ZUGFeRD is convenient, well supported and easy to adopt. It is also delivered over the single most compromised channel in business computing, and almost nobody treats that as a design decision.
The delivery problem
ZUGFeRD invoices are typically sent as PDF attachments on email. That opens a door that has been well used for two decades. Criminals send fraudulent messages that look like legitimate invoices, and recipients open the attachment or follow the link because opening invoices is literally their job.
Three specific exposures
- Phishing. An invoice attachment is the most reliably opened file in any organisation. Attackers know this better than finance teams do.
- Insecure transmission. Because ZUGFeRD moves over email rather than a verified channel like Peppol, it is more exposed to interception, spoofing and tampering. Without additional controls, a business is one convincing message away from paying the wrong IBAN.
- Trust overhead. Companies relying on ZUGFeRD end up building their own verification layer — extra checks, extra approvals, extra people. That is an administrative cost imposed by the format choice, and it rarely appears in the business case.
Why XRechnung over Peppol is structurally different
XRechnung transmitted over the Peppol network sidesteps all three. Peppol provides encryption, validation and a standardised, verified process for moving invoices across Europe. The sender is known. The document is validated before it arrives. There is no attachment to open.
This is not an argument that ZUGFeRD is illegitimate — it is a valid format and there are good reasons to use it, particularly for B2B relationships where a human needs to read the document. It is an argument that the delivery channel is part of the security model, and treating it as a detail is how organisations end up defending a decision they never consciously made.
The question nobody is answering
Large corporates will build the controls to handle this. They have security teams and budget. What about the freelancer, or the twelve-person company, receiving the same attachment?
That asymmetry is the part of the e-invoicing transition that gets discussed least and will cost the most. The format debate is usually framed as convenience versus purity. It is closer to who can afford to defend themselves.
A version of this article first appeared on LinkedIn. Docnova handles Peppol delivery and fraud review before payment. Get in touch.