E-invoicing has solved delivery. Networks now move structured invoices and report tax data to administrations in near-real time, and mandates are making that the default: Belgium reached 88% business adoption within six months, France brought five to six million businesses into scope in September 2026, and under ViDA every intra-EU B2B invoice will be structured and reported by July 2030.
What none of it does is check whether the tax on the invoice is right.
Everything the ecosystem calls validation verifies that an invoice is well-formed: schema, business rules, code lists, arithmetic consistency. An invoice that applies the standard rate to a zero-rated supply passes every one of those checks, at every corner of the network, and now reaches the tax administration before anyone in the business has looked at it. Real-time reporting of wrong tax is not tax compliance; it is the faster distribution of errors.
This white paper documents that gap and explains why it persists. The root cause is semantic: the invoice never says, in machine-readable form, what is actually being supplied. In Europe the nature of the supply travels as free text, the classification field that exists is optional and rarely used, and no European or OECD initiative standardises classification on the invoice for tax purposes.
The argument rests entirely on the Peppol ecosystem’s own published record, including the complete session material of the Peppol Conference Europe 2026, some 580 slides in which tax correctness is addressed nowhere.
The paper covers the mandate landscape, what is checked at each corner of the five-corner model, why classification is the bottleneck, where a tax quality layer could live, and what standards bodies, tax administrations and service providers can each do next.
By Jan Druppel and Danny Vermeiren, Banqup Group. Deliberately vendor-neutral: it names no product and its recommendations stand independently of anything Banqup builds. Free to read, no registration.
