Proposals & Invoices · Article 5.6
E-invoicing formats: which one for which country, and why
EU member states are migrating to mandatory structured e-invoicing on different timelines. Clozo supports the six major formats — Peppol UBL, Factur-X, ZUGFeRD, FacturaE, KSeF, FatturaPA — with the right one auto-selected by the client's country.
"E-invoicing" used to mean "an invoice attached as a PDF to an email". Under the EU's Council Directive 2014/55/EU (B2G mandate) and individual member-state laws, it now means a structured machine-readable file that the receiving system can parse without OCR. Different countries picked different formats; the EU is gradually unifying them via Peppol. Clozo supports the major ones so you can comply per country without thinking about file formats.
Step by step
Set your Peppol participant ID
(one-time) at
/settings/payments→ Peppol section →Register. Pick the appropriate identifier scheme (typicallyiso6523-actorid-upis::0007:{your VAT ID}for most EU countries). Save.Add the client's Peppol ID
at
/clients/{id}→ Peppol section. If they don't know it, ask their accounting contact.When downloading
, click the format dropdown next to the invoice in the Documents dropdown. The recommended format for the client's country is at the top.
For automated routing
(Italy SDI, Poland KSeF, Spain B2G), Clozo handles the submission server-side when you click the right format. The result (confirmation, error) appears in the proposal Timeline.
For Peppol direct delivery
, Clozo submits the UBL to the Peppol network using your Access Point provider; delivery to the client's Access Point is typically 1–10 minutes.
format dropdown next to each invoice in the Documents area. Timeline events for each delivery attempt: "Submitted to KSeF — confirmation 2026/07/15-1234", "Sent via Peppol — message ID abc123", etc.
Why this works this way
The format landscape in 2026:
| Format | Country | Type | Mandate |
|---|---|---|---|
| Peppol UBL | Pan-EU (B2G universal; B2B optional) | Structured XML over Peppol network | B2G mandatory in most EU; B2B optional |
| Factur-X | France | Hybrid (PDF/A-3 + embedded UBL XML) | B2G mandatory; B2B mandatory from September 1, 2026 (large businesses) / September 1, 2027 (everyone else), PDP routing |
| ZUGFeRD | Germany | Hybrid (PDF/A-3 + embedded XML) | B2G mandatory since 2020 (Directive 2014/55/EU); B2B reception from January 1, 2025, issuance from January 1, 2027 / January 1, 2028 (small businesses) |
| FacturaE | Spain | XML signed with XAdES | B2G mandatory; B2B adopted (RD 238/2026) but not yet dated — 12 / 24 months from a ministerial order still unpublished |
| KSeF | Poland | XML uploaded to KSeF central portal | B2B mandatory from February 1, 2026 (largest taxpayers by 2024 sales) / April 1, 2026 (everyone else) / January 1, 2027 |
| FatturaPA | Italy | XML routed via SDI | B2B + B2G mandatory since January 1, 2019 |
Peppol UBL — the universal interchange. Peppol (Pan-European Public Procurement On-Line) is a network with standardised XML formats based on UBL (Universal Business Language). Every EU government accepts Peppol UBL for B2G invoicing. For B2B, Peppol is optional but increasingly common for cross-border. Clozo issues Peppol UBL with the client's Peppol Participant ID (a structured identifier like iso6523-actorid-upis::0192:991825827 for Norway, 0007:5567321707 for Sweden, etc.) — see article 6.7 for the network mechanics.
Factur-X / ZUGFeRD — the hybrid trick. Both Factur-X (France) and ZUGFeRD (Germany) are technically the same format (joint Franco-German standard, ISO 19005-3 PDF/A-3 with embedded UBL/UN/CEFACT CII XML). The PDF you can read normally; the embedded XML is parsed by the receiving accounting system. Clients without machine processing capability still see a normal PDF invoice; clients with automation grab the XML and skip OCR. This dual nature is why both DE and FR adopted it — it bridges the transition from human-readable to machine-readable.
FacturaE (Spain). XML format signed with XAdES (XML Advanced Electronic Signature) using a qualified certificate. Required for B2G and rolling out for B2B. Clozo generates the FacturaE XML unsigned. Applying the qualified-certificate signature is not something Clozo does today — you or your provider sign the file and deliver it through FACe (B2G) or Peppol (B2B). The signed XML is delivered through the Spanish FACe public-administration portal for B2G; for B2B, increasingly via Peppol.
KSeF (Poland). Krajowy System e-Faktur — Poland's central e-invoicing platform. Invoices are submitted to KSeF in a specific XML schema (FA(2), the second iteration of the schema). KSeF returns a confirmation number that becomes the legal "issue date" of the invoice. Mandatory for B2B from February 1, 2026 for the largest taxpayers and from April 1, 2026 for everyone else, with a further phase on January 1, 2027. Clozo generates the KSeF XML for you to download; uploading it to the KSeF portal and collecting the confirmation number are not handled by Clozo today — the client downloads the same XML separately or receives the confirmation reference via Peppol.
FatturaPA (Italy). Fattura Elettronica — Italy's mandatory structured XML format, routed via the SDI (Sistema di Interscambio) central exchange. Required since January 1, 2019 for B2B and B2G. Clozo generates the FatturaPA XML. It does not sign it and does not submit it to SDI — you submit through your own intermediary. A signature is not required for B2B invoices anyway, following the Agenzia delle Entrate ruling of 30 April 2018. SDI routes it to the recipient and returns success/failure codes.
How Clozo picks the format. When you generate an invoice, the Documents dropdown offers a Download as… choice with these options visible based on the client's country:
- Client in DE → PDF (default), Factur-X, ZUGFeRD, Peppol UBL. - Client in FR → PDF, Factur-X, Peppol UBL. - Client in IT → PDF, FatturaPA, Peppol UBL. (Note: for Italian B2B, FatturaPA via SDI is mandatory; PDF alone won't satisfy.) - Client in PL → PDF, KSeF XML, Peppol UBL. (From April 1, 2026, KSeF submission via the central portal is mandatory for B2B — from February 1, 2026 for the largest taxpayers.) - Client in ES → PDF, FacturaE, Peppol UBL. - Other EU → PDF, Peppol UBL. - Non-EU → PDF only.
The format suggestion is in the dropdown order — the first option is the recommended one for the client's country. You can override and pick PDF only if you've negotiated PDF delivery with the specific client.
Peppol Participant ID requirement. To send via Peppol, both parties need a Peppol ID. You can register one through Clozo's settings (one-time process, ~5 minutes); the client needs their own (their accountant or ERP provider usually has it). Without the client's Peppol ID, Peppol-routed delivery fails — fall back to PDF + email.
Troubleshooting
Keep reading
Proposals & Invoices
Peppol — IDs, network routing, error states
Peppol is the EU's universal e-invoicing network. Submit a Peppol UBL invoice via Clozo and it routes through your Access Point, the Peppol directory, the client's Access Point, and into their accounting system — usually within 1–10 minutes.
Refunds & Notifications
EU invoice compliance — Art. 226 mandatory fields, sequence numbering, retention
Every invoice Clozo issues complies with EU VAT Directive Art. 226: 14 mandatory fields, sequential numbering with no gaps, immutability after issue, and 10-year retention.
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The final invoice (INV-) — Schlussrechnung, facture de solde
The final invoice closes the project. It states the full work value, then explicitly references the deposit invoice and **deducts both the deposit amount and the deposit VAT**, so you don't pay tax twice. This deduction is mandated by §14 UStG and parallel rules across the EU.