What an OIB is
The OIB (osobni identifikacijski broj) is Croatia's personal identification number. Every person and company dealing with Croatian authorities, banks or notaries has one. It is issued by the Croatian Tax Administration (Porezna uprava) and stays the same for life.
As a foreigner you will typically need an OIB to buy or sell property, sign a long-term lease, open a bank account, register a car, start a business or receive income in Croatia. Notaries, banks and estate agents will ask for it early in the process.
How the check works
An OIB has 11 digits. The first ten are assigned at random and the eleventh is a control digit calculated from the first ten using ISO 7064 (MOD 11,10). The tool repeats the calculation and compares the result with the last digit. If they don't match, the OIB was definitely entered incorrectly.
How foreigners get an OIB
You can apply for an OIB at any branch of the Croatian Tax Administration, or through a Croatian embassy or consulate abroad. You will usually need a valid passport or national ID card and a completed application form. Requirements and forms can change, so check the current rules on the Tax Administration's website (porezna-uprava.gov.hr) or ask the embassy before you go.
What the check doesn't do
The tool does not reveal who an OIB belongs to and does not confirm that a number has actually been issued. A correctly structured number may still not exist. Personal OIBs are personal data, and there is no public lookup for private individuals. Companies can be looked up in the Croatian court register (sudreg.pravosudje.hr).
Frequently asked questions
Do EU citizens need an OIB?
Is an OIB the same as a tax number?
Can this tool show whose OIB it is?
Do you store the OIB I enter?
Updated: November 2026 · Supremio Digital, Zagreb
