Unique Student Identifier


A unique student identifier is typically a number or code assigned to students enrolled in public schools that allow state education agencies, districts, schools, collegiate institutions, researchers, and others to monitor, track, organize, and transfer student records more efficiently and reliably. In the United States, state education agencies assign a randomly generated series of numbers and/or letters to individual students, with each student assigned one unique identifier. One of the primary advantages of a unique student identifier is that it’s used in place of a student’s name or other personal information that may compromise the privacy or reveal the identity of the student. For privacy-related reasons, social security numbers are generally not used as unique student identifiers in the United States, and several states have even passed laws that explicitly forbid the use of social security numbers as unique student identifiers.

It should be noted that different terms may be used when referring to unique student identifiers in education, including statewide student identifier, student identification number, or student ID, among others. Because these terms may or may not be used synonymously in certain technical contexts, it is important to determine precisely how the term is being defined when investigating or reporting on student data.

In addition to protecting student privacy, unique student identifiers are used to improve the quality, accuracy, and reliability of student data. By assigning students unique identifiers, a wide variety of educational records maintained by different educational agencies, schools, or programs—from report cards and test scores to disciplinary records and school-attendance data to learning-disability assessments and special-education plans—can be reliably associated with individual students in the vast, complex data systems that track information related to tens or hundreds of thousands of students enrolled in a public school in a given state.

Once a unique student identifier has been assigned, it remains attached to the student as long as he or she is enrolled in public school. The same unique identifier is used if a student transfers from one school district to another in a state, and it will remain in use if a student moves out of state for a period of time and then returns to the state. Because unique student identifiers are generated for use in a specific state’s educational data system, students will be assigned a different identifier when they enroll in different state’s public-education system. The United States does not use unique student identifiers at the national or federal level.

In some states, young children enrolled in state-subsidized prekindergarten programs may be assigned unique student identifiers that will stay with the students when they enroll in public school, while other states may not yet assign unique student identifiers to preschool students for any number of reasons (e.g., they may not have data systems capable of assigning and tracking unique student identifiers for preschool students, or they may lack the necessary staffing or funding). Postsecondary institutions—both public and private colleges and universities—have historically used social security numbers as their unique student identifiers. Some state agencies of higher education, however, do use public-school student identifiers in collegiate records (a practice that facilitates the transfer of student data between public schools and postsecondary institutions), but unique student identifiers are only used for students who graduated from in-state public high schools.

Unique student identifiers are often considered essential for the effective management of student-level data in longitudinal data systems—i.e., data systems that are used to track information over long periods of time, such as years or even decades. Because data related to an individual student may be stored in multiple data systems across multiple districts, schools, and state agencies, unique student identifiers are seen as the most accurate way to link individual student records across all the different data systems tracking students over multiple years. The use of unique student identifiers can also, for example, improve the speed with which transcripts and other records are transferred among schools, in addition to other benefits.

When working with large sets of data from multiple schools or across multiple academic years, maintaining data quality, accuracy, and reliability is an enormous challenge. Unique student identifiers can improve data quality by ensuring that individual students are consistently identified in a wide variety of databases, files, or reports. For example, districts and schools may inadvertently record a student’s name differently—e.g., Tommy Smith may have previously been enrolled in his previous school as Thomas E. Smith. Or there may be multiple Tommy Smiths enrolled in the same school and same grade level at the same time.


Although unique student identifiers can improve the accuracy and reliability of student data, and facilitate the transfer of data reliably across different systems, unique student identifiers also raise concerns about student privacy. For a more detailed discussion of privacy concerns and related debates, see personally identifiable information.

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