Slovenia VAT number: format and validation

By Remco from Avatcado

Format

SI followed by 8 digits. The local term is identifikacijska stevilka za DDV (davek na dodano vrednost) (ID za DDV, Slovene).

Pattern: /^\d{8}$/

  • The VAT ID is simply the company's 8-digit davcna stevilka (tax number) with an SI prefix; every taxpayer has a tax number, but only VAT-registered ones may use it with SI
  • The first 7 digits are randomly assigned; the 8th is a control digit

Example of a registered number: SI82646716

Check digit

Slovenia VAT numbers carry a check digit (MOD 11): The 8th digit is a check digit computed modulo 11 over the first 7 digits of the tax number.

Check a Slovenia 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=SI82646716" \
  -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: "SI82646716",
});

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 Slovenia numbers

  • Primary source: VIES.
  • Company name and address: yes, observed 2026-09-04.
  • When VIES is down: FURS (Snapshot refreshed 06:30 and 18:30 UTC) on Pro and Business, then the cached result, then a refunded 503.

See the full coverage table.

Frequently asked questions

Is a Slovenian tax number the same as a VAT number?

Almost: the ID za DDV is the same 8 digits as the davcna stevilka, prefixed with SI. Holding a tax number does not imply VAT registration, so the SI-prefixed form only validates in VIES once FURS has registered the business for DDV.

What is the Slovenian VAT registration threshold?

EUR 60,000 of annual taxable turnover, raised from EUR 50,000 on 1 January 2025. Below it, registration is optional.

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

When VIES cannot answer for Slovenia because of an availability fault such as MS_UNAVAILABLE or a timeout, eligible Pro and Business checks can use FURS, run by Financial Administration of the Republic of Slovenia; the Free plan can use eligible cache instead. FURS publishes its data as a downloadable file rather than a live lookup, so Avatcado reads it from a mirror (Snapshot refreshed 06:30 and 18:30 UTC). That snapshot only answers while it passes two freshness gates: it must itself be less than 3 days old, and the source file behind it must have changed within the last 14 days. A snapshot that fails either gate is retired, and the request falls through exactly as if Slovenia had no register at all. A confirmed answer includes the registered company name and address that FURS publishes. FURS lookups can only confirm a positive: if the register does not carry the number, or cannot confirm it, Avatcado never reports the number invalid on that basis, and the request moves on to the next step instead. A confirmed fallback answer carries meta.source: "furs" and meta.source_status: "fallback", so your code can tell it apart from a normal VIES confirmation. There is no VIES consultation number attached to it, since only VIES itself issues one, which is why a request that carries requester_vat_number skips the register by default and only reaches it when you pass fallback=true. If FURS also cannot confirm the number, Avatcado can serve an eligible stored result with meta.cached: true and 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 source can answer, the request returns a refunded 503 (upstream_member_state_unavailable). Retain the source and original timestamp; stored evidence does not freshly confirm current registration.

Related guides

VAT rate in Slovenia

The standard VAT rate in Slovenia is 22%. Reduced rates: 9.5%, 5%. See all Slovenia VAT rates.

Sources