When a B2B Customer Won't Give You a Valid VAT Number

Short answer: none of the three outcomes stops you from invoicing. No number and a confirmed-invalid number both mean the cross-border exemption or reverse-charge treatment isn’t available right now, so you charge VAT as you would to any customer without one – the exact rate and place of supply depend on whether you’re selling goods or services. An unavailable check is different again: it’s not a negative result, so retry it, record the attempt, and either hold the invoice or charge VAT and correct it once the number is confirmed.

This post covers B2B customers established in another EU member state. A customer in your own country is a domestic sale either way – neither the cross-border exemption nor the standard reverse-charge rules apply to it, though some countries run their own domestic reverse-charge regimes for specific sectors. Check that separately if it’s relevant to you.

Three situations, and they’re not the same problem

No VAT number given at all

Some customers genuinely don’t have one – they’re below their own country’s VAT registration threshold, or they’re a sole trader who hasn’t registered. Others just haven’t filled in the field yet. Either way, you have nothing to verify, so there’s nothing to zero-rate against.

A number was given, but it doesn’t check out

The string exists, but it fails when you run a VAT check against it. Several things can produce ‘invalid’: the number was never registered, the business hasn’t completed the separate intra-EU registration some member states require, or the registration lapsed. One of the more common causes is a number that’s valid domestically but not activated for intra-EU transactions – VIES reports it as invalid even though the business is VAT-registered at home. VIES invalid for a domestic-only registration covers how that cause plays out and what to tell the customer. And don’t confuse ‘invalid’ with ‘badly formatted’ – a string that merely fails the pattern check is a different, earlier problem; see format-valid vs. actually registered for that distinction.

VIES or a member-state service can’t confirm it right now

This one gets mistaken for invalid constantly. An unavailable check means the lookup didn’t complete – not that the number failed. Retry it, and keep a record of the attempt and its timestamp regardless of outcome. Handling VIES downtime and the error reference show what the response looks like in that case, so you can tell it apart from a genuine negative in code rather than by eyeballing a dashboard.

What EU rules actually let you assume

There’s no general EU obligation to collect a VAT number from every B2B customer. The rules describe what you can rely on once you do have one – or once you’ve established you don’t.

For services, Implementing Regulation 282/2011 Article 18 sets out two routes. Under Article 18(1)(a), unless you have information suggesting otherwise, you may treat an EU customer as a taxable person once they’ve given you a VAT ID and you’ve obtained confirmation – per Article 31 of Regulation (EU) No 904/2010 – of both its validity and the associated name and address. Under Article 18(1)(b), a customer who says they’ve applied for a number but doesn’t have one yet can still be treated as a taxable person if you have other proof of that and you’ve done reasonable verification. And under Article 18(2), unless you have information to the contrary, you may treat a customer as non-taxable once you can show they haven’t given you a VAT ID at all. Note the word ‘may’ throughout – this is a permission and a presumption you’re allowed to rely on, not a mandatory checklist with one correct outcome.

For goods, the relevant condition sits in Directive 2006/112/EC Article 138(1), as amended by Directive (EU) 2018/1910 from 1 January 2020: the exemption requires the customer to be identified for VAT in another member state and to have given you that VAT ID, plus a correct recapitulative statement under Article 138(1a). It’s one condition among several – transport evidence is the other half – but if no qualifying number is indicated to you (or only a number from the dispatch country), the exemption doesn’t apply and you must charge VAT.

What to charge instead

Goods. No valid VAT ID means the Article 138 exemption isn’t available, but that doesn’t automatically make it a domestic-rate sale. If the customer is a genuine taxable person who just didn’t share a number, VAT is normally due in the country where transport begins, at your own rate. If the customer is actually non-taxable for VAT purposes – a non-taxable legal person, or a business below its own country’s acquisition threshold under Article 3(1) – you’re making an intra-Community distance sale under Articles 14(4) and 33(a): VAT is due where the goods end up once you’re over the same combined €10,000 Article 59c threshold described below, usually accounted through the One Stop Shop.

Services. Don’t flatten this to ‘charge your own rate.’ The general rule (Article 45) puts the place of supply where you’re established, so for most B2B services without a valid customer VAT ID, you’d apply your own country’s VAT. But most SaaS falls under the specific rule for telecom, broadcasting, and electronically supplied services (Article 58), which puts the place of supply where the customer is, once you’re over the combined EU-wide €10,000 threshold in Article 59c for suppliers established in only one member state. That threshold counts these cross-border service sales together with any intra-EU distance sales of goods you also make. Below that threshold you can still apply your own domestic VAT; above it, VAT for other member states is usually accounted through the One Stop Shop rather than registering separately in each one. A handful of other services have their own place-of-supply rules too. If you’re not sure which rule a service falls under, confirm it before you decide what to charge: the wrong assumption here is a recurring source of mispriced invoices, not just a paperwork gap. When reverse charge applies and how it’s invoiced is covered in the reverse-charge concept guide and by-country invoice wording.

In both cases this isn’t a one-off decision per customer. Know when to re-check a customer’s VAT number, so a number that starts invalid or missing doesn’t stay that way in your records after it’s been fixed.

What to tell the customer

No number at all. Tell them plainly that without a VAT ID you’ll charge VAT as you would for any customer without one, and that you’ll switch the treatment as soon as they provide a number that checks out. If they’re a sole trader, their VAT number can be built from a personal national identifier in some member states – reluctance to hand it over in a support chat might be a privacy concern, not an attempt to dodge tax. The same applies on your side: a sole trader’s VAT number, name and address are personal data, so keep them in your billing records where you need them, not in support transcripts, debug logs or analytics.

