Nomor Induk Kependudukan
Indonesia · Individuals
Paste or type the number — punctuation is optional.
Other identifiers
Europe
Asia and the Middle East
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What this check does — and what it cannot do
This tool checks the number's structure and its check digit, using the published algorithm for that document. A number that passes is well formed: it is arithmetically consistent and could have been issued.
It cannot tell you whether the number was actually issued, whether it is active, or who it belongs to. Only the issuing tax authority can confirm that, through its own lookup service. Treat a passing result as "worth submitting", never as proof of identity.
How the NIK check works, and what the number tells you
A NIK is a personal identity number issued in Indonesia. This page checks one against the published rule, shows which specific test it fails when it fails, and decodes the facts the digits carry. Everything runs in your browser — the number you type is never sent anywhere.
How it works
- Applies the published checksum rather than only checking the length and shape.
- Names the exact rule that failed, so a typo is distinguishable from a number that was never valid.
- Decodes what the number encodes: province code, regency code, date of birth, sex.
- Does not generate numbers. This one identifies a person, and a page that manufactures plausible identity numbers is a liability rather than a feature.
16 digits: PP RR DD DDMMYY SSSS PP province RR regency or city DD district date of birth, with 40 ADDED TO THE DAY for women SSSS sequence within that district and date There is no check digit at all, so the only tests possible are the structural ones: a province code that is not 00, and a date that exists once the 40 has been removed.
Worked example
Checking 3171014501990001, a valid NIK, digit by digit.
- input 3171014501990001
- Province code 31
- Regency code 71
- Date of birth 05-01-99
- Sex Female
- Checksum None — a NIK has no check digit
- result passes every published check
The checksum passes, so the number is internally consistent, and the tool reads off province code, regency code, date of birth, sex. Internal consistency is not the same as the number being issued to somebody — see the note below.
Reading the result
- Adding 40 to the day of birth is how a NIK encodes sex, which means the date and the sex are not independent fields — you cannot change one without changing the other. It also means a day between 41 and 71 is normal rather than an error.
- A passing checksum means the digits are consistent with each other, not that the number exists. Only Indonesia's own registry can tell you whether a number was actually issued and is still valid, and no offline tool can substitute for that.
- The check happens entirely in your browser. Nothing is uploaded, logged, or stored, which matters more here than on most tools because these numbers are personal data in every jurisdiction that issues them.
- Punctuation is ignored. Spaces, dots, dashes and slashes are stripped before the check, so a number pasted in any common local format is read the same way.
Common questions
- My number is real but this says it is not valid. Why?
- Check for a transposed pair of digits first — that is the single most common cause, and every checksum here is designed to catch it. Failing that, the number may predate the current rule: several countries changed or introduced their checksum at a known date, and older numbers were not reissued. If the tool names a specific rule that failed, that is the one to look at.
- Does a valid result mean the number is registered?
- No, and this is the limit worth understanding. A checksum proves the digits are mutually consistent, which catches typos and made-up numbers. It cannot prove the number was issued, is still active, or belongs to the person quoting it. Only the issuing authority's own lookup can do that.