International · Validation
Icelandic kennitala validator.
Check a 10-digit Icelandic kennitala: date part, individual or organisation, check digit and century marker. Format and checksum only.
How it works: a kennitala is DDMMYY-RRCK. For organisations 40 is added to the day. Digits 1–9 multiplied by 3, 2, 7, 6, 5, 4, 3, 2, 1 must sum to a multiple of 11 (the ninth digit is the check digit), and the last digit is the century: 9 for 1900s, 0 for 2000s.
Inputs
Result
Enter a number and press Check.
How the kennitala is built
Icelandic law defines the kennitala as a unique identifier for individuals in the national registry. The structure below is as implemented by python-stdnum: DDMMYY-RR C K where DDMMYY is a date, RR two serial digits, C the check digit and K the century marker.
| Digits | Meaning |
|---|---|
| 1–2 | Day. For organisations, 40 is added (41–71) |
| 3–4 | Month |
| 5–6 | Year, two digits |
| 7–8 | Serial digits |
| 9 | Check digit |
| 10 | Century: 9 = 1900s, 0 = 2000s |
Check digit: the weights 3, 2, 7, 6, 5, 4, 3, 2, 1 are applied to digits 1–9 and the sum must be divisible by 11. Worked example from python-stdnum: 120174-3399 gives 1×3 + 2×2 + 0×7 + 1×6 + 7×5 + 4×4 + 3×3 + 3×2 + 9×1 = 88, and 88 = 8 × 11. The organisation example 450401-3150 sums to 66 = 6 × 11 and decodes to 5 April 2001.
Not covered
Icelandic law also mentions system kennitölur (kerfiskennitölur) that Registers Iceland can issue to some foreign nationals. This tool does not model them and may report them as invalid. Century markers other than 9 and 0 are rejected.
Format and checksum only — not a registry lookup
A passing result means the number is well formed. It does not show it was issued, and nothing is sent to any registry.
Icelandic Kennitala FAQ
How do I tell a company kennitala from a personal one?
In the structure python-stdnum implements, an organisation kennitala has 40 added to the day, so the first two digits run from 41 to 71. This tool shows which type it detects.
What does the last digit of a kennitala mean?
It is the century marker: 9 for the 1900s and 0 for the 2000s. It does not take part in the check-digit sum.
Can I look up the owner of a kennitala here?
No. The tool checks structure in your browser and contacts no registry. Companies can be searched in the official Company Registry run by the Icelandic tax authority.
Official register
To confirm a number is real, use the official source: Registers Iceland (Þjóðskrá Íslands). Only the national registry can confirm that a kennitala was issued. Companies can be searched in the Company Registry at skatturinn.is.
Sources
- python-stdnum, stdnum/is_/kennitala.py (weights, +40 organisation offset, century digit, doctest numbers); retrieved October 2026
- Althingi, Act no. 140/2019 on the national registry (defines the kennitala; does not state the check arithmetic); retrieved October 2026
Privacy and scope
This tool runs entirely in your browser: nothing you type is transmitted, stored, or logged, and it queries no government or commercial register. It checks format and checksum only and does not imply any official verification. Do not enter identity numbers belonging to other people that you have no reason to hold.