An invoice has to be provable, not merely sent. The VAT Directive requires that the authenticity of its origin, the integrity of its content and its legibility are assured from the moment of issue until the end of the retention period, and it leaves the method to the taxable person. That choice is made once and then relied on for years, frequently by somebody who has since left.
This section sets out what each of the three properties requires, what evidence actually demonstrates them, and what it costs to keep that evidence usable over a decade. It covers electronic signatures and seals under eIDAS and the difference between the two, the business-controls route and the documentation it needs before it is worth anything in an audit, what a compliant archive has to preserve alongside the file, how long each Member State expects it kept, how corrections behave once documents are cleared or reported, and where data protection duties cut across the whole arrangement. Which law imposes the underlying obligation in each country is in mandates and deadlines; the format of the artefact being preserved is in standards and formats. The library lists every piece.
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.
The analysis underneath the anchor piece.
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.
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.
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.
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.
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.
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.
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.
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.
