OIB (VAT number) validator — Croatia

Croatia OIB (VAT number) validator

Enter a OIB (VAT number)

How the OIB (VAT number) format works

Format: HR + 11 digits
Example: HR12345678901

Things to watch for

Uses the same 11-digit OIB as the national personal/business ID
This tool checks the format only; the Croatian check digit is not yet validated

Regex for OIB (VAT number)

^HR[0-9]{11}$

Croatia doesn’t issue a separate VAT-only number. Instead, a Croatian VAT identifier is simply “HR” placed in front of the holder’s existing OIB (Osobni identifikacijski broj) — an 11-digit personal or business identification number that Croatia already uses for tax filing, company registration, healthcare, and other government services. A full VAT number looks like HR12345678901: two letters, eleven digits, no exceptions.

That reuse is the detail worth knowing. Where most EU countries mint a VAT number distinct from other tax IDs, Croatia’s VAT-Porezna uprava (tax administration) simply prefixes the same OIB every resident and business already holds. So an 11-digit VAT number and an 11-digit personal OIB aren’t a coincidence — for a sole trader, they can be the identical string of digits.

The format rule

This validator checks for the “HR” prefix followed by exactly 11 digits, which is the full length of an OIB — run entirely in your browser with nothing sent to a server. It’s a structural check only: the OIB’s own official check-digit calculation isn’t implemented here yet, so a pass confirms length and prefix, not the checksum.

Limits of this check

A correctly shaped number isn’t proof of live VAT registration. Confirm current status through the EU’s VIES lookup or Croatia’s Porezna uprava before treating a number as a verified, active registration.

Scope: format and length only — not OIB checksum validation, VAT registration status, or filing rules.

Content last reviewed 2026-07-07.

OIB (VAT number) FAQ

Is a Croatian VAT number the same as an OIB?

Functionally yes — Croatia's VAT number is simply 'HR' placed in front of the person or company's existing 11-digit OIB (Osobni identifikacijski broj), the same master ID used for tax, business registration, and personal identification.

Why is a Croatian VAT number 11 digits when most neighbors use 8 or 9?

Because it's not a VAT-specific number at all — it's the OIB, a general-purpose national identifier issued to every person and legal entity in Croatia, reused here for VAT purposes rather than a separate scheme being created.

Does this tool check the OIB's own check digit?

No — it currently confirms the 'HR' prefix and the 11-digit count only. The OIB does have its own official check-digit algorithm, but this validator doesn't run it yet.