What does a South African ID number encode?

The 13 digits break down as YYMMDD SSSS C A Z: the first six are the date of birth, the next four are a gender serial (0000–4999 female, 5000–9999 male), the eleventh digit is citizenship (0 = citizen, 1 = permanent resident), the twelfth is a historical digit usually 8 or 9, and the last is a Luhn checksum.

How is the year's century determined?

The ID stores only a two-digit year. The decoder infers the century by comparing it with the current year — if the two-digit year is greater than this year's last two digits it assumes 1900s, otherwise 2000s. Very old numbers may need manual interpretation.

How does the Luhn check digit work here?

The first 12 digits are run through the standard Luhn algorithm anchored from the right: starting at the rightmost body digit, every second digit is doubled (and reduced by 9 if over 9), all are summed, and the check digit is (10 minus the sum modulo 10) modulo 10.

How is gender encoded?

The four-digit serial after the birth date determines gender — a value from 0000 to 4999 indicates female and 5000 to 9999 indicates male.

Can it tell if someone is a citizen or resident?

Yes. The eleventh digit is 0 for a South African citizen and 1 for a permanent resident. Any other value is shown as unknown.

Is my ID number uploaded anywhere?

No. The decoder runs entirely in your browser with client-side JavaScript — your ID number is never uploaded or stored.

South Africa ID Number Decoder

A South African ID number is 13 digits that pack four pieces of information into a single string: the holder’s date of birth, gender, citizenship status, and a final Luhn check digit. This decoder reads each field and verifies the checksum so you can catch a transposed digit at a glance.

How it works

The number follows the layout YYMMDD SSSS C A Z:

YYMMDD is the date of birth. The two-digit year’s century is inferred against today’s date.
SSSS is a gender serial: 0000–4999 means female, 5000–9999 means male.
C is citizenship: 0 = South African citizen, 1 = permanent resident.
A is a historical digit, now usually 8 or 9 and ignored.
Z is a Luhn check digit computed over the first 12 digits, anchored from the right (rightmost body digit doubled first), making the whole number pass the modulo-10 test.

Example

Take 8001015009087:

Segment	Digits	Meaning
Birth date	800101	1 January 1980
Gender serial	5009	Male (≥ 5000)
Citizenship	0	SA citizen
Check digit	7	Matches the Luhn expectation

The decoder confirms the final 7 is the correct Luhn digit, so the number is structurally consistent.

Everything runs in your browser, so the ID number you enter is never uploaded. This is a structure and checksum decoder only — it does not confirm the number against the Department of Home Affairs.