amount on POST /invoices or POST /invoices/custom. The value is in the document currency, from 0 through total_with_tax. Space Invoices converts it to EUR the same way as InvoiceAmount and applies credit-note sign server-side. Do not derive it from payments, total_paid, or total_due.

When a full credit note is created automatically by voiding or reissuing an invoice, it reverses the originally reported PaymentAmount, including an explicit zero. For example, an invoice reporting PaymentAmount €30 creates a reversal reporting −€30, even if the full invoice total is €100.

The ZZZS copayment case is a €100 invoice with a €30 patient payment:

{
  "InvoiceAmount": 100,
  "PaymentAmount": 30,
  "TaxesPerSeller": "calculated from 100"
}

Override FURS PaymentAmounttypescript

const _invoice = await sdk.invoices.create({
  items: [{ name: "Medical service", quantity: 1, price: 100 }],
  payments: [{ type: "cash", amount: 30 }],
  furs: {
    business_premise_name: "PREMISE1",
    electronic_device_name: "DEVICE1",
    payment_amount: 30,
  },
});

FURS returns confirmation data on the invoice:

Response Fields

eor

Unique invoice identifier from FURS

zoi

Protective mark (security code)

Invoices with non-cash payment methods (e.g., bank transfer) don’t require fiscalization:

Skip fiscalizationtypescript

const _invoice = await sdk.invoices.create({
  items: [{ name: "Service", quantity: 1, price: 100 }],
  furs: { skip: true },
});

QR Code

Fiscalized invoices include a verification QR code, embedded automatically in the PDF:

Render PDFtypescript

const _pdf = await sdk.invoices.renderPdf(invoice.id);