OIB, IBAN and reference check
Three small checks for Croatian payments and forms. Everything is worked out on this page.
- Runs in the browser. Nothing typed here is sent or stored.
- A passing check shows the number is well-formed, not that the person, account or payment exists.
- The reference rules follow the HUB overview of basic reference models (HR01 to HR04).
Questions
What does the OIB check actually prove?
That the 11 digits are well-formed: the last digit matches the first ten (ISO 7064, MOD 11,10). It catches a mistyped digit. It does not say whether the OIB was ever issued or to whom.
Can I use a generated OIB?
Only as test data in forms, databases and demos. It is random, so it can by chance be a real person's OIB. Do not use it on any real document or filing.
How do I know the bank from an IBAN?
In a Croatian IBAN, digits 5 to 11 are the bank's code. The page looks it up in the Croatian National Bank's list; a bank missing from the list just shows no name, which does not make the IBAN invalid.
Which reference model should I use?
The one the payee asks for, or the one their invoicing software uses. HR01 is the simplest: one control digit for the whole number. Other models (such as HR05, which involves an OIB) are not covered here.
These tools are free and provided as they are. They are made with care, but they are not guaranteed to be free of errors or to suit every purpose, and they are used at the user's own responsibility. Please check the result before relying on it: scan the code, confirm the payment details, and where it matters ask the recipient or an adviser. To the extent permitted by law, Broken Logic Studio is not liable for loss or damage arising from the use of the tools. A passing check shows only that a number is well-formed. It does not confirm that a person, company, account or payment exists, and a generated OIB is test data only. Confirm payee details with the payee.