The population for the AES 2012 financial year was 439,563 units, consisting of:

• 310,527 (70.6 percent) sourced from IR10 information
• 15,796 (3.6 percent) sourced from the postal survey
• 4,976 (1.1 percent) sourced from other government data
• 485 (0.1 percent) sourced from Ministry of Business, Innovation, and Employment data
• 107,779 (24.5 percent) non-sample units.

In the AES 2012, the postal survey unit responses were weighted to represent the non-sample units. The corporate response rate required for the postal collection is set at 85 percent of the industry's goods and services tax (GST) sales. The response rate in 2012 was 91 percent.