Both answers are correct, and which one applies depends on which directive is asking. Under the VAT Directive, an electronic invoice is one issued and received “in any electronic format” — a PDF qualifies. Under Directive 2014/55/EU, which governs invoicing to the public sector, an e-invoice must arrive in a structured format that a machine can process on its own — a PDF does not qualify. The same file can therefore be a fully valid e-invoice when you email it to a customer and not an e-invoice at all when you send it to a public authority in the same country on the same afternoon.
That gap is not a drafting accident. It exists because the two laws are asking different questions, and it is scheduled to close on 1 July 2030 — earlier in the member states that have already moved.
The two definitions, side by side
Article 217 of the VAT Directive (2006/112/EC, as amended by Directive 2010/45/EU) defines an electronic invoice as one containing the information the Directive requires, issued and received in any electronic format. It says nothing about structure, syntax, or machine readability. A scanned image, an emailed PDF, an EDIFACT message, and a UBL XML file all sit in the same legal box.
Directive 2014/55/EU defines it differently: an invoice issued, transmitted and received in “a structured electronic format which allows for its automatic and electronic processing”. The Euro Retail Payments Board’s 2016 working group report spelled out what that phrase does in practice — the invoice has to enable fully digital processing with no human copy-pasting or retyping data. That is a technical test, not a legal-form test, and a PDF fails it.
Why the VAT rule ignores format
VAT law does not ask whether a machine can read your invoice. It asks whether you can prove the invoice is genuine and unaltered. Article 233 requires authenticity of origin, integrity of content, and legibility from the moment of issue until the end of the storage period — and it lets you satisfy that through business controls creating a reliable audit trail, an advanced or qualified electronic signature, or EDI.
Business controls are the low-tech option, and they are why PDFs pass. In Austria, for instance, the requirement is an internal control procedure with an audit trail — matching the invoice against existing business documents such as the purchase order. Nothing about that requires structured data.
The 2016 edition of the E-Invoicing and Retention in Europe compendium, compiled by Peters, Schönberger & Partner with local tax practitioners in each market, asked the same question in 22 European countries: does an electronic invoice have to be in a structured data format such as XML? Every one of the 22 answered no, and every one confirmed PDF or PDF/A was acceptable for both issuance and storage. The nuances were small: Hungary restricted formats to a whitelist (which included .pdf) and required a digital signature or EDI, Romania then required an extended digital signature based on a qualified certificate and noted XML and PDF were merely preferred, and the UK’s HMRC listed EDI, XML, comma-delimited ASCII and PDF as examples without mandating any.
Retention rules were the opposite of harmonised. The same compendium recorded periods ranging from five years (Greece, Poland) to eleven (Croatia), with Austria stretching to 22 years for immovable property and Belgium to 15 for investment goods. France added a format condition that still catches people: electronic invoices must be archived in their original format for three years, within an overall ten-year retention period.
Why the public-procurement rule doesn’t
Directive 2014/55/EU exists to make invoices flow into government finance systems without anyone rekeying them. It commissioned CEN to build EN 16931 — a semantic data model for the core elements of an invoice, with a list of compliant syntaxes (UBL and UN/CEFACT CII, both XML). Per the European Commission’s own compliance roadmap, all central contracting authorities had to be able to receive and process EN 16931-compliant invoices by 18 April 2019, with an optional 12-month extension pushing sub-central authorities to 18 April 2020.
Here is the caveat almost every summary skips: the Directive obliges the contracting authority to receive and process compliant e-invoices. It does not, by itself, oblige the supplier to send them. Whether you must issue structured invoices to the public sector is a question of national transposition — and many member states went further than the Directive required. Greece is the clear case: Law 4601/2019 (articles 148–154) transposed the Directive, and ministerial decision ΚΥΑ 63446/2-6-2021 then defined the national B2G invoice format, with GSIS acting as the national Peppol authority.
Legal but useless: what the format actually costs
The VAT-legal PDF and the structured e-invoice are separated by roughly an order of magnitude in processing cost, and the sources are unusually specific about it.
