Understanding South African ID Numbers
Every South African ID number follows a specific format that contains important information about the holder. The colour-coded breakdown below shows what each segment means.
Birth date
790307
Gender
5289
Citizen
0
Register
8
Checksum
0
Birth date (YYMMDD)
Digits 790307 represent 1979/03/07.
Gender & sequence (SSSS)
Digits 5289 encode gender and birth-registration sequence. Values 0000–4999 indicate female; 5000–9999 indicate male. For this number: Male (sequence 5289).
Citizenship (C)
Digit 0 indicates citizenship status: SA Citizen.
Population register index (A)
Digit 8 is the standard population-register index under the Identification Regulations (regulation 3(e)).
Luhn checksum (Z)
Checksum digit 0 matches the Luhn formula for the first 12 digits, confirming structural validity.
What do these numbers mean?
A South African ID number is a 13-digit number that uniquely identifies an individual. Each group of digits in the ID number has a specific meaning:
- Date of Birth (First 6 digits): YYMMDD format
- Gender (Digits 7-10): 0000-4999 for females, 5000-9999 for males
- Citizenship (Digit 11): 0 for SA citizens, 1 for non-SA citizens, 2 for refugees
- Population register index (Digit 12): Normally 8; digit 9 when the daily unique-number allocation for that birth date is exhausted
- Checksum (Digit 13): Verification digit that confirms the first 12 digits form a valid number. This is what our ID validator tool does.
This numbering system helps prevent fraud and ensures each ID number is unique. The checksum digit at the end helps verify if an ID number is valid by using a mathematical formula.
The structure above follows regulation 3 of the Identification Regulations, 1998 (under the Identification Act, 1997). CheckID validates the number format and checksum against this published structure; we do not query Home Affairs or any government database.
Need to validate ID numbers at scale?
Our tool instantly verifies the format, age, gender, and checksum of any South African ID number.
Frequently Asked Questions
How can I tell if an ID number is valid?
A valid South African ID number must:
- Be exactly 13 digits long
- Have a valid date of birth in the first 6 digits
- Have a valid gender sequence number (0000-9999)
- Have a recognised citizenship digit (0, 1, or 2)
- Have a matching checksum digit
Can ID numbers be changed?
No, South African ID numbers are permanent and cannot be changed. They are unique identifiers assigned at birth or when citizenship/permanent residence is granted. If there are errors in your ID number, you need to contact the Department of Home Affairs to have it corrected.
What if my ID number doesn't follow this format?
If your ID number doesn't follow this format, it might be invalid or from a different era. The current 13-digit format was introduced in the 1970s. If you're concerned about your ID number, contact the Department of Home Affairs for verification.
Related ID validation resources
5-Minute API Integration Guide
Learn how to programmatically validate South African ID numbers using our API with code examples in JavaScript, PHP, and Python.
South African ID Number Structure
Digit-by-digit reference with a worked example and validation boundaries.
SA ID Checksum Explained
Step-by-step Luhn checksum walkthrough and common failure patterns.
ID Validator API
Use structural ID validation inside your own software with single and bulk endpoints.
Complete API Documentation
Full API reference with authentication, endpoints, and error handling for building ID verification into your applications.