Austria VAT number: format and validation

By Remco from Avatcado

Format

AT followed by the letter U and 8 digits. The local term is Umsatzsteuer-Identifikationsnummer (UID, German).

Pattern: /^U\d{8}$/

  • Always begins with U after the AT prefix; there is no all-digit Austrian VAT number
  • The UID is separate from the domestic Steuernummer; small businesses under the Kleinunternehmer exemption often have no UID until they request one for intra-EU trade

Example of a registered number: ATU14189108

Check digit

Austria VAT numbers carry a check digit (Weighted MOD 10): The last digit is derived from the first seven using alternating weights with digit sums and the formula (96 - sum) mod 10.

Check a Austria VAT number

Checks route through VIES. Caching is enabled by default. Read the source, original result time and freshness label alongside validity; a cached or stale result does not freshly confirm current registration.

Enter a VAT number to see its registration result, source and freshness

Validate via API

The same validation as an API call, with the example number above:

curl "https://api.avatcado.com/v1/validate?vat_number=ATU14189108" \
  -H "Authorization: Bearer avat_live_your_api_key"
import Avatcado from "@avatcado/node";

const avatcado = new Avatcado("avat_live_your_api_key");
const { data, error } = await avatcado.vat.validate({
  vatNumber: "ATU14189108",
});

if (data?.data.valid) {
  console.log(`Registered: ${data.data.company?.name}`);
}

Free tier includes 500 validations per month. Get an API key or read the API documentation.

How Avatcado validates Austria numbers

  • Primary source: VIES.
  • Company name and address: yes, observed 2026-09-04.
  • When VIES is down: the most recent cached result, then a refunded 503.

See the full coverage table.

Frequently asked questions

What is the VAT registration threshold in Austria?

Since 1 January 2025 the Kleinunternehmer exemption covers annual turnover up to EUR 55,000 gross (previously EUR 35,000 net). A single overshoot of up to 10 percent keeps the exemption until year end.

How do I look up an Austrian UID?

There is no public national register. Austrian businesses confirm a partner's UID via FinanzOnline (stage 1 and 2 confirmation); everyone else uses the EU VIES tool or a validation API.

How does Avatcado validate Austria VAT numbers when VIES is down?

For Austria VAT numbers, uncached checks use VIES, the EU's VAT Information Exchange System, which routes the query to Austria's own national database. Caching is enabled by default without a requester VAT number. Read the freshness label and original result time to distinguish a new lookup from a previous result. A valid answer includes the registered company name and address that Austria's tax administration publishes through VIES, which we last confirmed against a real registered number on 2026-09-04. No national register is published for Austria that Avatcado can consult as a substitute, unlike the ten EU countries with a national fallback on Pro and Business, so an availability fault such as MS_UNAVAILABLE or a timeout can be answered only by eligible cache. A stored result has meta.cached: true and meta.source_status: "unavailable", plus meta.stale: true when it is past the cache window. Requester checks disable stored responses by default; cache=true opts back in. If no eligible stored result can answer, the request returns a refunded 503 (upstream_member_state_unavailable). A cached or stale result is earlier registration evidence, not a fresh check.

Related guides

VAT rate in Austria

The standard VAT rate in Austria is 20%. Reduced rates: 13%, 10%, 4.9%. See all Austria VAT rates.

Sources