VIES Says “Invalid VAT Number” — How to Fix It When the Business Is Real

You are about to invoice an EU customer without VAT, VIES returns invalid, and the customer insists they are registered. Both can be true. Here is why, and the order to troubleshoot it.

What this error actually means

VIES (the VAT Information Exchange System, run by the European Commission) is not a database of its own. It is a search engine: your query is forwarded in real time to the national VAT database of the member state you selected. An invalid result means one specific thing: on the day you asked, that country's database did not have this number recorded as identified for intra-EU transactions.

That is narrower than it sounds: VIES does not check whether a company exists, is in good standing, or even holds a domestic VAT registration. Three different situations produce the same invalid response:

• The number genuinely does not exist — usually a typo or formatting slip.
• The number exists, but only as a domestic VAT registration never activated for cross-border (intra-EU) transactions.
• The registration is real but too recent, and not yet finalized in the national database.

The second case is the most common for a real, trading business — but rule out the cheap explanations first.

Step 1: rule out a formatting problem

Every member state issues VAT numbers in a fixed pattern — set length, sometimes letters in defined positions (Austrian numbers begin with U, for example). Before questioning the registry, make sure the string itself is well-formed:

1. Strip spaces, dots, and dashes, and retype rather than paste — invisible characters copied from PDFs and emails are a classic culprit.
2. Do not repeat the country prefix. The VIES form already sets the member state from a dropdown; typing the two-letter code again is a frequent cause of false failures.
3. Make sure it is actually the VAT number. Companies hold several identifiers — company register numbers, domestic tax references — that look similar but are not the VAT ID.

Our free VAT number validator checks the structure in your browser: country pattern, length, allowed characters, and the national checksum where one exists. To be clear, our tool validates format only — a number can be perfectly formed and still be unregistered, because only VIES queries the actual national registries. (Why a checksum can pass while a registry says no is explained in how check digits work.)

If the format check fails, fix the string and retry VIES — that resolves a surprising share of these errors. If it passes, keep going.

Step 2: make sure the number can be in VIES at all

Since 1 January 2021 the United Kingdom is no longer part of VIES, so a GB-prefixed number will never validate there — use HMRC's “Check a UK VAT number” service on GOV.UK instead. The exception is Northern Ireland: XI-prefixed numbers remain in VIES under the post-Brexit arrangements, but only for transactions in goods, not services.

Step 3: rule out downtime before blaming the number

VIES depends on the national databases of all 27 member states (plus Northern Ireland's XI register), any of which can be offline for maintenance. When the national application does not reply, VIES returns a service error — in the web service, the MS_UNAVAILABLE fault, meaning that member state's application is not responding — rather than a verdict on your number. For unavailability messages, the Commission's own advice boils down to patience: retry after a few minutes, or come back later in the day.

The distinction matters: unavailable means the question could not be asked; invalid means it was asked and the answer was no. In bulk validation, treat unavailability as “unknown, retry later” — never record it as invalid.

Step 4: the most common real cause — registered, but not for intra-EU trade

If the format is right, the country is in VIES, and the service is up, you are looking at the classic case: a genuine domestic VAT registration that has never been activated for intra-EU transactions. Some member states require an additional registration for cross-border trade and expose only those numbers to VIES. A business selling only at home may never need it — until its first cross-border order.

The fix sits entirely with the number's owner:

1. The owner contacts their own national tax administration — not the Commission, not the customer's tax office — and requests identification for intra-EU transactions; in some countries this is a separate register of intra-EU operators.
2. Once the administration grants it, the number becomes visible to VIES. How long that takes varies by country — the national office can say.
3. For brand-new registrations, allow processing time: a number issued days ago may not appear until the registration is finalized.

And note: only national tax administrations can update the underlying data — the Commission cannot add, correct, or activate a number.

Why sellers need this check for zero-rated invoicing

Since the EU “quick fixes” took effect on 1 January 2020, zero-rating an intra-EU supply of goods under Article 138 of the VAT Directive requires, as a substantive condition, that your customer holds a valid VAT identification number in another member state and has given it to you — and that you report the supply correctly on your recapitulative statement. A missing number used to be a formality; now it can cost you the exemption.

Practical consequences when VIES says invalid:

• The cautious course is to invoice with VAT until the customer's number validates, then correct afterwards on your tax adviser's guidance.
• Keep dated evidence of every check. Entering your own VAT number in the requester field makes VIES return a consultation number — save it as proof you verified the customer on that date.

If the payment side of the same deal is also misbehaving, see our guide to IBAN errors that block bank transfers.

What to send if nothing works

If you own the number, contact your national tax administration with: the exact number as issued, a reference to your VAT registration certificate, a dated screenshot of the VIES response, and an explicit request to activate the number for intra-EU transactions.

If you are the seller, send your customer: the exact string you entered, the member state selected, the date and time of each attempt, a screenshot, and any consultation numbers from earlier checks. Ask them to confirm with their tax office whether the number is activated for intra-EU transactions — that one question usually unblocks everything.

What won't work

• Re-checking every hour. Retrying is only useful after an unavailability error; a true invalid will not flip until the national administration changes the record.
• Treating a format pass as proof. A structurally valid number is not a registered one — registry status lives with the member state.
• Writing to the European Commission. It cannot amend national VAT data.
• Zero-rating on a promise. “The activation is in progress” is not a valid VAT number at the time of supply. Wait, or invoice with VAT and correct later.

FAQ

Why does VIES say my VAT number is invalid when my company is VAT-registered?

Because VIES checks something narrower than general VAT registration: whether the number is recorded in the national database as identified for intra-EU transactions. In several member states that is a separate status from domestic registration, so a real business can show as invalid until its own tax administration activates the number.

Can I still zero-rate an invoice if VIES shows my customer's VAT number as invalid?

Since the 2020 “quick fixes”, a customer's valid VAT number and a correct recapitulative statement are substantive conditions for the Article 138 exemption on intra-EU supplies of goods. If the number does not validate, the cautious approach is to charge VAT until it does, keep dated evidence of every check, and confirm specifics with your tax adviser.

Why can't I find a UK (GB) VAT number in VIES?

Since 1 January 2021 the UK is no longer part of VIES, so GB-prefixed numbers always come back not found. Use HMRC's “Check a UK VAT number” service on GOV.UK instead. XI-prefixed Northern Ireland numbers remain checkable in VIES, but only for transactions in goods.

What does MS_UNAVAILABLE mean in VIES?

It means the member state's application is not replying or not available, so VIES could not query the national database at all. It is a temporary service error, not a statement about the number: retry later and treat the result as unknown rather than invalid.

This guide is general information, not tax or legal advice. VAT registry status is determined solely by national tax administrations; our validator checks format, not registration. VIES, HMRC, and the European Commission are referenced descriptively, with no affiliation. Confirm the VAT treatment of any transaction with your tax adviser.