The New Zealand Income Survey is a supplement to the HLFS and as such uses the same sample population. The HLFS sample has approximately 15,000 private households, sampled randomly from rural and urban areas throughout New Zealand. It gathers information for each household member who falls within the scope of the survey and meets the survey coverage rules. The final NZIS dataset has approximately 29,000 individuals. All respondents to the HLFS are asked to participate in the NZIS. The target population of the NZIS is the usually-resident, non-institutionalised civilian population of New Zealand aged 15 and over. This population does not include:

• long-term residents of homes for older people, hospitals, and psychiatric institutions
• inmates of penal institutions
• members of the permanent armed forces
• members of the non-New Zealand armed forces
• overseas diplomats
• overseas visitors who expect to live in New Zealand for less than 12 months
• those aged under 15 years.

New Zealand residents living on offshore islands (except for Waiheke Island), and those temporarily overseas are not surveyed. The survey population is therefore marginally different from the target population.