How South African ID numbers are formed

Everyone knows that South African ID numbers start with date of birth. If you were born on May 13, 1988 then your ID number starts with 880513.

This post details what the rest of the digits in an ID number mean.

The format is:

{YYMMDD} {G} {SSS} {C} {X} {Z}

  • {YYMMDD} is the date of birth
  • {G} is gender. 0-4 is female and 5-9 is male
  • {SSS} is a sequence number
  • {C} is citizenship. 0 for South Africans and 1 for other citizens
  • {X} is usually 8 or 9 – not clear what this is
  • {Z} is a check digit calculated from the other digits

So for the ID number 8909025012083 we know certain things about the person:

  • Born on September 2nd, 1989
  • Male
  • 12th male born on that date to get an ID number
  • South African citizen

Not very useful, but interesting.

  • BOB

    This is really interesting. Could you find an example of an ID no in 1899 and one in 1999.

  • Fred

    {X} used to be population group. All ID Numbers now use 8.

  • Deebeee

    Interesting Fred as here in the UK we are almost always asked by government departments which ethnic group we belong to, while you in SA very sensibly ignore such an irrelevance!

  • Ng

    It is really interesting. But I am not getting {Z} sill.

  • Evan James Knowles

    Not certain if anyone’s still interested, but here’s my write up on generating / validating ID numbers, along with a Chrome extension for convenience while developing:

  • Edith

    Mine ends in 006 what does that mean?