# Rules for generating social security card numbers Social security card numbers are usually generated based on specific rules. In mainland China, social security card numbers generally have the following characteristics： 1. The social security card number is usually 18 digits 2. Most regions use the resident ID number as the social security card number 3. Special coding rules may be used in a few regions ## Specific example Suppose a resident ID number is: **110101199001011234** In most regions, this person's Social Security card number is directly: 110101199001011234 Some regions may have special codes for social security card numbers, such as： - The area code may be added before the ID number: 01110101199001011234 - Independent coding system may be used: SI110120190101XXXX Please note that for privacy reasons, I cannot provide an example of a real Social Security card number. The above is only a format description, and the actual number must follow the specific regulations of the local social security department.