The library
Every article on the site
Grouped by section and numbered the way the masthead numbers them. Nothing is paginated and nothing is hidden behind a script: every link below is in the HTML.
01Mandates and Deadlines
Who has to issue a structured invoice, from what date, to whom, and under which national law.
- Mandatory E-Invoicing in Europe: What Is Actually Obligatory 9 min There is no single European e-invoicing mandate. There is one directive covering public procurement, a VAT directive that has just changed, and a growing set of national laws that do the real work.
- Belgium's Structured Invoicing Obligation 4 min Belgium mandated structured invoicing without building a platform, by naming an existing network as the default channel. It is the least original design in Europe and possibly the most sensible.
- Derogations Under Article 395, and Why They Are Ending 4 min For a decade, a Member State that wanted to mandate e-invoicing had to ask the Council for permission. That requirement shaped every national mandate in Europe, and it has now been removed.
- Directive 2014/55/EU: The Mandate That Started With Public Procurement 5 min The first European e-invoicing law obliged public bodies to receive structured invoices and obliged suppliers to send nothing. That asymmetry is why the European standard exists at all.
- France's E-Invoicing and E-Reporting Reform 5 min France did not build one platform. It licensed many, made them the counterparty, and attached a separate reporting obligation that catches transactions the invoicing mandate does not.
- Germany's B2B E-Invoicing Mandate, Stage by Stage 5 min Germany obliged every domestic business to be able to receive a structured invoice before obliging anyone to issue one, and it did it without building a central platform.
- Italy's SdI: What a Decade of Clearance Looks Like 5 min Italy has run mandatory business-to-business clearance longer than anyone else in Europe. The interesting part is not that it works, but which problems never went away.
- Poland's KSeF: A National Clearance System 5 min Poland routes every domestic business invoice through one state system, which assigns it a number. That number, not your own numbering, is what makes the invoice exist.
- Spain's B2B Mandate Under the Crea y Crece Law 5 min Spain legislated a business-to-business e-invoicing obligation and then made it wait for an implementing regulation, while two other obligations arrived in the meantime.
02Standards and Formats
The European semantic model, the two syntaxes that carry it, and the national profiles built on top.
- EN 16931: The European Semantic Standard for the Core Invoice 8 min A semantic model, two syntax bindings and a set of validation rules. Understanding what the standard fixes and what it deliberately leaves open is the difference between one integration and twelve.
- Business Terms and Business Groups: How to Read a BT Number 4 min A shared vocabulary that lets a tax administration, a software vendor and an accounts payable manager argue about the same field. Learning to use it saves more time than any other single thing.
- Code Lists, Identifiers and the Schemes Behind Them 4 min Automatic processing works because values come from published lists rather than from free text. Getting the lists right is unglamorous, cheap early, and ruinous late.
- Core Invoice Usage Specifications and Extensions 4 min A profile narrows the European standard; an extension goes outside it. The distinction sounds academic until an invoice that conforms to the standard is rejected for conforming to the standard.
- Factur-X and Hybrid PDF Invoices 4 min One file containing a human-readable PDF and a machine-readable invoice. It solves a real transition problem and creates one genuinely dangerous failure mode.
- FatturaPA: A National Schema, and the Cost of Having One 5 min Italy's invoice format predates the European standard and was built for a clearance system. It works. It also shows what a country pays for not adopting the common model.
- Peppol BIS Billing 3.0, and What a Network Profile Adds 4 min The most widely implemented European invoice profile is not a format. It is a restriction of the standard plus the rules that make delivery over a shared network possible.
- UBL and CII: The Two Syntaxes That Carry the European Model 4 min One semantic model, two XML syntaxes, and a genuine architectural decision hiding behind what looks like a file-format preference.
- XRechnung: Germany's National Profile, and How to Read One 4 min A national profile of the European standard, maintained by a public body, versioned on a fixed cycle. It is worth understanding as a specimen as much as for its own sake.
03Networks and Transmission
Four corners, five corners and the platforms in between: how a document actually gets delivered.
- Four Corners, Five Corners: The Two Architectures of European E-Invoicing 9 min Every European e-invoicing system is one of two shapes, and the difference decides who tells you an invoice failed, when, and whether you can do anything about it.
- AS4: The Transport Profile Underneath the Network 6 min Message-level security, a signed receipt, retry and an envelope that ignores the invoice. Each transport guarantee answers one business question precisely and leaves another wide open.
- Choosing an Access Point: The Questions That Decide It 6 min A procurement piece written by somebody who sells nothing. The questions that bind a provider decision, in the order they bind, and why the per-document price is rarely the one that matters.
- Peppol Addressing: How a Participant Identifier Becomes a Delivery 6 min An identifier resolves through a chain of lookups before anything is sent, and each link answers a different question. Knowing which link failed tells you who has to fix it.
- The French Partner Platform Model: Who Carries the Invoice and What the Administration Sees 6 min France routes the invoice through registered platforms that also file data about it. One registration covers both jobs, and the participant directory decides whether anything arrives.
- The Peppol Network: Participants, Access Points and Authorities 5 min A governed network rather than a product: who is allowed to carry documents, what they agree to, and why that agreement is the thing that actually makes interoperability work.
- Transmission Through the Italian Exchange System: Receipts, Rejections and Timing 5 min What happens between submission and delivery in a clearance model, and why the notification the platform returns is the only record of it that anyone else will accept.
