How an EGN is structured
The unified civil number (ЕГН) has 10 digits in the form YY MM DD RRS C:
- YY MM DD — birth date. For people born 1800–1899, 20 is added to the month; for people born from 2000 onwards, 40 is added. For example, born 15 July 2010 → 10 47 15.
- RRS — a unique combination for the day, a number from 000 to 999. The last digit (the 9th of the EGN) encodes sex: even for male, odd for female.
- C — a check digit computed from the first nine.
How the check digit is computed
Each of the first 9 digits is multiplied by its weight: 2, 4, 8, 5, 10, 9, 7, 3, 6. The products are summed and the sum is divided by 11. The remainder is the check digit; if the remainder is 10, the check digit is 0.
Example: for the first nine digits 104715624 the sum is 1·2 + 0·4 + 4·8 + 7·5 + 1·10 + 5·9 + 6·7 + 2·3 + 4·6 = 196. Since 196 = 17·11 + 9, the check digit is 9 and the full number is 1047156249 (male, born 15 July 2010).
How accurate is the region?
The region comes from the widely used table of ranges for the three digits after the date. That table reflects older practice: the current regulation (Art. 104 of Regulation No. RD-02-20-9/2012) describes these digits only as a unique combination for the day. So the region is indicative only, and for people born after 2000 you shouldn't rely on it.
What “valid” means
Valid means the date exists and the check digit is correct. It does not mean the number has been issued, or that it belongs to a particular person.