e-SLOG 2.0 — national XML format since 2003

e-SLOG (eSlovenske informatike-Logaritmi) is an XML schema first published in 2003 by GZS (Gospodarska zbornica Slovenije — Slovenian Chamber of Commerce) in partnership with ZZI Zavod. Its originality: it wraps UN/EDIFACT INVOIC, ORDERS and DESADV messages in XML. This hybrid approach let Slovenian EDIFACT-heavy industrials (Krka, Gorenje, Mercator) move to XML without rewriting their business mappings. Version 2.0 aligned with EN 16931 since 2018.

History — from GZS 2003 to e-SLOG 2.0 EN 16931

Slovenia structured its B2B ecosystem around a national XML standard very early — one year before its EU accession (1 May 2004), and well before Directive 2010/45/EU set the foundations of European e-invoicing. The engine of this precocity was GZS (Gospodarska zbornica Slovenije), the Slovenian equivalent of a chamber of commerce, which co-funded with ZZI the e-SLOG programme as a competitiveness move: equip the Slovenian industrial fabric with a portable, free, EDIFACT-compatible EDI standard, fit for the Renault (Revoz), Mercedes, and Austrian/Italian distribution-chain partnerships.

Wrapping EDIFACT in XML was pragmatic: large industrials had already paid for EDIFACT implementations — imposing a divergent XML mapping was a non-starter. e-SLOG was born as an XML over-wrapper of EDIFACT INVOIC D.96A then D.01B (from 2008), XSD-validatable, transportable over HTTPS and SMTP, but preserving the business semantics that domestic ERPs already consumed.

2002       | GZS (Gospodarska zbornica Slovenije — Chamber of Commerce and
           | Industry) launches the e-SLOG programme (eSlovenske
           | informatike-Logaritmi) in partnership with ZZI Zavod
           | (Zavod za interno informacijsko podporo). Goal: equip
           | Slovenian companies with a unified e-business standard
           | ahead of EU accession in 2004.
           |
2003       | Publication of e-SLOG 1.0 — first XML schema wrapping
           | UN/EDIFACT INVOIC D.96A and ORDERS D.96A messages.
           | Strategic pivot: preserve the EDIFACT semantics already
           | used by Slovenian industrials (Krka, Gorenje, Mercator).
           |
2008-2012  | Mass adoption by Slovenian B2B. e-SLOG 1.5 published in
           | 2008 (upgrade to INVOIC D.01B). Network of local VANs
           | (ZZI, Halcom, Telekom Slovenije, Saop) integrating
           | automatic e-SLOG ↔ pure-EDIFACT conversion.
           |
2014       | e-SLOG 1.6 adopted by government decree as official B2G
           | format. UJP publishes its validation XSD. 1 January 2015
           | mandate confirmed.
           |
2018       | e-SLOG 2.0 — major overhaul aligned with European
           | standard EN 16931. Core Invoice Usage Specification
           | (CIUS) conformance. Official coexistence with PEPPOL
           | BIS Billing 3.0 on the UJP hub.
           |
2020       | e-SLOG 2.0.1 — harmonisation patch with PEPPOL BIS 3.0
           | evolutions (UNCL5189 codes, EN 16931 BT-references).
           |
2024-2026  | Stability. No major release planned before the ViDA
           | 2028 review. GZS communicates on e-SLOG durability as
           | a complement to PEPPOL — not a replacement.

Governance — GZS + ZZI + UJP

The format is co-governed. GZS (Gospodarska zbornica Slovenije) owns the functional spec and publishes the schema, user manual and examples on gzs.si. ZZI Zavod (Zavod za interno informacijsko podporo — institute for internal IT support) operates technical maintenance: XSDs, converters, online validators, and the main e-SLOG / PEPPOL transport network in Slovenia. UJP joined governance in 2014 when the format became official B2G, and publishes the integration constraints specific to the public hub.

A standing technical committee (Tehnični odbor e-SLOG) meets quarterly, with participation from the main operators (Halcom, e-Računi, Saop, Telekom Slovenije, Mikrocop). Any schema change goes through a public 45-day minimum comment call on gzs.si.

