The Tax Office is celebrating the considerable uptake of its voice biotmetrics.

Nearly three million tax-payers can now identify themselves using only their voice, according to acting digital program assistant commissioner Venetia Blackman.

“We were looking for a secure, fast and easy way for our clients to authenticate and voice biometrics technology met these needs,” Ms Blackman told reporters.

“The ATO recognised that clients don’t want to be on a call for longer than they need to, but we needed to ensure that convenience and ease of access is effectively balanced with our mutual need for security.”

The Tax Office looked to voice biometrics as an easy way to achieve multi-factor authentication.

“Where the other factors of authentication may be replicated or stolen – something you have and something you know such as a username and password – biometrics, including voice, are something you are and are therefore not able to be easily replicated or easily stolen,” Ms Blackman said.

The ATO use software from natural language firm Nuance, which is also responsible for the ATO’s virtual assistant Alex.

It creates voiceprints based on a number of different markers to establish identity, after being consensually captured from users who sign up for the service.

Uses are asked to say a specific passphrase – “in Australia my voice identifies me” - in the contract centre, before the is used to establish identity through natural conversation.

The service is on track to reach four million by the end of 2018.