What is a ‘unique identifier’?
Some agencies give people a ‘unique identifier’ instead of using their name. Examples are a driver’s licence number, a passport number, a student ID number, or an IRD number. Principle 13 of the Privacy Act regulates unique identifiers.
The key rules for unique identifiers are:
- An agency can only assign a unique identifier to people if it is necessary for that agency to carry out one of its functions.
- An agency cannot assign a unique identifier to a person if that unique identifier has already been given to that person by another agency.
- Agencies must take all reasonable steps to make sure unique identifiers are accurate and not misused.
- People are not required to disclose their unique identifier unless this is one of the purposes for which the unique identifier was set up (or directly related to those purposes).
Updated October 2025