Technical schema — XML wrapping EDIFACT INVOIC

e-SLOG 2.0 is a single-file XML schema eSlogInvoice2.xsd published at gzs.si/skupne_naloge/e_poslovanje. It defines an <Invoice> root containing an M_INVOIC message structured as a UN/EDIFACT INVOIC D.01B UN, with segments S_UNH, S_BGM, S_DTM, G_SG2 (parties), G_SG26 (lines), S_MOA (amounts), S_TAX (VAT):

• S_UNH — INVOIC D.01B UN message header (mandatory).
• S_BGM — document type: 380 = invoice, 381 = credit note, 384 = correction (UNCL1001).
• S_DTM — dates: 137 = issue date, 35 = delivery date, 432 = due date.
• G_SG2 / S_NAD — parties: SE = seller, BY = buyer, DP = delivery party.
• G_SG26 / S_LIN + S_IMD + S_QTY + S_MOA + S_TAX — invoice lines: description, quantity, amount, VAT rate.
• S_MOA at document level — totals: 86 = incl. VAT, 79 = excl. VAT, 124 = total VAT.
• S_FII — banking details: IBAN SI56... + BIC.

<?xml version="1.0" encoding="UTF-8"?>
<Invoice xmlns="urn:eslog:2.00"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         Version="2.00">
  <M_INVOIC>
    <S_UNH>
      <D_0062>EDI-LJ-2026-04317</D_0062>
      <C_S009>
        <D_0065>INVOIC</D_0065>
        <D_0052>D</D_0052>
        <D_0054>01B</D_0054>
        <D_0051>UN</D_0051>
      </C_S009>
    </S_UNH>

    <S_BGM>
      <C_C002><D_1001>380</D_1001></C_C002>
      <C_C106><D_1004>2026/00917</D_1004></C_C106>
    </S_BGM>

    <S_DTM>
      <C_C507>
        <D_2005>137</D_2005>
        <D_2380>20260615</D_2380>
        <D_2379>102</D_2379>
      </C_C507>
    </S_DTM>

    <G_SG2>
      <S_NAD>
        <D_3035>SE</D_3035>
        <C_C082>
          <D_3039>5959876000</D_3039>
        </C_C082>
        <D_3036>Krka tovarna zdravil d.d.</D_3036>
      </S_NAD>
    </G_SG2>

    <G_SG26>
      <S_LIN><D_1082>1</D_1082></S_LIN>
      <S_IMD><C_C273><D_7008>Paracetamol 500mg blister 20 tabs</D_7008></C_C273></S_IMD>
      <S_QTY><C_C186><D_6063>47</D_6063><D_6060>120</D_6060></C_C186></S_QTY>
      <S_MOA><C_C516><D_5025>203</D_5025><D_5004>540.00</D_5004></C_C516></S_MOA>
    </G_SG26>

    <S_MOA><C_C516><D_5025>86</D_5025><D_5004>1220.00</D_5004></C_C516></S_MOA>
  </M_INVOIC>
</Invoice>

Comparison — e-SLOG vs Finvoice vs UBL PEPPOL

Adoption — 85% B2G, 70% large B2B

• ~85% of incoming UJP B2G flows are e-SLOG 2.0 (2024 estimate), ~15% in PEPPOL BIS 3.0. Stable since 2022, PEPPOL growing ~2 points/year.
• ~70% of Slovenian large-account B2B uses e-SLOG for domestic flows — adoption driven by Mercator (now Fortenova HR), Krka, Gorenje (Hisense Europe), Spar Slovenija, Petrol.
• ~5 major operators carrying e-SLOG traffic: ZZI Zavod (GZS reference), Halcom (corporate e-banking), e-Računi (cloud SaaS for SMEs), Saop (ERP Mikrocop), Telekom Slovenije.
• ~120,000 companies connected to the e-SLOG network through at least one operator — out of ~190,000 active companies according to AJPES.

Common pitfalls

• Thinking e-SLOG is pure EDIFACT. e-SLOG wraps EDIFACT in XML — HTTPS, SMTP or PEPPOL operator transport is XML. A partner expecting raw EDIFACT D.01B (without XML tags) will reject.
• Confusing version 1.6 and 2.0. 1.6 (still tolerated by UJP for legacy flows) is D.96A-based and not EN 16931 aligned. 2.0 is mandatory for any post-2018 partnership. Check the version in S_UNH/D_0054.
• Missing the urn:eslog:2.00 namespace. An e-SLOG XML without a namespace, or with the 1.6 namespace, gets rejected by ZZI and UJP validators. Common bug in home-grown ERPs.
• Wrong S_BGM/D_1001 code. 380 = commercial invoice, 381 = credit note, 384 = corrected invoice. Mixing 380 and 381 distorts FURS VAT returns.
• Swapping G_SG2 SE and BY. Seller (SE) issues, buyer (BY) receives. A flip breaks UJP routing and creates an orphan reception on the public-entity side.

Cross-links

• Slovenia hub — full view
• eRačun — B2G mandatory 2015
• UJP — public payments administration
• EDIFACT retail Slovenia
• Industrial EDI Slovenia
• GZS — e-SLOG spec
• ZZI Zavod — reference operator
• Halcom — corporate e-banking