What Auditors Look For in EU VAT Documentation

On a sampled zero-rated or reverse-charged intra-EU B2B invoice, an auditor is essentially testing one thing: were the conditions for not charging VAT actually met, and can you show it. Everything below is what ‘show it’ means in practice.

The VAT ID check itself

For a goods supply, Directive 2006/112/EC Article 138(1), as amended from 1 January 2020, makes two things substantive conditions for the exemption: the customer must be VAT-identified in another member state, and the customer must have given you that VAT ID. The article doesn’t mention VIES – it’s about identification and disclosure, not about which system confirmed it.

VIES is how you discharge that condition in practice, and for services the Implementing Regulation points straight at the verification mechanism behind it. Implementing Regulation 282/2011 Article 18 lets you treat an EU customer as a taxable person once they’ve given you a VAT ID and you’ve confirmed it’s valid, unless you have information suggesting otherwise. Either way, an auditor wants to see that the check happened and when.

A plain valid/invalid answer proves you asked. A requester-qualified check – where you supply your own VAT ID alongside the customer’s – goes further: VIES issues a reference number tying a specific check to a specific date and reply. That’s the VIES consultation number, which has its own article.

What the invoice has to say

Directive Article 226 sets the baseline content for every invoice: a sequential number and a date of issue, regardless of treatment. The rest depends on what you’re invoicing:

• 226(4) – the customer’s VAT ID, where the customer is liable for the tax or you’re applying the Article 138 goods exemption.
• 226(11) – for the goods exemption, a reference to the article or other indication the supply is exempt.
• 226(11a) – where the customer is liable under reverse charge, the mention ‘Reverse charge’.

The last two mentions aren’t interchangeable. A goods invoice carries an exemption reference; a reverse-charged services invoice carries the words ‘Reverse charge’. Put the wrong one on the wrong invoice and the content requirement for that specific supply isn’t met. In practice, a sampled review works invoice by invoice: the auditor checks that the mention on the paper matches the treatment the supply actually qualifies for, not the other way round.

Proof the goods left the country

For goods, the invoice content is only half the story – an auditor separately wants evidence the goods were actually transported to another member state. Implementing Regulation 282/2011 Article 45a gives you a rebuttable presumption to work from, built on documents from parties independent of both you and your customer: two non-contradictory items from the first category (a CMR note, a bill of lading, an air freight invoice, a carrier’s invoice), or one from that category plus one from a second (an insurance policy or bank proof of payment for the transport, an official confirmation of arrival, or a destination warehouse-keeper’s receipt).

If the customer arranges transport themselves, the presumption additionally requires a written statement from them naming the destination member state, furnished by the 10th day of the month following the supply. Tax authorities can rebut the presumption even when you hold these documents, and the presumption isn’t the only way to prove transport – it’s a structured shortcut.

Proof the customer is a business

For services, the equivalent evidence is different: you’re not proving transport, you’re proving the customer qualifies as a taxable person. That’s the Article 18 check from the first section – a VAT ID plus a VIES confirmation, as long as you have no information to the contrary. There’s no transport documentation to assemble for a service supply, because nothing physically crosses a border. The ‘information to the contrary’ clause is the practical catch: a valid VIES result doesn’t override something you separately know or learn about the customer, so the check is a floor, not a substitute for using what you already have on file about them.

Recapitulative statement, in sync

Articles 262 and 264 require your recapitulative statement to list the VAT IDs of your intra-EU customers, and those entries should match what’s on your invoices. Article 138(1a) raises the stakes on this: the goods exemption doesn’t apply if you’ve failed to file the statement, or it doesn’t correctly reflect what’s required – unless you can duly justify the gap to the tax authority. An auditor can cross-check the statement against the invoice trail, so the two need to agree.

How long to keep it

Article 247(1) leaves invoice storage periods to each member state – there’s no single EU-wide number, and this isn’t the place to guess one for your jurisdiction. What matters operationally: validation records, transport evidence and the recapitulative-statement entries should all be retained on the same footing as the invoice they support, for as long as that invoice stays open to review. Some of that evidence – a carrier’s invoice, a bank record – isn’t yours to begin with, so the retention question isn’t only how long you keep your own files, but whether you’ve captured a copy of the third-party documents before they age out of someone else’s system.

Linking the check to the invoice

The gap that actually trips teams up isn’t missing evidence – it’s evidence that exists somewhere but isn’t connected to the invoice it’s supposed to defend. A VIES check logged in one system, a transport document filed in another, and an invoice in a third don’t add up to a trail unless something ties them together.

vatnode’s GET /v1/vat/:vatId response returns valid, verifiedAt, source (VIES, CACHE, or a national registry code when VIES was unreachable), and consultationNumber – non-null only when your account has an EU VAT number set in Account details and VIES answered live; it’s null on cached and fallback answers. vatnode keeps a history of your checks under the retention set out in its Privacy Policy, but it isn’t your system of record and doesn’t keep that history on your schedule – so persist these fields against the invoice in your own records, append-only, the moment the check runs. A checkId is useful as a cross-reference to vatnode’s copy, not as the only copy of the evidence. If a check involves a sole trader’s VAT number, keep in mind it can embed a personal ID number in some member states – treat it as personal data and keep it in the one field rather than splitting it apart.

This is general information about EU VAT documentation, not tax or legal advice – whether your specific evidence satisfies a given audit is a question for your adviser.

FAQ

What does a VAT auditor actually ask to see on a cross-border B2B invoice?

Typically three things: that the customer’s VAT ID was valid at the time of supply, that the invoice itself carries the required content for the treatment you applied, and – for goods – evidence the goods actually left the country.

Do I need to keep proof the goods left the country, or is the invoice enough?

The invoice alone is not enough for a goods supply. Implementing Regulation 282/2011 Article 45a sets out a rebuttable presumption of transport based on independent third-party documents, separate from what’s printed on the invoice.

How long do I need to keep VAT validation records?

Generally on the same footing as the invoice they support. Directive 2006/112/EC Article 247(1) leaves the exact period to each member state, so there’s no single EU-wide number – check with your adviser for your jurisdiction.

What if I validated the VAT number but it later turns out to be invalid?

Your check shows what was true when you ran it. A later deregistration doesn’t rewrite that record, but it’s worth understanding what happens if a number turns out invalid before you issued the invoice.

See what happens if that VAT number turns out invalid for the detail.

Is a VIES consultation number required, or just good practice?

No article in the VAT Directive or its Implementing Regulation requires it. The European Commission’s own guidance recommends keeping it as proof you ran the check, so it’s good practice rather than a legal requirement. The full picture – including when to re-check a customer’s VAT number and how to build the VIES consultation number and VAT audit trail end to end – is worth reading before you design your own process. The VIES API runs the requester-qualified check and returns the consultation number as a structured field once your EU VAT number is set in Account details.