E-invoicing in Slovenia: A Developer Guide

Overview

Slovenia uses the Peppol network for structured electronic invoicing, governed by the Financial Administration of the Republic of Slovenia (FURS — Finančna uprava Republike Slovenije). The national framework is built on Peppol BIS Billing 3.0 without a country-specific CIUS extension, meaning the OpenPeppol specification applies in full. Invoices flow directly between registered access points — FURS does not act as a clearance intermediary for B2B traffic.

The Slovenian VAT number format is SI followed by 8 digits (e.g. SI12345678). This identifier, stripped of the SI prefix, forms the basis of the Peppol participant ID using EAS scheme 9926. Slovenia adopted the euro at launch and all domestic commercial invoices are denominated in EUR.

Clearvo operates as a registered Peppol Access Point and handles all AS4 transport, SMP lookup, and UBL 2.1 generation for Slovenian transactions through a single REST API endpoint — no local tax engine or certificate management required on the integrator side.

Mandate and Timeline

Slovenia transposed EU Directive 2014/55/EU on electronic invoicing in public procurement and enforces Peppol-based delivery for B2G invoices. There is no confirmed date for a B2B mandate, though the EU ViDA (VAT in the Digital Age) framework is expected to create pressure for domestic B2B mandates across member states in the 2027–2030 window.

For B2G, Peppol delivery is the legally required channel. Paper and PDF invoices to Slovenian public entities are not accepted by FURS-registered recipients.

Format and Network

• Standard: Peppol BIS Billing 3.0 (EN 16931, OpenPeppol CIUS)
• Syntax: UBL 2.1
• Transport: AS4 via Peppol network
• Participant identifier scheme: EAS 9926 — Slovenian VAT number (8 digits, without the SI prefix)
• Currency: EUR
• Standard VAT rate: 22%; reduced rates 9.5% (food, books, medicines) and 5% (some cultural goods)
• Document types supported: Invoice (BIS Billing 3.0), Credit Note
• Routing: Clearvo performs a live SMP lookup against the Peppol network to resolve the buyer's access point before each send

No national CIUS or extension profile is published by FURS — the OpenPeppol BIS Billing 3.0 specification is sufficient for both B2G and B2B Peppol delivery in Slovenia.

Required Fields

The following fields are mandatory for a valid Slovenian Peppol invoice:

The buyerReference field (maps to BT-10 in EN 16931) is expected by most Slovenian public sector buyers and should be populated from the buyer's purchase order reference.

Integration Example

Send a Slovenian Peppol invoice via the Clearvo API:

curl -X POST https://api.clearvo.io/v1/invoices \
  -H "Authorization: Bearer $CLEARVO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "country": "SI",
    "documentType": "invoice",
    "invoiceNumber": "SI-INV-2026-001",
    "issueDate": "2026-06-16",
    "dueDate": "2026-07-16",
    "currency": "EUR",
    "buyerReference": "PO-2026-001",
    "supplier": {
      "name": "Clearvo Technologies Ltd",
      "taxId": "SI12345678",
      "taxIdCountry": "SI",
      "address": { "street": "Slovenska cesta 1", "city": "Ljubljana", "postalCode": "1000", "country": "SI" },
      "endpointId": "9926:SI12345678",
      "endpointSchemeId": "9926"
    },
    "buyer": {
      "name": "Slovenia Buyer AS",
      "taxId": "BUYERSI001",
      "taxIdCountry": "SI",
      "address": { "street": "Buyer Street 1", "city": "Ljubljana", "postalCode": "1000", "country": "SI" },
      "endpointId": "9926:BUYERSI001",
      "endpointSchemeId": "9926"
    },
    "lines": [
      { "description": "Software consulting services", "quantity": 5, "unitPrice": 1000, "taxCode": "S", "vatRate": 22 },
      { "description": "Platform subscription annual", "quantity": 1, "unitPrice": 3600, "taxCode": "S", "vatRate": 22 }
    ]
  }'

The response includes a Peppol message ID, AS4 delivery receipt timestamp, and the generated UBL 2.1 XML. Clearvo validates BIS Billing 3.0 rules and resolves the buyer's access point via SMP before transmission.

Key Rules

• EAS scheme 9926 only: Slovenia uses EAS code 9926 for Peppol participant identification. The VAT number in the endpointId must match the registered FURS VAT number — mismatches cause SMP lookup failures.
• VAT number format: The Slovenian VAT number is SI + 8 digits. Strip the SI prefix when constructing the endpointId value if your buyer's registered Peppol ID uses the numeric-only form; confirm via SMP lookup before first send.
• No clearance step: Slovenia does not use a government clearance hub. Invoices are delivered peer-to-peer via Peppol AS4. There is no FURS submission step, no government-issued invoice ID, and no real-time validation response from the authority.
• BIS Billing 3.0 strict compliance: OpenPeppol publishes schematron rules for BIS Billing 3.0. Clearvo runs these rules pre-send and rejects non-conformant payloads with a structured error response — fixing validation errors before transmission avoids undeliverable messages.
• No tax engine bundled: Clearvo does not calculate VAT or apply tax rules. Supply the correct vatRate and taxCode per line. For standard Slovenian supplies, use taxCode: "S" and vatRate: 22.
• Credit notes: Use documentType: "credit-note" with a precedingInvoiceReference field referencing the original invoice number and issue date. Credit notes follow the same BIS Billing 3.0 format and Peppol routing as invoices.

Related country guides

• Croatia — Peppol BIS 3.0, B2G mandatory
• Austria — Peppol BIS 3.0, B2G mandatory
• Slovakia — Peppol BIS 3.0, B2B mandate roadmap