EU E-Invoicing for Freelancers: ZUGFeRD, Factur-X & UBL

Picture this: a client in another EU country emails you in March 2027 and says, "We can't accept that PDF anymore. Send us a ZUGFeRD or a UBL file." If you're a freelancer, that one sentence is the entire e-invoicing story. The good news is simple — you really only need to learn two things: whether your client's country requires a structured e-invoice yet, and which file format it expects. Everything else is secondary.

This is the short version of e-invoicing for freelancers: what an e-invoice actually is, which EU countries have switched on a mandate and when, the format each one wants, and what a solo freelancer needs to comply — without hiring an accountant just to send a bill.

What "e-invoicing" really means (it's not a PDF)

A real e-invoice is a structured data file (XML, or a PDF with XML embedded inside it) that another system can read automatically, with no human retyping numbers.

The EU standard behind all of this is EN 16931. Every compliant national format is just a different flavour of that same standard. So when you hear ZUGFeRD, Factur-X, or UBL, you're hearing three local dialects of one shared language. That's good news for freelancers: you learn one structured invoice and export it in the dialect your client's country reads — six systems collapse into one.

Why is the EU pushing this? Two words: VAT fraud. Structured invoices let tax authorities see transaction data faster, eventually in near-real time. The umbrella reform is called ViDA (VAT in the Digital Age), adopted in March 2025, with cross-border B2B e-invoicing becoming the EU-wide default from 1 July 2030. This is not a fad you can wait out.

The EU e-invoicing mandate wave, country by country

Mandates are rolling out at different speeds, and the dates move, so always check your specific country before a deadline. Here's the rough map as of mid-2026. One thing to remember: most mandates start with a receive obligation (you must be able to accept e-invoices) before an issue obligation (you must send them).

Germany: All businesses, including freelancers, have had to be able to receive e-invoices since 1 January 2025. The obligation to issue them phases in: companies above €800,000 turnover from January 2027, then everyone else from January 2028. So most solo freelancers below that threshold must already accept e-invoices, and will need to issue them from 2028.

France: Phased from 1 September 2026: large and mid-sized companies must issue and report, and all businesses (freelancers included) must be able to receive e-invoices. Micro-enterprises and SMEs must issue from 1 September 2027.

Belgium: Live since 1 January 2026. All VAT-registered businesses must exchange structured B2B invoices. If you invoice a Belgian company, this affects you now.

Poland: The KSeF system went mandatory in phases through 2026: large taxpayers from 1 February 2026, most other businesses from 1 April 2026, micro-enterprises from January 2027.

Italy: The early mover. Mandatory B2B e-invoicing since 2019 via the FatturaPA format and the SDI clearance platform. If you bill Italian businesses, you're already in it.

Spain: The B2B mandate is now in law — the enabling Royal Decree (238/2026) was published in March 2026. The technical ministerial order is expected to take effect around October 2026, which starts the clock: larger firms (over €8m turnover) roughly a year later, everyone else about two years later.

Netherlands: No B2B mandate yet. Dutch use of structured invoices (UBL) is widespread and voluntary, and the government is tracking ViDA. A Dutch ZZP'er isn't forced today, but clients increasingly ask for UBL anyway.

Austria: No general B2B mandate (B2G with the public sector is a separate, older requirement). The Austrian format is ebInterface, and ViDA's 2030 date is the real horizon here.

Whether your country has a hard deadline or not, by 2030 structured e-invoicing is the EU baseline. Getting set up early is cheaper than scrambling the week your biggest client demands it.

Formats by country: the cheat sheet

Bookmark this table. The format depends on where your client is based:

Country	Format	What it looks like
Germany	ZUGFeRD / XRechnung	PDF with embedded XML (ZUGFeRD); pure XML (XRechnung, for public-sector)
France	Factur-X	The French twin of ZUGFeRD: a PDF with embedded XML
Netherlands / Belgium	UBL (Peppol BIS)	Structured XML
Spain	Facturae	Structured XML
Austria	ebInterface	Structured XML
Italy	FatturaPA	Structured XML via the SDI platform

A useful detail: ZUGFeRD and Factur-X are hybrid formats. The file is still a normal PDF you can open and read like always, but it carries the machine-readable XML inside. You keep a human-friendly invoice and satisfy the structured-data rule with one file. The pure-XML formats (UBL, Facturae, ebInterface) are meant to be read by software.

One thing worth clearing up, since it trips everyone up: Peppol is a delivery network — think of it as the post office, while the format is the letter inside. UBL is the format; Peppol is one common way to transport it. Plenty of freelancers will simply generate a valid UBL invoice and send or upload it the way their client asks, without touching the network themselves. (For a deeper look at each format, see our e-invoice formats guide.)

What e-invoicing for freelancers actually requires

Strip away the jargon and the to-do list is short.

1. Be able to receive structured e-invoices. If you have suppliers or subcontractors in a mandate country, they may already send you XML. You need to accept and store it. In Germany this receive-readiness has technically been required since 2025.
2. Produce the right format on demand. When a client asks for ZUGFeRD, Factur-X, or UBL, you should be able to hand it over the same day — not promise it "next week" while you Google how.
3. Get the VAT right. Cross-border B2B inside the EU usually means reverse charge (you invoice at 0% and note it), but only if your client's VAT ID is valid, which you check against the EU's VIES database. Get this wrong and the invoice is wrong. (Our EU VAT guide walks through reverse charge step by step.)
4. Keep the audit trail. Mandates expect invoices stored in their structured form for the legal retention period (commonly years), readable on request.

Notice what's not on the list: you don't need to file anyone's taxes, and you don't need to "join" a network to issue a basic e-invoice. You need correct data in the correct format.

This is exactly the gap we built Clozo to close for solo freelancers and micro-studios, because we got that "send us a ZUGFeRD" email ourselves and hated scrambling.

You build a proposal, get it e-signed (legally binding under eIDAS, with an audit trail of IP and timestamps), validate your client's EU VAT ID against VIES, apply reverse charge automatically for cross-border B2B, then export a valid e-invoice in the country format in one click: ZUGFeRD or Factur-X, a UBL/Peppol file, Facturae, ebInterface, or FatturaPA. No accountant required to send a single bill — see what's included. One thing to be clear about: Clozo produces the format file — it does not connect to or transmit through any national system. The actual submission or delivery — uploading to KSeF in Poland, Chorus Pro or a PDP in France, sending via SDI in Italy, or over the Peppol network — is something you (or your accountant) do with the file Clozo gives you. Clozo also doesn't do your tax filing. Clozo produces the valid format file — see pricing for the plans that include structured e-invoice formats. (You can start on the free plan, which covers proposals, PDF invoices and the legally-binding eIDAS e-signature.)

The one-line takeaway

You don't have to memorise eight national systems or panic about a deadline two years out. Find out which countries your clients are in, note their format from the table above, and make sure whatever tool you invoice with can spit out that format on demand with correct EU VAT. Set this up once, and the next time a client emails "we need a ZUGFeRD," you handle it in thirty seconds and move on.

Ready to make this a thirty-second job? Build your e-invoice with Clozo and have the right format ready before your next client asks — see pricing for the plans that include structured e-invoice formats.