Födelsenummer, also known as Swedish Personal Identity Number, is a national identification number used in Sweden. It is a 10-digit number that contains information about an individual's birthdate and gender.
The format of Födelsenummer consists of the birth date in YYMMDD format, followed by a hyphen, and four additional digits. Upon reaching the age of 100, the hyphen in the format is substituted with a plus sign.
What is the structure of the Födelsenummer?
The first six digits of the Födelsenummer represent the person's birthdate in the format of YYMMDD, where YY is the last two digits of the birth year, MM is the birth month (with an additional 20 added for individuals born after 1999), and DD is the birth day. The next three digits are randomly assigned by the Swedish Tax Agency and are used to uniquely identify individuals with the same birthdate and gender
The final digit is used as a checksum to ensure that the Födelsenummer is valid. The checksum is calculated using the Luhn algorithm, which is a widely used method for validating identification numbers.
The Födelsenummer is used in a variety of applications in Sweden, including for tax and social security purposes, as well as for identification when accessing government services and banking services. It is an important tool for ensuring accurate identification and record-keeping in the country.
How does the checksum calculated?
To calculate the checksum, multiply the individual digits in the 10-digit identity number and 212121-212. Note: For 12-digit numbers, the two first digits are omitted from the calculation.
Example 1: 150913-0421
| 1x2 = 2 |
| 5x1 = 5 |
| 0x2 = 0 |
| 9x1 = 9 |
| 1x2 = 2 |
| 3x1 = 3 |
| 0x2 = 0 |
| 4x1 = 4 |
| 2x2 = 4 |
Sum the individual results
2 + 5 + 0 + 9 + 2 + 3 + 0 + 4 + 4 = 29
The check digit is equal to 10 - (29 mod 10) = 10 - 9 = 1
So the final birth number is 150913-0421
Example 2: 740813-9561
| 7x2 = 14 = 1+4 = 5 |
| 4x1 = 4 |
| 0x2 = 0 |
| 8x1 = 8 |
| 1x2 = 2 |
| 3x1 = 3 |
| 9x2 = 18 = 1+8 = 9 |
| 5x1 = 5 |
| 6x2 = 12 = 1+2 = 3 |
Sum the individual results
5 + 4 + 0 + 8 + 2 + 3 + 9 + 5 + 3 = 39
The check digit is equal to 10 - (39 mod 10) = 10 - 9 = 1
So the final birth number is 150913-0421
Example 3: 651209-1270
| 6x2 = 12 = 1+2 = 3 |
| 5x1 = 5 |
| 1x2 = 2 |
| 2x1 = 2 |
| 0x2 = 0 |
| 9x1 = 9 |
| 1x2 = 2 |
| 2x1 = 2 |
| 7x2 = 14 = 1+4 = 5 |
Sum the individual results
3 + 5 + 2 + 2 + 0 + 9 + 2 + 2 + 5 = 30
The check digit is equal to 10 - (30 mod 10) = 10 - 0 = 10
if 10 is the checksum value then take 0 as the checksum digit.
So the final birth number is 651209-1270
