What does a JMBG encode?

The first seven digits are the date of birth (DDMMGGG), the next two are the region code, the next three are a serial that also encodes gender (under 500 = male, 500 and over = female), and the last is a modulo-11 check digit.

Does a valid JMBG mean the person is registered?

No. The checksum only confirms the number is internally consistent — it does not validate against any population register.

No. All decoding happens locally in your browser and nothing is sent anywhere.

How is gender encoded in a JMBG?

The three-digit serial after the region code (positions 10–12) carries it: a value under 500 indicates male and 500 or above indicates female.

How is the JMBG check digit calculated?

It is a modulo-11 checksum over the first twelve digits using the weights 7 6 5 4 3 2 7 6 5 4 3 2. Compute m = 11 minus the weighted sum mod 11; m from 1 to 9 is the check digit, and 10 or 11 becomes 0.

Is the JMBG used outside Serbia?

Yes. The same 13-digit format originated in Yugoslavia and is still used or was used in several successor states, including Bosnia and Herzegovina, North Macedonia, Montenegro and others, with differing region codes.

Serbia JMBG Decoder — Gera Tools

Serbian JMBG decoder

The JMBG (Jedinstveni matični broj građana) is a 13-digit identifier used across Serbia and the former Yugoslavia. Paste a number and this tool reads the date of birth, region of registration and gender, and verifies the check digit — useful for developers validating ID input or anyone curious what a JMBG encodes.

How it works

The 13 digits follow the pattern DDMMGGG RR BBB K:

Segment	Meaning
DDMMGGG	Date of birth — day, month, and last 3 digits of the year
RR	Region / registration code
BBB	Serial 000–999; under 500 = male, 500 and over = female
K	Modulo-11 check digit

The implied century is reconstructed from the three year digits (800–999 → 1800s/1900s, 000–799 → 2000s). The check digit validates the first twelve digits with weights 7 6 5 4 3 2 7 6 5 4 3 2: multiply, sum, take m = 11 − (sum mod 11); if m is 1–9 the check digit is m, and if m is 10 or 11 the check digit is 0.

Example

For a JMBG beginning 0101990…, the first seven digits decode to 1 January 1990, the serial determines gender (e.g. 123 → male), the RR pair maps to a region such as central Serbia, and the final digit is checked against the modulo-11 formula.

All decoding runs in your browser, with nothing uploaded. A valid check digit confirms only that the number is internally consistent, not that it is registered to a real person.