What Is a VAT Number? EU VAT IDs Explained
Quick answer: what is a VAT number?
An EU VAT number identifies a business for VAT purposes. It normally starts with a country prefix followed by a country-specific sequence of letters and digits. Businesses use it on invoices and for cross-border VAT processes, but a number should be checked before it is relied on.
Use our VAT number checker to run a VIES-backed validation.
VAT number, VAT ID and UID
Different countries use different names, including VAT identification number, VAT ID, USt-IdNr., UID or numéro de TVA. These terms generally refer to the identifier used for VAT-related business transactions. The exact format, length and prefix depend on the country.
When is a VAT number used?
A VAT number can be relevant when a business issues invoices, buys or sells across borders, registers for VAT or provides its tax details to a supplier. It is not the same as a company registration number, local tax number or bank account number.
Why check a VAT number?
Checking the number can help confirm that it has a recognizable country format and that the official VIES service returns a result. This supports supplier onboarding and invoice workflows. Keep the date and result of important checks in your records.
A positive result does not replace tax advice and may not include every company detail for every country.
See the country VAT checks for country-specific entry points.
What a VAT number is used for
Businesses use VAT numbers to identify themselves on invoices, tax returns, and cross-border transactions. A number can help a supplier determine which customer record is involved and which tax procedure may apply. It is not the same as a company registration number, a personal tax number, or a bank account number. A single business can have several identifiers for different administrative purposes, so the label on a form matters.
For an EU business selling to another EU country, the VAT number is commonly relevant to the treatment of a business-to-business transaction. The exact tax result depends on the goods or services, the countries involved, the customer’s status, and the applicable rules. A VAT checker can help with the identifier, but it cannot decide the tax treatment of an invoice.
VAT number, VAT ID and tax number
The terms used in English-language systems are not always interchangeable. “VAT number” and “VAT ID” usually refer to the identifier used for value added tax registration. “Tax number” may refer to a broader or different identifier issued by the national tax administration. In Germany, for example, the Umsatzsteuer-Identifikationsnummer is distinct from the domestic tax number. In other countries, terminology and the relationship between identifiers differ.
When a customer asks for a VAT number, confirm which identifier the invoice or tax process requires. Do not infer the answer from a company name alone. If the customer provides several numbers, record their labels and country so accounting staff can select the correct one later.
What information can be checked
A basic format check can assess the country prefix, allowed characters, length and, where applicable, check digits. A database or official verification service may provide a stronger result by checking whether the number is recognized as registered. Even then, the result has a scope and a timestamp. It may not prove the current legal name, the exact trading activity, or the customer’s entitlement to every tax treatment.
Treat a validation result as one part of due diligence. For a new supplier, compare the number with the legal name and address shown on authoritative documents. For a high-value transaction, keep a record of the verification date and result. This creates a clearer audit trail than storing only a green “valid” label.
Where to find a VAT number
The number may appear on an official invoice, a tax registration certificate, a company’s legal notice, an online tax account, or a public business document. The location and display format vary. A web page alone should not be treated as proof when payment or tax risk is significant; confirm the value with the business or the relevant authority.
If a number is copied from a PDF or scanned document, check for common transcription mistakes: a missing country prefix, an added space in the wrong place, an O entered instead of zero, or a leading digit omitted. Ask the issuer to resend the value as text when the source is unclear. Normalizing presentation characters is useful, but changing the underlying characters is not.
A sensible validation workflow
Start by selecting the country explicitly. Then normalize only permitted formatting characters, run the local format check, and show a clear error if the value is structurally impossible. If the transaction requires an authoritative status check, use the appropriate national or EU service and record the response. Finally, compare the result with the business identity on the invoice and keep the evidence according to your accounting policy.
This sequence separates three questions: does the value look correctly formed, is it recognized by a verification service, and does it belong to the party involved in the transaction? Keeping those questions separate prevents a format check from being mistaken for a complete tax or identity decision.
Common data-entry mistakes
Do not copy only the digits and omit the country context. Also check older invoices after a legal-name change or a new registration. Keep the original value, the normalized value and the verification date separate so accounting staff can explain how the identifier was used.
Keep country and source together
In an international system, a VAT number should be stored with its issuing country, source and verification date. If two documents contain different values, do not automatically select the newest one. Ask the business to confirm the current identifier and record the decision before issuing the next invoice.
FAQ: EU VAT numbers
Does every EU business have a VAT number?
No. Whether a business needs one depends on its activities, registration status and national rules.
Is a VAT number the same as a company number?
No. A VAT number is used for VAT purposes; a company may have separate registration and tax identifiers.
Can a VAT number be checked online?
Yes. The official VIES service can return a validation result for participating EU VAT numbers.
Summary
An EU VAT number is a country-specific business identifier for VAT processes. Understand the local format and check the number before invoicing or adding a supplier.
Source: European Commission: VIES.