Billentis’s 2017 business-case report cites Finnish State Treasury estimates that an incoming paper invoice costs the receiving company 30–50 euros. Moving to electronic invoicing cuts that to about 10 euros with a semi-automated process — and to about 1 euro when the process is fully automated. The PDF lands you in the middle tier. The structured invoice is what buys the bottom one.
Why the middle tier is expensive is not mysterious. Under a scan-and-capture or image-based PDF workflow, Billentis reports that typically 20–30% of all invoices have to be handled as exceptions in one form or another, which is where the processing cost concentrates. When a recipient feeds an emailed PDF into the same capture pipeline it uses for scanned paper, the report notes the resulting data quality is only slightly better than with paper. The invoice arrived instantly and cost nothing to post — and then joined the same queue.
The report’s modelled recipient case (an industrial company with 5,000 employees, staff costed at 60 euros per hour) puts full paper processing at 17.60 euros per invoice against 6.40 euros for an electronic, automated flow — a 64% saving. On the issuing side the same case shows 11.10 euros against 4.50, or 59%. That distribution is the point Billentis draws out: the benefits of image-based PDFs sit mainly with the supplier, which is why larger recipients stay sceptical of them. Analysis from Politecnico di Milano, also cited in the report, put net benefits at 4–12 euros per invoice for VAT-compliant e-invoicing, rising to as much as 65 euros per cycle where the whole trade process is integrated.
These are 2017 figures; read them as a ratio, not a price list. The ratio is the argument. It is the same one behind Billentis’s estimate of a minimum 40 billion euro annual saving potential in Europe’s public sector, of which under 10% was then being exploited — an estimate whose model assumed 40% of e-invoices were unstructured PDFs and 60% structured XML, and which noted that administrations insisting on structured data only would do better.
What changes on 1 July 2030
ViDA — Council Directive (EU) 2025/516, adopted 11 March 2025 and in force since 14 April 2025 — resolves the contradiction by deleting one side of it. From 1 July 2030, Article 217 is replaced: an electronic invoice will mean one that, “at least in relation to the data referred to in Articles 262 and 271b”, has been issued, transmitted and received in a structured electronic format allowing automated processing. Recital 9 says plainly that this is being done to align the VAT definition with the one in Directive 2014/55/EU.
Four details matter more than the headline:
- Hybrid invoices survive. Recital 9 explicitly covers invoices that combine a structured part with an unstructured human-readable part, provided all reportable data sits in the structured part. ZUGFeRD and Factur-X are not casualties. PDF-only is.
- EN 16931 becomes the default, not the ceiling. The new Article 218(3) requires e-invoices to comply with the European standard, while letting member states allow other standards for domestic supplies outside the cross-border reporting scope.
- Consent disappears. Under the revised Article 232, issuing an EN 16931-compliant e-invoice to a taxable person will not require the recipient’s acceptance.
- The stakes rise from inconvenience to deductibility. ViDA lets member states provide that a customer may deduct or reclaim VAT only if it holds an e-invoice issued in the required format. At that point “legal but useless” stops being the failure mode; “not deductible” replaces it.
Two dates qualify the 2030 headline. Since 14 April 2025, member states no longer need a Commission derogation to mandate domestic e-invoicing — which is why the national mandates are arriving early. And member states that already had a domestic real-time transaction reporting obligation in place on 1 January 2024 have until 1 January 2035 to align those domestic systems.
Germany and Greece already flipped the definition
Germany is the cleanest illustration, because it changed the definition itself rather than bolting a reporting platform on top of the old one. Under the Wachstumschancengesetz, § 14 UStG redefined the electronic invoice with effect from 1 January 2025: a PDF sent by email is no longer an E-Rechnung but a sonstige Rechnung — an “other invoice”. The receiving obligation carried no transition period at all; every domestic business has had to be able to receive EN 16931-compliant invoices since 1 January 2025, and per the Federal Ministry of Finance’s guidance an email inbox is technically sufficient. Issuance is phased: paper and other electronic formats (with recipient consent) run through 2026, only businesses under 800,000 euros in prior-year turnover keep them in 2027, and from 1 January 2028 all domestic B2B invoices must be structured. In a hybrid invoice, the BMF’s October 2025 letter makes the structured part authoritative — and if the PDF layer disagrees with the XML, the divergent PDF can be treated as an additional invoice, with § 14c VAT liability attached.
