VAT in the Digital Age is one package, three pillars and a decade of deadlines. Here is what will bind you, what stays optional, and the 2030 and 2035 dates that reshape every cross-border roadmap.
Read article ArchitectureAdding the tax authority as a fifth corner is not a config change — it reshapes your send path, your error handling and your definition of "done". Here is what actually moves between the models.
Read article ReliabilityWhen the tax authority sits in your send path, its downtime becomes your incident. The regimes that plan for it define an offline mode; the ones that do not are where invoices pile up. How to build for both.
Read article SpecificationsThe happy-path invoice is the easy 80%. The credit note, the correction and the cancellation are where mandates diverge and integrations quietly fail. A field guide to the document types nobody scopes.
Read article ComplianceThe invoice is issued and cleared — and now you owe someone a readable, tamper-evident copy for the next decade. Retention periods, storage location, and integrity by signature versus audit trail: the part that is cheap to design and ruinous to retrofit.
Read article RoadmapThe mapping is rarely what makes a mandate late. It is knowing who your counterparties are, how they are identified, and whether they can receive at all. Why master data — not the format — is almost always the long pole.
Read article MandatesBefore scope, before format, one question sets your architecture: where does the tax authority sit relative to your invoice? The four control models, what each one costs to build, and the hybrids that catch people out.
Read article ValidationA passing validator is the start line, not the finish. The test layers a real go-live needs — conformance, the authority sandbox, the counterparty round-trip and the unhappy paths — and the order to build them in.
Read article SpecificationsFour different things get called "the e-invoicing standard", and mixing them up is the single most common reason an integration stalls. Here is the stack, from semantics to network.
Read article MandatesA mandate announcement is rarely a specification. These are the seven questions we work through first, and what each answer actually costs you in build effort.
Read article ValidationLocal validation is green, the tax authority or the receiver says no. Six places the gap usually hides, and the order to check them in.
Read articleHands-on utilities that run entirely in your browser — no login, nothing uploaded.
Open a UBL, Factur-X, XRechnung or FatturaPA file and read every EN 16931 field.
Open viewer →Generate well-formed Peppol BIS, XRechnung or Factur-X test XML.
Open generator →Check whether a company is on the Peppol network and what it can receive.
Open lookup →Ask it directly. If it is a good one, it usually becomes the next article.
