E-Invoice
An e-invoice is an invoice issued and transmitted in a structured, machine-readable format (usually XML per EN 16931, e.g. XRechnung or ZUGFeRD), so it can be processed automatically without any media break.
An e-invoice is an invoice that is issued, transmitted and received in a structured, electronic format, so its contents can be processed automatically without any media break. Unlike a PDF sent by email or a scanned paper document, a genuine e-invoice carries its details – invoice number, line items, tax amounts, payment data – as a machine-readable data set, typically as XML based on the European standard EN 16931. In Germany, an e-invoicing obligation has applied to domestic B2B transactions since 1 January 2025: every company must be able to receive and process e-invoices; the obligation to issue them is being phased in through 2028.
The key distinction is between image-based and structured invoices. A PDF is readable for humans, but to software it is initially just an image with no usable data structure. An e-invoice as defined by the standard delivers the data so that a receiving system can read, check and post it without manual entry. Since 2025, a plain PDF is therefore no longer an e-invoice under German VAT law but counts as an "other invoice".
At a glance
- Structured, machine-readable data set (XML) – not a PDF and not a scan
- Based on the EU standard EN 16931; common formats: XRechnung and ZUGFeRD
- Since 1 Jan 2025 in domestic B2B in Germany: receiving obligation for everyone
- Issuing obligation phased in by revenue through 2028 (transition periods)
- Enables automated, media-break-free invoice processing in the ERP
What sets an e-invoice apart from PDF and paper
The core of an e-invoice is its structured data set. Every detail sits in a defined field – service date, net amount, tax rate, IBAN, buyer reference. This lets software read the invoice without retyping, check it against the purchase order and goods receipt, and post it automatically in the accounts. A PDF or a scanned paper document carries the same information only as an image; a human has to read it, or text recognition (OCR) has to reconstruct it in a laborious and error-prone way.
Legally, the definition has tightened with the B2B obligation: in Germany, only an invoice issued in a structured electronic format that complies with the European standard EN 16931 (or an interoperable format) still counts as an e-invoice. Everything else – paper, PDF, JPG – is an "other invoice". This separation matters because the VAT obligations will in future be tied to the genuine e-invoice.
Structure and formats of an e-invoice
Technically, the e-invoice rests on a semantic data model: the standard EN 16931 defines which invoice contents exist and what they mean. This model is implemented in concrete syntaxes, in Germany mainly the XML standard UN/CEFACT CII and UBL. On this basis, two practically relevant formats have become established.
XRechnung – the pure XML format
XRechnung is a purely structured XML format maintained by KoSIT (the coordination office for IT standards) and is the German standard for invoices to public sector clients. It contains no visible visual representation; the invoice is transmitted solely as a data set and only prepared for display at the recipient when needed. XRechnung is thus maximally automatable, but not directly readable for humans without a viewer program.
ZUGFeRD – the hybrid format
ZUGFeRD combines both worlds: it embeds the structured XML data set into a PDF/A-3 file. The recipient sees a familiar PDF and can read it, while software simultaneously evaluates the embedded XML data automatically. From the ZUGFeRD profile "EN 16931" (Comfort) onwards, the format meets the standard and is recognised as an e-invoice. ZUGFeRD is especially widespread in B2B because it eases the transition from the PDF.
Legal framework and the B2B obligation from 2025
The starting point is EU Directive 2014/55/EU, which requires electronic invoicing to a uniform standard for the public sector. In Germany, this meant that since 27 November 2020 invoices to federal authorities (B2G) must be issued electronically. With the Growth Opportunities Act (Wachstumschancengesetz), the obligation was extended to domestic business-to-business (B2B) transactions and anchored in the VAT Act.
The rollout timeline
Since 1 January 2025, every domestic company must be able to receive and process e-invoices – this receiving obligation applies with no transition period. Transitional rules apply to issuing: until the end of 2026, paper and (with the recipient's consent) PDF invoices may still be issued, and for smaller companies with prior-year revenue up to 800,000 euros even until the end of 2027. From 2028, the e-invoice is in principle mandatory in domestic B2B. The whole thing is embedded in the EU initiative "VAT in the Digital Age" (ViDA), which envisages a digital reporting system in the longer term.
The e-invoice in the ERP system
For an ERP system, the e-invoice is both an outbound and an inbound topic. On the outbound side, the system generates a standard-compliant XRechnung or ZUGFeRD file directly from the sales document and transmits it – by email, portal upload or via a transmission network. Because the relevant data (customer account, line items, tax keys, payment terms) is maintained in the ERP anyway, the e-invoice arises with no extra effort, provided master data and tax logic are set up correctly.
The real efficiency lever lies on the inbound side: incoming e-invoices are read in automatically, matched to open purchase orders and checked in the invoice workflow (three-way match against purchase order and goods receipt). Approval, account assignment and hand-off to financial accounting or the tax adviser run largely without manual entry. Audit-proof archiving is important here: the e-invoice must be retained in its original format and in an unalterable way so that processing stays GoBD-compliant. Many systems handle this via a DATEV interface and an integrated document archive.
Distinctions: e-invoice, EDI and electronic invoice delivery
The term "electronic invoice" used to be understood broadly and also covered the PDF by email. That equation is outdated: an e-invoice in today's sense is necessarily structured. It must also be distinguished from classic EDI data exchange (such as EDIFACT), long used in trade between large partners. EDI can still be used, provided the invoice data obtained from it is interoperable with EN 16931.
There is no prescribed method for the transmission itself – email, customer portals, De-Mail or transmission networks are all permitted. Internationally, PEPPOL has become established here, a standardised network through which sender and recipient exchange e-invoices securely, without having to build bilateral interfaces. The e-invoice therefore describes the format of the document, not the transport route.
DACH specifics: Germany, Austria, Switzerland
Within the DACH region, the rules differ. In Germany, the B2B receiving obligation since 2025 is the most striking step; the main formats are XRechnung and ZUGFeRD. Austria has required electronic invoices to the federal administration since as early as 2014, usually via the Business Service Portal (USP) in the ebInterface format or as a PEPPOL invoice; there is no general B2B obligation there as in Germany.
As a non-EU country, Switzerland is not bound by the European rules. Electronic invoices to the federal administration are required above a certain contract value, and delivery via established invoice networks is common. Anyone invoicing across borders should therefore check which format and transmission route are required in the respective target country – an ERP with several e-invoice formats and a PEPPOL connection simplifies this considerably. This article provides a general overview and does not replace tax advice in an individual case.
Example
Example: B2B wholesaler switches to e-invoicing
A wholesaler mainly supplies business customers and previously issued PDF invoices by email. As of 1 January 2025, it sets up e-invoicing in the ERP: outgoing invoices are henceforth generated as ZUGFeRD, so customers still receive a readable PDF whose embedded XML data their systems post automatically. Customers who require pure XRechnung are served separately via a form rule.
In parallel, the trader activates e-invoice intake: supplier invoices in XML format are read in automatically, matched to open purchase orders and checked in the approval workflow. The documents land audit-proof in the archive and are handed over monthly to the firm via the DATEV interface. The result: less manual entry, faster use of early-payment discounts and a consistently auditable, GoBD-compliant filing system.
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