OltranoEN 16931 and Peppol
An e-invoice is not a PDF by email. It is structured data that a machine on the other side validates against a published rulebook — and rejects without reading if it fails.
Three layers, and people mix them up
- The format. UBL 2.1 or CII — the shape of the XML.
- The semantic standard. EN 16931 — what fields mean and the business rules they must satisfy.
BR-CO-17, for instance, says the VAT amount per category must equal the taxable base times the rate, rounded to two decimals. - The network and the national rules. Peppol BIS 3.0 to move it, plus whatever your country adds — a national tax ID format, a mandatory buyer reference, a specific code list.
A file can be valid UBL and still fail EN 16931. It can pass EN 16931 and still be rejected by a national rule. Each layer has to be satisfied separately.
What Oltrano does
Every invoice can be produced as EN 16931 UBL. Where the country has a national system, we speak to it directly rather than handing you a file: fifteen providers are implemented across fourteen jurisdictions. What a given country does — who allocates the number, whether the invoice must be cleared before it is sent, what happens to corrections — is different in each, and is written up on the country pages.
Check a file before you argue about it
Our EN 16931 validator is free, needs no account and stores nothing. Paste a UBL invoice and it tells you which business rule fails and why — 44 checks, Peppol BIS 3.0 and national customisations included. It is as useful for a file somebody sent you as for one you produced.
Numbering, which surprises people
In some countries the invoice number is yours. In others the authority allocates it, and the document is not final until it comes back. Oltrano follows the rule for the country rather than pretending they are the same, and the country page says which one you are in.
Corrections
If the original went to an authority, the correction goes too, referencing it. You issue a credit note the usual way; the reporting happens behind it.
Questions people actually ask
Is a PDF invoice an e-invoice?
No, not under EN 16931. A PDF is a picture of an invoice. An e-invoice is structured data a machine can validate and post without a human reading it.
What is BR-CO-17?
An EN 16931 business rule: for each VAT category, the VAT amount must equal the taxable base multiplied by the rate, rounded to two decimals. It is the most commonly failed rule, usually caused by rounding line by line instead of per category.
Do I need Peppol if my country has its own system?
Usually not for domestic invoices — the national system takes those. Peppol is how you reach buyers abroad, and some public buyers require it specifically.
Next
- VAT, reverse charge and VIES checksWhen tax comes off automatically, and when it must not.
- How to correct an invoice you already sentCredit note, void, or neither — and how to tell which one you need.