Invalid number. Say exactly what failed – the number didn’t come back confirmed – and ask them to double-check it with whoever handles their VAT registration, since a typo and an unregistered number look identical from your side. Don’t promise to retroactively fix the invoice until you actually have a number that checks out.

Check unavailable. Tell them the check didn’t complete, not that their number is wrong – that distinction matters to the finance team reading your email. Let them know you’ll retry, and that the failed lookup says nothing yet about their registration.

If it later turns out VAT shouldn’t have been charged, the usual fix runs through you, not the customer’s tax authority: you correct the invoice and refund the VAT, then adjust your own return under your national rules. The cross-border refund procedure under Directive 2008/9/EC covers VAT that was correctly charged and is deductible, not VAT invoiced in error. If a customer pushes back, tell them how you correct invoices, and don’t promise a refund outcome on their side.

What to record

Keep the same three things for every outcome: what you asked for, what came back, and when. A definitive invalid result, a definitive ‘no number given,’ and a transient unavailable result all look different in an audit, and conflating them later is how a routine outage turns into a disputed invoice years on. What auditors look for in EU VAT documentation covers the fuller checklist; if you’re set up to run requester-qualified checks, the consultation number VIES issues on those is the strongest form of that evidence – see the VIES consultation number for finance teams.

vatnode’s GET /v1/vat/:vatId on this EU VAT validation API returns valid as true or false along with source, a timestamp, and a check ID on every answered check. An outage is never reported as a silent ‘invalid’: either a national source answers instead, and source says so, or the call comes back as an error such as VIES_UNAVAILABLE. A national-source answer isn’t the same as a VIES confirmation, though. It reflects that country’s own register, which may not show whether the number is activated for intra-EU transactions, so check source before relying on a valid: true for the exemption or the reverse charge. The three outcomes above are distinguishable in the response itself, not just on a dashboard. The consultation number is included once your account has an EU VAT number set in dashboard Account details and VIES answers live.

If the number arrives later

If a customer sends a valid number after you’ve already invoiced them without one, there’s no EU-wide deadline or procedure forcing a fix within a set window. Article 219 treats a document that amends and clearly references the original invoice – a credit note plus a corrected one – as an invoice in its own right, so that’s the usual mechanism. Whether you do it, and how, is a matter of national law and your own process. A number arriving later doesn’t by itself mean the original invoice was wrong. If you applied Article 18(2) correctly, or charged VAT on the information you had and had no information to the contrary, you were relying on a presumption the rules expressly allow. Zero-rating on a number that later turns out to have been invalid is a different, higher-stakes problem – covered in what happens when you reverse-charge an invalid VAT number.

FAQ

A customer has no VAT number at all – what do I charge?

For services, Implementing Regulation 282/2011 Article 18(2) lets you treat them as a non-taxable person when you can show they haven’t communicated a VAT ID, and charge accordingly. For most SaaS that means the place-of-supply rule for electronically supplied services: your own country’s VAT below the EU-wide €10,000 threshold for suppliers established in one member state, the customer’s country’s VAT above it. For goods, the Article 138 exemption needs a VAT ID the customer gave you; without one, it doesn’t apply. VAT is then normally due where transport begins if the customer is a genuine taxable person who just withheld the number. If they’re non-taxable or below their own acquisition threshold, it’s an intra-Community distance sale, taxed at destination above the combined €10,000 threshold. This is general information, not tax advice for a specific transaction.

The customer gave a number but VIES says it’s invalid – can I still zero-rate?

No, not on this number. The goods exemption (Article 138), and the Article 18 customer-status presumption that lets you apply reverse charge under Article 196 instead of your own VAT, both depend on a VAT ID that actually checks out. For services the treatment is reverse charge rather than a zero-rated line, because the place of supply moves to the customer’s country. An invalid result means that condition isn’t met at this time, regardless of why – unregistered, not yet activated for intra-EU transactions, or simply wrong. Ask for a correction or fall back to charging VAT; don’t treat an invalid number as a formality to wave through. This is general information, not tax advice for a specific transaction.

VIES is down and won’t confirm the number – is that the same as invalid?

No. An unavailable check is a different outcome from invalid. The number may be perfectly valid; the lookup just didn’t complete. Retry, and keep a record of when you tried and what came back. Until the number is confirmed you can’t rely on it for the exemption or the reverse charge, so either hold the invoice until a retry succeeds – within the Article 222 deadline for exempt and reverse-charge supplies, the 15th of the month after the chargeable event – or charge VAT now and correct it once the number is confirmed. If you’ve already been paid for services, Article 65 can make VAT chargeable on receipt, so holding the document alone may not move the tax point. Don’t record the outage as an invalid result.

Do I have to ask every customer for a VAT number before I can invoice them?

No EU-wide rule requires it. Asking is how you access the exemption or the reverse-charge treatment where it applies; a customer who doesn’t have or won’t give a number is simply treated under the rules for a customer without one. Not providing one doesn’t stop you invoicing them.

If a valid number arrives after I’ve already invoiced without one, do I have to redo the invoice?

There’s no EU-wide procedure or deadline for this. A document that amends and clearly references the original invoice is itself treated as an invoice under Article 219, so a credit note plus a corrected one is the usual route – but whether and how to reissue is a matter of national law and your own process, not a single EU rule.