Croatia OIB Validator
Validate Croatian ID
Enter a Croatian Identification Number to verify its validity.
About this Validator
This tool validates Croatian Personal Identification Numbers (Osobni identifikacijski broj) according to official format requirements.
The validator checks if a given OIB follows the correct structure and verifies the check digit using ISO 7064 Mod 11,10 algorithm.
This validation only confirms if an OIB follows the correct format. It does not verify if the number is actually registered with Croatian authorities.
What is a Croatian Personal Identification Number (OIB)?
OIB Structure: • Total length: 11 digits • Optional HR prefix • Random sequence of digits • Last digit: Check digit • Format: XXXXXXXXXX or HR XXXXXXXXXX
Validation Features: • ISO 7064 Mod 11,10 algorithm • No embedded personal data • Purely numerical format • Check digit verification
Used for: • Personal identification • Business registration • Tax purposes • Government services • Financial transactions
If you need to generate an OIB for testing purposes, here is a Croatian OIB Generator