Definition: The word "National Insurance Number" (NIN) is a unique identifier used by employers to track employee hours worked. It is typically a 12-digit number, consisting of three segments separated by periods. Each segment represents a month or quarter for which the worker has been employed, followed by a numeric value indicating their employment status: part-time, full-time, or casual worker. For example: - Segment A: 09-24-08 means the employee was hired on September 24th, 2008. - Segment B: 17-6-13 means the employee has worked for six months from June 1st, 2013. The NIN is used in various HR systems and applications such as payroll software to track employee hours, pay rates, benefits, and other employment data. It's important to note that the NIN can be tracked by multiple sources independently or together, depending on the specific requirements of each organization.