Service number

A service number or roll number is an identification code used to identify a person within a large group. Service numbers are most often associated with the military; however, they also may be used in civilian organizations. National identification numbers may be seen as types of service numbers.

The term "serial number" is often seen as a synonym of service number; however, a serial number more accurately describes manufacture and product codes, rather than personnel identification. In the Canadian military, a "serial number" referred to a unique number assigned each unit that mobilized for the Second World War.