E-invoicing standard and Peppol: a practical guide
Electronic invoicing is becoming mandatory across the EU. This guide explains what a real e-invoice is, how Peppol and the EN 16931 standard work, and what is changing in each country.
What is an e-invoice (and what isn’t)?
An e-invoice is not a PDF or a scan. It is a structured, machine-readable file that another system can process automatically. Under EU Directive 2014/55/EU, it follows the European standard EN 16931.
EN 16931 defines a semantic data model, not a single file format. It is expressed in two official syntaxes: UBL 2.1 (used by Peppol, Belgium, Spain) and UN/CEFACT CII (used by France and Germany).
The main formats and networks
Most EU e-invoicing builds on the same European standard. The names differ per country:
| Peppol | A European network for exchanging e-invoices between organizations, supported by the European Commission. |
|---|---|
| EN 16931 | The core European semantic standard that the national formats all map to. |
| UBL 2.1 / CII | The two official XML syntaxes underneath the standard. |
| Hybrid (PDF + XML) | A human-readable PDF with the structured XML embedded, e.g. Factur-X / ZUGFeRD. |
Country mandates at a glance
Mandates and dates differ per country and are being phased in. The overview below reflects the official sources on the date shown; always confirm the current rules with the national authority before you rely on a date.
| Germany | Businesses must be able to receive e-invoices since 1 Jan 2025; the issuing obligation is phased in, applying to all domestic businesses from 1 Jan 2028. |
|---|---|
| France | In force since 1 Sept 2026: all VAT-registered businesses must be able to receive e-invoices, and large and mid-size firms must issue them. SMEs and micro-businesses must issue them from 1 Sept 2027. No automatic penalties during the start-up phase until the end of 2026. |
| Belgium | Structured B2B e-invoices via Peppol are mandatory between Belgian VAT-registered businesses since 1 Jan 2026. |
| Poland | KSeF becomes mandatory from 1 Feb 2026 for the largest taxpayers and from 1 Apr 2026 for the rest. |
| Spain | VeriFactu: invoicing software must comply from 1 Jan 2027 for companies (corporate income tax payers) and from 1 Jul 2027 for everyone else. B2B e-invoicing (Royal Decree 238/2026): mandatory 12 months after the ministerial order for the tax agency’s free public solution for businesses with turnover above €8 million, and 24 months after it for the rest. |
Official sources, checked on 6 Oct 2026:
- European Commission (eInvoicing / EN 16931)
- Bundesministerium der Finanzen (DE)
- economie.gouv.fr (FR)
- ksef.podatki.gov.pl (PL)
- FOD Financiën (BE)
E-invoice example: what is inside the file
An e-invoice under the EN 16931 standard is a list of defined data fields, each with a business term number (BT). The receiving system reads these fields directly, so nobody has to retype the invoice.
- BT-1 invoice number and BT-2 issue date.
- BT-27 seller name and BT-31 seller VAT identifier.
- BT-44 buyer name and the buyer reference or purchase order.
- Invoice lines with quantity, unit price and VAT category.
- BT-109 total without VAT, BT-110 total VAT and BT-112 total with VAT.
How Peppol e-invoicing works
Peppol uses a four-corner model. You send the e-invoice to your Peppol access point, which delivers it to your customer’s access point, which passes it to your customer’s system.
You do not need a separate connection with each customer. A Peppol ID per business is enough; the network looks up where to deliver it. Most invoicing software includes an access point, or connects to one.
How gofirmhub helps
Today you can create a clean PDF invoice for free with our invoice generator, for customers and countries where a PDF is still accepted. Where structured e-invoices are mandatory, you need e-invoicing software or the government’s own solution.
Open the free invoice generator
Frequently asked questions
Is a PDF invoice an e-invoice?
Not in the legal sense used by most EU mandates. A true e-invoice is a structured file (UBL 2.1 or CII) based on EN 16931, not a PDF.
What is Peppol?
Peppol is a European network for exchanging e-invoices and other documents between organizations, supported by the European Commission.
Do I have to send e-invoices now?
It depends on your country and customer. Rules are being phased in across the EU. Check your national authority for the exact dates.
What is the difference between e-invoicing and Peppol?
E-invoicing is the structured invoice itself, based on EN 16931. Peppol is one network for sending it. You can e-invoice without Peppol, but in Belgium, for example, Peppol is the default network for B2B e-invoices.
What is the e-invoicing standard in the EU?
The European standard is EN 16931. It defines the core data an e-invoice must contain; formats such as UBL and CII (used by Peppol, XRechnung and Factur-X) implement it.