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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.
Everything published here is on this page, grouped by the six sections the masthead numbers and written out in full in the HTML. Nothing is paginated, nothing is fetched by a script, and nothing is held back behind the filter: the box below narrows what is displayed, it does not decide what exists.
The site is organised around one argument, that mandatory e-invoicing in Europe is four separate problems usually discussed as one. There is the legal question of who is obliged, which is national and dated. There is the semantic question of what the document must contain, which is European and comparatively stable. There is the transport question of how it travels and who attests that it did, which is architectural. And there is the operational question of what a finance function has to change, which is where the money goes. The sections follow that division, so a piece that looks missing from one is usually deliberately in another: country timetables in mandates and deadlines, the model and the formats in standards and formats, delivery in networks and transmission, reporting in VAT and digital reporting, evidence and retention in integrity, signatures and archiving, and the project itself in implementation and operations.
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 12 min E-invoicing in Europe explained: the EU requirements and regulations, when e-invoicing becomes mandatory, and which national law actually obliges your business.
- Belgium's Structured Invoicing Obligation 5 min Belgium's B2B e-invoicing mandate has applied since 1 January 2026: structured invoices between Belgian businesses over an existing network, with no state platform.
- Derogations Under Article 395, and Why They Are Ending 5 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 6 min The EU e-invoicing directive, 2014/55/EU, obliges public bodies to accept invoices built to EN 16931 but obliges no supplier to send one. What it requires, and from when.
- France's E-Invoicing and E-Reporting Reform 5 min France's e-invoicing reform applies from September 2026: licensed platforms carry the invoice, and a separate e-reporting duty catches what invoicing does not.
- Germany's B2B E-Invoicing Mandate, Stage by Stage 5 min Germany's B2B e-invoicing mandate: every business has had to receive structured invoices since 2025, issuing follows in stages to 2028, and there is no central platform.
- Italy's SdI: What a Decade of Clearance Looks Like 6 min Italy's SdI exchange system has cleared domestic B2B invoices longer than any system in Europe. How it works, what an SdI code is, and what is still difficult.
- Poland's KSeF: A National Clearance System 5 min Poland's KSeF mandate routes every domestic B2B invoice through one state system, from February 2026 for the largest taxpayers and April 2026 for everyone else.
- Romania's RO e-Factura: Clearance Without a Pause 5 min Romania cleared every domestic B2B invoice through a state platform from 2024 and added consumer sales in 2025, on a European format and a tight timetable.
- 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 EN 16931 explained: the European e-invoicing standard's semantic model, its two syntax bindings and its validation rules, and what it deliberately leaves open.
- Business Terms and Business Groups: How to Read a BT Number 5 min What BT and BG mean on an e-invoice: the business terms and business groups of EN 16931, how a BT number is read, and the terms worth knowing by number.
- 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 CIUS narrows the European standard; an extension goes outside it. Why the difference decides whether an invoice that conforms to EN 16931 is still rejected.
- 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.
- Payment Instructions in EN 16931: BG-16 and Its Codes 5 min How a structured invoice tells the buyer how to pay — the payment means code, the account, the card and the mandate — and the handful of rules that reject a document when that part is wrong.
- 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 The four-corner and five-corner models are the two architectures of European e-invoicing. How each routes an invoice, who sees it first, and where each one fails.
- 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.
- Peppol Invoice Response: What Happens After Delivery 5 min The buyer's answer to a delivered invoice on Peppol: the seven status codes, what each commits the buyer to, and why the message is optional on the network.
- 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 What the Peppol network is: a governance framework for exchanging e-invoices through access points under common agreements, with no central operator in the path.
- Transmission Through the Italian Exchange System: Receipts, Rejections and Timing 6 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 The ViDA digital reporting requirements explained: what the VAT in the Digital Age directive changes for intra-Community trade, national regimes and the invoice.
- E-invoicing and E-reporting Are Two Obligations, Not One 6 min E-invoicing vs e-reporting: one governs a document passed between two companies, the other data sent to a tax administration about transactions that may have no invoice.
- Exemption Reason Codes: The Small Field That Rejects Large Invoices 5 min VAT exemption reason codes on an e-invoice: why a nil rate has to say why, and where the business decision, the code list and the national profile must agree.
- Hungary's Real-Time Invoice Reporting: The Regime That Went First 6 min Hungary's real-time invoice reporting sends invoice data to the tax administration as each invoice is issued. How its scope and schema grew, and what that teaches.
- Reconciling What You Reported With What You Filed 5 min VAT reconciliation once the administration holds your invoice data: why reported figures and the VAT return diverge, and how to make them agree before an audit does.
- SAF-T: One Schema, As Many Dialects as There Are Administrations 6 min What SAF-T is: the OECD standard audit file for tax, how European administrations adopted and changed it, and what producing one demands of your accounts.
- Self-Billing Under Mandatory E-Invoicing 6 min When the customer writes the invoice, a mandate's assumptions about who issues and who submits run backwards. What the VAT Directive allows and where it strains.
- 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 VAT determination moves to the moment of issue once the invoice is structured: place of supply, liability and category, forced into coded fields before sending.
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 Authenticity of origin, integrity of content and legibility: what the VAT Directive requires of every invoice from issue to the end of retention, and how to prove it.
- 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.
- Invoice Numbering: Series, Gaps and BT-1 5 min What Article 226(2) actually asks of an invoice number, why structured invoicing makes the choice of series hard to undo, and a worked design for several systems.
- 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 Invoice retention periods differ by country in Europe, and the VAT rule is rarely the longest one. How to work out the period that actually binds each document.
- 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 An e-invoicing readiness assessment worked in the order the answers bind: scope, documents, data, systems and the receiving side, ending in a defensible cost range.
- 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 6 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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