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Check the VAT ID before you quote without VAT.

Enter the number and see right away whether its format and check digit are correct. For Austria, Germany and Switzerland, no sign-up needed.

Enter a number, for example ATU13585627 or DE136695976.

The check runs in your browser; the number is not sent anywhere.

What the check shows

Every VAT ID (in Austria: UID-Nummer) follows a fixed format, and its last digit is a check digit calculated from the others. A typo almost always changes the check digit, so the tool catches swapped or missing digits before the number lands on a quote.

Only the tax authorities can say whether a number has actually been issued and is valid. For businesses in the EU, look it up in the European Commission's VIES system. In Austria, a level 2 lookup in FinanzOnline also returns the name and address, plus a confirmation you should keep.

When the VAT ID belongs on the quote

  • Your own VAT ID goes on every invoice over €400 (Austria) and on every quote you lay out like an invoice.
  • The customer's VAT ID is required for reverse charge and for intra-Community supplies.
  • In Austria, an invoice over €10,000 gross needs the customer's VAT ID even for domestic sales.

PrestoCRM checks the format of every VAT ID as you type it and warns you on reverse charge quotes when the customer's VAT ID is missing.

Frequently asked questions

What does an Austrian VAT ID (UID) look like?

ATU followed by eight digits, for example ATU13585627. The last digit is a check digit calculated from the seven digits before it.

Does a correct check digit mean the number is valid?

No. The check digit shows that the number could have been issued. Whether it actually was issued, is active and which business it belongs to is answered by a VIES lookup or, for a confirmed lookup in Austria, by FinanzOnline.

When do I have to check my customer's VAT ID?

Before every VAT-exempt service or delivery to a business in another EU country (reverse charge, intra-Community supply). If the VAT ID is invalid, you may be liable for the VAT you did not charge.

What do German and Swiss VAT IDs look like?

Germany: DE and nine digits (Umsatzsteuer-Identifikationsnummer, issued by the Federal Central Tax Office). Switzerland: CHE-123.456.789 with the suffix MWST, TVA or IVA; Switzerland is not in VIES, numbers are checked in the UID register.

Sources (as of October 2026)

These tools are no substitute for tax advice. Check special cases with your tax advisor.