What does a Romanian CNP encode?

The first digit encodes sex and century, the next six are the date of birth, two digits give the county (județ), three are a serial, and the final digit is a modulo-11 checksum.

How is the CNP check digit calculated?

Multiply the first twelve digits by the constant weights 2,7,9,1,4,6,3,5,8,2,7,9, sum them, and take the sum modulo 11. If the remainder is 10 the check digit is 1, otherwise it is the remainder.

Is my CNP sent to a server?

No. The decoder runs entirely in your browser with client-side JavaScript — your CNP is never uploaded or stored.

What does the first digit of a CNP mean?

It combines sex and century of birth: 1 = male and 2 = female born 1900–1999; 3/4 born 1800–1899; 5/6 born 2000–2099; and 7/8 for resident foreigners. So a CNP starting with 2 is a woman born in the 1900s.

Does a valid check digit mean the CNP is real?

No. The check digit only confirms the number is internally consistent. It cannot tell you whether the CNP belongs to a registered person — only the authorities can confirm that.

Where is the county encoded?

Digits 8 and 9 (after the six date digits) give the județ (county) code where the number was issued, from 01 to 52 plus codes for Bucharest sectors. The decoder maps that code to the county name.

Romania CNP Decoder — Gera Tools

A Romanian CNP (Cod Numeric Personal) is a 13-digit national identification number that encodes a person’s sex and century of birth, their date of birth, the county where the number was issued, a serial, and a check digit. This tool decodes each field and verifies the checksum, entirely in your browser.

How it works

The 13 digits follow the pattern S AA LL ZZ JJ NNN C:

S — sex + century (1/2 = 1900s, 3/4 = 1800s, 5/6 = 2000s, 7/8 = resident foreigner)
AA LL ZZ — two-digit year, month, day of birth
JJ — county (județ) code
NNN — serial number
C — check digit

The check digit is verified by multiplying the first twelve digits by the fixed weights 2, 7, 9, 1, 4, 6, 3, 5, 8, 2, 7, 9, summing the products, and taking the sum modulo 11. If the remainder is 10 the check digit should be 1; otherwise it equals the remainder.

Example

Take a CNP beginning 1980229...:

First digit 1 → male, born 1900s
Next six 800229 → 29 February 1980
The following two digits give the county, then a serial, then the check digit, which the tool validates against the weighted-sum rule.

Field	Position	Example
Sex + century	1st digit	1 → male, 1900s
Date of birth	digits 2–7	800229 → 1980-02-29
County	digits 8–9	mapped to județ
Check digit	13th digit	mod-11 verified

The CNP you enter is never uploaded; this is a structure and checksum decoder, not a registry lookup.