Three things come up again and again when a business starts sending invoices across a border, and all three are yes-or-no questions that should not require signing up for anything. Is this XML file actually a valid e-invoice, or will the customer's system reject it? Is this VAT identification number real and current, so that the reverse-charge line on my invoice is defensible? What is my counterparty's Peppol address, and what is mine? Each has a tool below. None asks for an account, an e-mail address or a card, and none keeps the file you upload.
Check an e-invoice before someone else rejects it
The e-invoice checker takes an XRechnung, a ZUGFeRD or Factur-X PDF, a UBL or CII file, or a Polish FA(3), and validates it against the EN 16931 semantic model and the national rule set that applies to it. What comes back is not a verdict but a list: which business rule failed, what the rule says, and where in the document it failed. That matters because "invalid" from a customer's portal is usually all you are told, and the difference between a missing buyer reference and a wrong tax category is the difference between a two-minute fix and a rebuilt document. The file is validated and discarded; nothing is stored and no account is created.
Check a VAT identification number
A reverse-charge invoice to a business in another EU member state rests on the customer's VAT identification number being valid on the day you invoice. The VAT ID check queries the European Commission's VIES service and tells you what VIES says — valid or not, and the name and address where the member state chooses to return them. Two honest caveats belong with it: VIES answers for the member state's own register and is sometimes unavailable, and a check today is not evidence about a supply last quarter. Keep the confirmation with the invoice; that is what the record is for.
Build a Peppol participant identifier
Peppol addresses are not e-mail addresses. A participant identifier is a scheme and a value — a Belgian company number, a Dutch KVK number, a German Leitweg-ID, a VAT number where the country allows it — written in a fixed form. The Peppol identifier tool assembles one correctly for the country and scheme you pick, so that the identifier you give a customer, or put in a supplier record, is the one their access point expects rather than one that silently fails to route.
Why these are free
Because they are cheap for us to run and genuinely useful on their own, and because a business that can check a file before sending it has fewer rejected invoices whether or not it ever becomes a customer. There is no gate and no upsell inside the tools. If you want the rest — invoices issued and validated at the moment they get a number, incoming e-invoices read into bills, books, jobs and reports — that is the product, and its prices are on the pricing page.
How KRONENWERK handles this
SUPPORTED The same validation engine that powers the free checker runs inside the product, before an invoice is given a number: a document that would violate EN 16931 or the national CIUS is refused with the rule named, rather than issued and rejected later by the recipient. The VIES check and the Peppol identifier logic are likewise the ones the product uses on customer and supplier records. What the tools do not do: they do not file anything with an authority, do not transmit an invoice, and do not give tax advice. See e-invoicing in Europe for the formats and the timetable.
Frequently asked questions
Do you keep the file I upload?
No. The document is validated and discarded. No account is created and no e-mail address is asked for.
Which formats does the checker accept?
XRechnung, ZUGFeRD and Factur-X (the PDF with the XML inside), plain UBL and CII, and the Polish FA(3). See the formats page.
Is a VIES result proof?
It is what VIES answered at that moment, and it is worth keeping with the invoice. It is not a substitute for your adviser's judgement about the supply, and VIES is occasionally unavailable.
Can I call these from my own software?
The validation and identifier logic are available through the API on the plans that include it; see the e-invoicing API.
Will you add more tools?
Where the same question keeps arriving and the answer can be given honestly without an account, yes.
The pages in this guide
- Free e-invoice checker: validate XRechnung, ZUGFeRD, Factur-X, UBL, FA(3) Upload an e-invoice and check it against a country's rules: schema plus Schematron business rules. No account, nothing stored, files up to 25 MB.
- VAT ID check via VIES: verify an EU VAT number and what the answer means Check an EU VAT identification number against VIES, the Commission's register: what a valid answer means, why it is not reverse charge, and the country formats.
- Peppol identifier tool: build a participant ID and look it up in the Directory Compose a Peppol participant identifier from scheme and value, check it in the Peppol Directory, and read the common ISO 6523 schemes for BE, DE, FR, NL and PL.