Greece shows the same shift arriving through the tax-reporting door rather than the VAT-definition door. Authorised by Council Implementing Decision (EU) 2025/502, mandatory B2B e-invoicing went live on 2 March 2026 for businesses with over 1 million euros of 2023 revenue (penalties from 3 May 2026), with all remaining established businesses following on 1 October 2026. Invoices clear through myDATA, which returns a MARK and QR code — and an invoice never transmitted through the platform is not deductible for the buyer, regardless of whether the underlying transaction was real.
The pull-through effect was visible in Greece before either mandate. SAP’s August 2024 implementation guide for Greek e-invoicing records that once a company was issuing B2G invoices through a certified provider, the tax authority’s e-books rules forced it to submit all wholesale invoices — B2B included — through that same provider. The B2G requirement reached into B2B years ahead of the B2B mandate.
Set that against the 2016 compendium, where the Greek answer was the same as everyone else’s: no format required, PDF is fine. That answer was correct when it was written. It had an expiry date nobody printed on it.
Four things people get wrong
“PDFs are being banned”
No. Hybrid formats that embed structured data in a PDF container remain valid under ViDA, and member states can still permit other formats for transactions outside the reporting scope. What is ending is the PDF that contains nothing a machine can extract.
“It’s electronic, so it’s an e-invoice”
Only under Article 217 as it reads until 30 June 2030, and only where no national mandate says otherwise. In Germany that sentence has been wrong since January 2025.
“The B2G directive forces suppliers to send structured invoices”
It forces authorities to receive them. Your obligation to send comes from national law, which varies by country.
“An e-invoice is an e-invoice for both parties”
Not necessarily. Under the French rules recorded in the 2016 compendium, a recipient who printed an electronic invoice and deleted the data file was no longer holding an electronic invoice at all — on their side. Status can depend on what the receiver does after delivery, which is also why archiving the structured original matters: France requires the original format for three years, and Germany requires at least the structured part of an E-Rechnung to be kept intact.
Frequently asked questions
Is a PDF invoice legal in the EU?
Yes, for VAT purposes, under the current Article 217 definition — provided you can ensure authenticity of origin, integrity of content and legibility, typically through business controls with a reliable audit trail. That changes where a national mandate has already redefined the term, as in Germany since January 2025 and Greece for in-scope businesses since March 2026.
Does a PDF invoice need a digital signature?
Generally no. In the 22 countries surveyed in the 2016 PSP compendium, almost all answered that no digital signature was required where authenticity and integrity were otherwise ensured; Hungary (signature or EDI) and Romania (extended signature on a qualified certificate) were the exceptions of the time. Signatures are one permitted method under Article 233, not a requirement.
Is ZUGFeRD or Factur-X a PDF or an e-invoice?
Both, and that is the point. They are hybrid formats: a human-readable PDF carrying structured XML. ViDA’s recital 9 confirms hybrids fall inside the new definition as long as all reportable data is in the structured part. In Germany, the structured part governs if the two layers disagree.
Do I still need the buyer’s consent to send an e-invoice?
Today, yes in most cases — Article 232 makes electronic invoicing subject to recipient acceptance, though the 2016 compendium found that acceptance could usually be given tacitly, in Hungary even by simply paying the invoice. From 1 July 2030 consent falls away for EN 16931-compliant invoices issued to taxable persons, and member states have been able to remove it domestically since April 2025.
How long do I have to keep an electronic invoice?
There is no single EU answer. Periods in the 2016 compendium ran from five years to eleven, with longer terms for real estate and investment goods. Check the rule in each country where you are established or registered, and check the format condition as well as the duration.