Invoice Fields Checker
Before the invoice goes out — or before it becomes an e-invoice and gets rejected by a machine. Paste the fields and see which mandatory particulars are missing, and whether the three numbers at the bottom actually agree.
🔒 Your invoice never leaves your browser.
Why a paper invoice is worth checking against e-invoicing rules
The arithmetic findings here carry EN 16931 rule numbers — the same
BR-CO-15 and BR-CO-17 that a Peppol access point will quote when it
rejects your invoice later. An invoice whose VAT does not equal taxable amount times rate is
already broken; the only difference after the e-invoicing mandate is that a machine says so
instead of an accountant.
The scenario decides which particulars are mandatory
A customer VAT number is required when the customer accounts for the tax on an intra-EU supply, and is merely useful otherwise. This tool works the scenario out from the two VAT number prefixes — and when it cannot, it says scenario not determined rather than assuming one. Guessing here would either invent a requirement or hide one.
Zero VAT always needs a reason
A zero amount with nothing beside it is the most common reason an intra-EU invoice comes back with a question. The invoice has to say on what basis no VAT is charged — the exemption provision, or the words reverse charge.
What this tool does not do
It does not check national add-ons: several member states require particulars beyond the directive, and we would rather cover none of them than half. It does not verify a VAT number is registered (that is VIES, and it needs a network call). And it is not tax advice.
Every check this tool runs (16 rules, plus EN 16931 arithmetic)
INV-001 No invoice number
An invoice carries a sequential number that identifies it uniquely. It is the first thing a tax authority looks for and the thing every later correction refers back to.
Fix: Add the number from your own unbroken sequence.
INV-002 No issue date
The date of issue is a mandatory particular in its own right, separate from the date of supply. Where they differ, both are required.
INV-003 No supplier VAT identification number
The VAT identification number under which the supplier made the supply must appear on the invoice. Without it the customer cannot deduct the VAT, which turns a formatting problem into a cash problem for someone else.
INV-004 No customer VAT number on an intra-EU B2B supply
When the customer is liable for the tax on an intra-Community supply, their VAT identification number is mandatory — it is the evidence that the reverse charge applies at all.
Fix: Obtain and show the customer VAT number, and verify it in VIES before invoicing.
INV-005 No supplier name and address
The full name and address of the supplier are mandatory particulars.
INV-006 No customer name and address
The full name and address of the customer are mandatory particulars.
INV-007 No description of the goods or services
The quantity and nature of the goods, or the extent and nature of the services, have to be stated. "Services rendered" is the classic line that fails an audit.
INV-008 No date of supply
The date on which the supply was made or completed is required where it differs from the issue date. Invoices issued in a later period than the supply are exactly the case where it matters.
INV-009 No taxable amount
The taxable amount per rate, the unit price excluding VAT and any discounts not included in it are mandatory. A gross total alone does not satisfy this.
INV-010 No VAT rate
The VAT rate applied must be stated, per rate where several apply.
INV-011 No VAT amount
The VAT amount payable must be shown, except where a special scheme excludes it. It is the number the customer deducts, so an invoice without it is not deductible.
INV-012 Zero-rated or exempt without stating why
When VAT is not charged, the invoice must say on what basis — a reference to the applicable provision, or wording such as "Reverse charge". A zero amount with nothing beside it is the most common reason an intra-EU invoice is queried.
Fix: Add the exemption reference, or the words "Reverse charge" where the customer accounts for the tax.
INV-013 VAT charged to a customer in another EU member state
On a B2B supply to a VAT-registered customer in another member state the tax is normally accounted for by the customer, and the invoice carries no VAT. Charging it here is either a mistake or a case where a special rule applies — and the invoice does not say which.
Fix: Either apply the reverse charge and state it, or state the rule that makes this supply taxable where you are.
Source: yaktool engineering reading, not a quotation: the particulars listed here follow Article 226 of the EU VAT Directive (2006/112/EC) as commonly transcribed; national law adds further requirements this tool does not cover. Confirm against your own tax advice.
INV-014 Currency missing
Amounts without a currency are not amounts. EN 16931 makes the invoice currency a mandatory business term for exactly this reason.
INV-015 Supplier or customer VAT number is not well formed
The number does not match the length and character pattern its country prefix implies. A well-formed number can still be unregistered, but a malformed one is certainly wrong — and this check costs nothing.
Fix: Correct the number, then verify it in VIES before the invoice goes out.
Source: yaktool engineering reading, not a quotation: the particulars listed here follow Article 226 of the EU VAT Directive (2006/112/EC) as commonly transcribed; national law adds further requirements this tool does not cover. Confirm against your own tax advice.
INV-016 VAT number fails its country check digit
The format is right but the check digit built into the number does not agree with the rest of it — several member states (Germany, the Netherlands, Italy and others) build one in. This is a stronger signal than a format mismatch: the number was almost certainly mistyped rather than merely formatted oddly.
Fix: Re-key the number from the customer's own documentation, then verify it in VIES.
Source: yaktool engineering reading, not a quotation: the particulars listed here follow Article 226 of the EU VAT Directive (2006/112/EC) as commonly transcribed; national law adds further requirements this tool does not cover. Confirm against your own tax advice.
Arithmetic findings use the official Peppol / EN 16931 rule identifiers, quoted verbatim from the published rule set. EUR-Lex blocks automated requests, so its entry in our source registry is marked for manual re-verification rather than claimed as machine-checked.