Österreich · UID-Nummer
Austrian UID-Nummer Checker
Check an Austrian Umsatzsteuer-Identifikationsnummer (UID / ATU number) for correct format and confirm in real time, via the EU VIES system, that it is valid — with the registered name and address.
What is an Austrian UID-Nummer?
The UID-Nummer (Umsatzsteuer-Identifikationsnummer, often called the ATU number) is Austria’s VAT identification number: ATU followed by eight digits, such as ATU14189108. The tax office issues it to businesses for invoicing and EU trade; it is separate from the 9-digit Steuernummer and the Firmenbuchnummer.
Austrian UID-Nummer format
AT for Austria, a fixed letter U, seven digits and a check digit.
Example: ATU14189108 (OMV Aktiengesellschaft, as printed in its Impressum).
- 11 characters: Always ATU plus eight digits, written without spaces. The U is part of the number, not optional.
- Check digit: The eighth digit is a check digit. No official algorithm is published, but valid numbers consistently satisfy a Luhn-type mod-10 check with a fixed offset of 4 — the widely copied ATU12345678 fails it.
- Not a UID: A Firmenbuchnummer (FN 93363z) or a 9-digit Steuernummer will not pass — this checker validates UID numbers only.
- Name and address: Austria releases the registered name and address through VIES, so a valid result shows who the number belongs to.
How to check an Austrian UID-Nummer
- 1 Find the UID in the company’s Impressum or on its invoice.
- 2 Enter it above as ATU plus eight digits. The checker validates the format and check digit, then confirms the number live via VIES.
- 3 Compare the returned name and address with the business you are invoicing, and keep the result with your records.
- 4 Want to run the official checks yourself? Our EU VAT verification guide walks through them step by step.
Frequently Asked Questions
How do I check an Austrian VAT number? (Wie prüfe ich eine UID-Nummer?)
Enter it in the checker on this page: it validates the ATU format and check digit, then confirms the number in real time via the EU VIES system and shows the registered name and address. For the official verification routes, see our EU VAT verification guide.
What is the ATU number format?
ATU followed by eight digits — 11 characters in total, for example ATU14189108 (OMV Aktiengesellschaft). The last digit is a check digit. Enter it as one string without spaces; “ATU-Nummer” is simply the common nickname for the UID-Nummer.
What is the difference between UID-Nummer, Steuernummer and Firmenbuchnummer?
The UID-Nummer is the VAT number used on invoices and for EU trade. The 9-digit Steuernummer identifies the tax account with the Finanzamt. The Firmenbuchnummer (for example FN 93363z — up to six digits and a check letter) identifies a company in the commercial register. Only the UID can be checked in VIES.
When must the customer’s UID appear on an invoice?
On domestic B2B invoices over €10,000 including VAT and on reverse-charge invoices. For exempt intra-Community supplies of goods, both the supplier’s and the customer’s UID are required. Invoices up to €400 (gross) need no UID, except for intra-Community supplies and triangular transactions.
Where do I find a company’s UID-Nummer?
In its Impressum: Austrian website operators must publish their UID-Nummer if they have one, together with their Firmenbuchnummer if registered. It also appears on the company’s invoices. A UID cannot be looked up by company name in VIES.
Is ATU12345678 a valid example?
No. It is the placeholder many sites use, but its check digit is wrong, so it fails before any registry lookup. Use a real published number such as OMV’s ATU14189108, or the checksum-valid dummy ATU12345675 for format testing.
Last reviewed: , against official sources.
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Check Austrian and EU VAT numbers against VIES in one API call — with registered name and address where the country provides it.