About custom audience lists

Custom audience lists helped us direct messages to specific customers with relevant information and reminders. This included letting them know about entitlements like Working for Families, or telling them when they had returns or debt due. This enhanced our ability to ensure taxpayers met their obligations and received their entitlements.

Examples of custom audience advertising are:

• Student loan customers where we could separate the audiences for accuracy, so customers based overseas were reminded about the repayment dates, while customers based in New Zealand received relevant messages if they were self-employed or earned a salary or wage.
• GST customers who had returns and/or a debt due.
• Working for Families customers who may have qualified for certain entitlements or were reminded that they needed to update their information if they had a change in circumstances.

By using these lists we were able to direct advertising to those customers who needed to see the message and we were also able to reach them on a platform they used such as Facebook.

The custom audience feature allows businesses and government departments to upload de-identified information (referred to as hashed information) to the platform, for direct marketing purposes.

A list of identifiers was uploaded into our browser belonging to individuals that we wanted to target with ads. This data was hashed within our browser before being uploaded to the social media platform.

Identifiers used included first name, surname, date of birth, email address, phone number, city, postal code and country.

The custom audience is the list of customers we could then target relevant advertising with. We were not able to see who ends up in this matched list, just the approximate number of people in the audience.

How custom audience lists were loaded

If customers had not given information to the social media platform or do not have an account with them, the hashed data will not match and is deleted.

When we uploaded the file of information to the social media platforms it went through a process called hashing, which de-identified the data. Hashing is a process of scrambling raw data into a fixed-size string of seemingly random characters called a hash and is a commonly used technique in day-to-day digital life e.g. logging into a banking app or checking the integrity of a file you download from the internet.

To ensure the transfer of the hashed data was safe, we used additional transport layer security using recognised encryption channels. The hashed data was uploaded in a process that connects machine to machine with no human intervention.

The hashed data from our list was only used if it could be matched with information customers had already provided on their social media accounts.

You might still see advertising from us such as on a billboard or an advert on social media, but we do not use custom audience lists for these.

We advertise on social media without using custom audience lists. For example, when we needed to reach customers to let them know about the support available during Cyclone Gabrielle, we used geographic targeting in social media platforms to display adverts only to people in the affected regions.