Icelandic Kennitala Validator
National identification number for individuals and companies in Iceland (Þjóðskrá).
About Icelandic Kennitala
The universal personal and business ID in Iceland.
Managed by Registers Iceland (Þjóðskrá Íslands).
Anatomy of Icelandic Kennitala
10 digits in DDMMYY-SSDC format:
| Position | Field | Length | Meaning | Example |
|---|---|---|---|---|
| 1 to 2 | Day (+40 for Companies) | 2 digits | Day (01-31) or Day + 40 for businesses (41-71) | 01 |
| 3 to 4 | Month | 2 digits | Month of birth or registration (01-12) | 01 |
| 5 to 6 | Year | 2 digits | Last two digits of the year (YY) | 30 |
| 7 to 8 | Sequence | 2 digits | Random sequence digits (20 to 99) | 29 |
| 9 | Check Digit | 1 digit | Weighted Modulo 11 check digit | 8 |
| 10 | Century Digit | 1 digit | 8 (19th century), 9 (20th century), 0 (21st century) | 9 |
Official Modulo 11 Algorithm
Standard calculation by Þjóðskrá Íslands:
Sum = Σ(d[i] * w[i]); Remainder = Sum mod 11
- 1. Multiply the first 8 digits by weights [3, 2, 7, 6, 5, 4, 3, 2].
- 2. Calculate remainder of sum divided by 11.
- 3. If remainder is 0, check digit is 0.
- 4. If remainder is 1, combination is discarded (invalid).
- 5. If remainder > 1, check digit is 11 - remainder.