TelstraClear has agreed to change its approach to telemarketing and audit its compliance with the Fair Trading Act after a Commerce Commission investigation found that it had switched customers to the TelstraClear network without their consent. The practice is known as "unauthorised switching."

In a settlement reached with the Commission, TelstraClear admitted to breaching the Fair Trading Act and agreed to contract an external adviser to audit its compliance procedures.

TelstraClear has already contacted all customers who complained and credited their accounts or closed them with no outstanding balance. It has also changed its approach to telemarketing and customer complaints, and is working with an industry body to develop codes around customer transfer and consumer complaints.

"We are satisfied the changes put in place by TelstraClear address our concerns about unauthorised switching," said the Commission's Director of Fair Trading Deborah Battell.

"Switching companies is a critical competition issue in utility markets," Ms Battell said.

"Unauthorised switching takes the power of choice away from consumers, and that undermines competition.

"Consumers need to have confidence that they can switch companies when they want to, and won't be switched when they don't want to."

The Commission began investigating after complaints from the public. Complaints were also received by TelstraClear, and by the Fair Go television programme.