- When Delivery Fails: Retries, Dead Letters and Who Carries the Risk 6 min A sent invoice and a received invoice are different facts. Five classes of delivery failure, who detects each one, who pays for it, and why retry logic only ever answers the first.
04VAT and Digital Reporting
Where the invoice data goes after it is issued, and what the tax administration does with it.
- VAT in the Digital Age: What the Digital Reporting Requirements Actually Change 11 min Three separate reforms travel under one name, and only one of them touches the invoice. This is what the reporting pillar does to intra-Community transactions and to national regimes.
- E-invoicing and E-reporting Are Two Obligations, Not One 6 min One obligation governs a document that passes between two companies. The other governs data sent to a tax administration about transactions that may never have produced an invoice at all.
- Exemption Reason Codes: The Small Field That Rejects Large Invoices 5 min Where a rate is nil, a structured invoice has to say why. That one field is where a business decision, a maintained code list and a national profile rule all have to agree.
- Hungary's Real-Time Invoice Reporting: The Regime That Went First 6 min Hungary has run an invoice data reporting obligation in production for years. The way its scope widened and its schema versioned is the part that transfers to every newer mandate.
- Reconciling What You Reported With What You Filed 5 min An administration receiving transaction data continuously holds a version of your position built from a different source. It will not match your return, and that is the job.
- SAF-T: One Schema, As Many Dialects as There Are Administrations 6 min The standard audit file is drawn from the ledger rather than from the invoice, which is precisely why it is the artefact most likely to contradict what you have already reported transactionally.
- Spain's Immediate Supply of Information: Ledger Data on a Short Clock 6 min The Spanish regime is routinely described as electronic invoicing and is nothing of the kind. It is register reporting on a working-day clock, and it turns reconciliation into a permanent job.
- VAT Determination When the Invoice Has to Be Right Before It Is Sent 6 min A structured invoice moves the determination decision forward to the moment of issue and forces it into coded fields. The rules did not change; the tolerance for not having applied them yet did.
05Integrity, Signatures and Archiving
Authenticity, integrity and legibility over a retention period measured in years, not months.
- Authenticity, Integrity and Legibility: The Three Properties an Invoice Must Keep 8 min The VAT Directive requires three properties of an invoice to be assured from issue to the end of retention, and leaves the method to you. What each one asserts is the point.
- Archiving a Structured Invoice: Keeping the Document, Not a Picture of It 6 min The obligation is to retain the invoice. Once it is a structured file, a stored PDF rendering does not discharge that, and the list of what to keep alongside it is long.
- Corrections and Credit Notes: The Invoice You Cannot Delete 5 min Once a document has been cleared or reported it exists in someone else's records. Which correction mechanism is available, and what each asserts, decides where the tax lands.
- Electronic Signatures and Seals: What eIDAS Actually Gives You 5 min A signature is made by a person and a seal by an organisation, and the tiers between them buy assurance about identity rather than better cryptography. What they cost is not the certificate.
- Invoice Data Is Personal Data: Where Data Protection Cuts Across the Mandate 6 min A mandate obliges you to create, transmit and retain data that identifies people. Data protection law obliges you to have a basis for each act and to stop when it runs out.
- Penalties: What the Mandates Threaten and What Actually Bites 6 min Penalty regimes attached to invoicing mandates come in a small number of shapes, and the shape decides where remediation money should go. It matters far more than the headline figure.
- Retention Periods Across Europe, and Why the Longest One Wins 6 min The VAT Directive leaves the retention period to each Member State, and the tax rule is rarely the longest obligation attached to the same document. Work out the rule, not the number.
- The Business Control Route: What a Reliable Audit Trail Has to Show 6 min Most businesses assure their invoices through business controls and could not describe how if asked. The route is free to adopt and expensive to evidence.
06Implementation and Operations
Master data, ERP readiness, supplier onboarding and the cost model that decides the approach.
- E-invoicing Readiness: The Assessment That Decides Everything After It 8 min Scope, documents, data, systems and the receiving side, worked in the order the answers bind. Done properly it produces a cost range you can defend line by line.
- Exception Handling in Week Three, When the Project Team Has Gone 5 min During a project, exceptions are worked by people with capacity and expertise. Three weeks after go-live they are not, and that is a capacity decision in technical clothing.
- In the ERP or at the Provider: Where the Integration Should Live 6 min This gets framed as build or buy, and it is really a question about where knowledge sits. Most large businesses end up splitting it, and the split has a cost that nobody puts in the comparison.
- Master Data: The Work Nobody Puts in the Business Case 6 min These projects fail on data, not on technology. The fields a structured invoice makes load-bearing were decorative before, and the difference between present and correct is where the whole cost sits.
- Onboarding Suppliers Without Two Thousand Separate Conversations 5 min When the obligation to receive arrives, every supplier has to be able to reach you. Contacting them all and asking for their details does not survive contact with a supplier base of any size.
- Redesigning Accounts Payable Around a Document That Arrives Structured 6 min On the receiving side a mandate deletes steps rather than adding them, and the control that used to sit inside those steps has to be put back somewhere deliberately.
- Testing Against the Validation Stack a Receiver Actually Runs 5 min Four gates stand between a document and acceptance and only three are published. Passing the public ones and failing the fourth in production is the normal project outcome.
- What a Mandate Costs: A Model You Can Argue With 6 min Licence and transaction fees are the visible cost and rarely the largest one. A business case built on price per document will be wrong in a direction that is discovered late.
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