Austrian VAT number check
Check an Austrian supplier's or customer's number against VIES, the European Commission's register. Below: the format, what it's called locally, and the mistakes that make a correct number fail.
Paste the number with or without the country prefix. Nothing you enter is stored.
The format
| Prefix | AT |
|---|---|
| After the prefix | U + 8 digits |
| Structure | One block of 9 characters. The first character after AT is always the letter U. |
| Example | ATU12345678 |
You can paste the number with spaces, dots or dashes; the checker removes them.
What it's called
Umsatzsteuer-Identifikationsnummer, usually shortened to UID or UID-Nummer.
The UID is separate from the Steuernummer (tax number). The tax office normally assigns it with the Steuernummer when a business registers; otherwise the business applies on form U15. A business has one UID, even with several branches.
Registered, but invalid in VIES?
Small businesses under the Kleinunternehmer exemption get a UID only when they ask for one, usually because they deal with businesses in other EU countries.
What trips people up
- The U is part of the number. ATU12345678 is right; AT12345678 will come back invalid.
- Numbers starting with EU, IM or IN, or ending in -EX, are OSS, IOSS or small-business scheme identifiers, not UIDs.
Other ways to check
UID-Bestätigungsverfahren in FinanzOnline: Needs a FinanzOnline login. Austrian businesses use it to confirm their EU partners' numbers and keep the confirmation. For cross-border trade, the VIES result above is the one to keep with your VAT records.
Sources
Formats from the European Commission's VIES FAQ, checked 16 October 2026. Rules can change; the tax authority's own guidance wins.
Questions about Austrian VAT numbers
What is the format of an Austrian VAT number?
AT followed by U + 8 digits. One block of 9 characters. The first character after AT is always the letter U. Example: ATU12345678.
What is an Austrian VAT number called?
Umsatzsteuer-Identifikationsnummer, usually shortened to UID or UID-Nummer. The UID is separate from the Steuernummer (tax number). The tax office normally assigns it with the Steuernummer when a business registers; otherwise the business applies on form U15. A business has one UID, even with several branches.
Why would a correct Austrian VAT number show as invalid in VIES?
Small businesses under the Kleinunternehmer exemption get a UID only when they ask for one, usually because they deal with businesses in other EU countries.