PIB, the tax identification number
Companies, entrepreneurs, permanent establishments and non resident natural persons have a PIB with 9 digits: an 8 digit serial number from 10000001 to 99999999 and one control digit. The PIB rulebook says the control digit is calculated from the first eight by the ISO 7064, MOD 11,10 method.
For residents who are not entrepreneurs, the PIB is their JMBG with 13 digits. The tool does not check JMBG numbers, because they are personal data.
MB, the company registration number
The registration number of a company (matični broj, MB) has 8 digits. Neither NBS nor APR publishes an official method for its control digit that we could find. The tool uses the method that software commonly uses and that works on every real number we checked:
When the result is 10 the control digit 0 is not confirmed on a real number, so the tool marks such numbers for checking instead of calling them valid. Treat any MB result as a hint for typing mistakes, not as an official answer.
Bank account number
By the NBS decision on the uniform structure of current accounts, an account number has 18 digits in three parts: 3 digits for the bank, 13 for the account and 2 control digits. The control number follows ISO 7064, MOD 97:
On paper the three parts may be separated by dashes and the zeros at the start of the middle part may be left out. Electronically the number always has all 18 digits. For example, 840-955845-10 from the NBS recommendations is 840000000095584510.
Bank codes
The first three digits show the bank. This is the NBS list of 8 September 2026. After a merger the bank that takes over may keep using the old code for a while, so the tool calls an unknown code a warning, not a mistake.
| Code | Bank |
|---|
A valid number is not a checked company
Control digits only catch typing mistakes, such as a wrong or swapped digit. They do not tell you whether a company exists, is active or owns the account. To check a company, look it up in the register of the Business Registers Agency (APR), and take account numbers from the company's invoices or contract.
FAQ
Is anything I paste sent or saved?
No. The check runs in your browser. The list is not sent anywhere and is gone when you close the page.
Can I check a JMBG here?
No. A JMBG is personal data, so we left it out. When a line has 13 digits, the tool says it is not checked.
The account is valid but the bank is unknown. Why?
The code is not on the NBS list of 8 September 2026. That can happen after a merger, when the new bank keeps using the old code for a while, or when the number is old. Ask the company to confirm its account.
Where do the examples come from?
The PIB 100041150 and MB 07007965 belong to the National Bank of Serbia and are published in its information booklet. The PIB 103445385 and MB 17580175 belong to APR and are on its website. The accounts 840-955845-10 and 165-55-74 are examples from the NBS recommendations. The list also has numbers with deliberate mistakes.
Sources: PIB rulebook, article 2 (consolidated text on paragraf.rs), National Bank of Serbia decision on the uniform structure of current accounts and decision on the codes of payment service providers of 8 September 2026, NBS recommendations for the account examples, the NBS information booklet and apr.gov.rs for the PIB and MB examples. Checked in October 2026.
This tool only checks how numbers are built. It is not legal or tax advice and does not replace a check in official registers.
The tool only uses what you enter. Nothing is sent or stored.