Telstra will introduce per-minute billing to home phone and some mobile plans from 20 March, 2011.
"We will now bill timed calls in one-minute blocks of time, which means the charge for the call is automatically rounded up to the nearest minute," a Telstra spokesman said.
The spokesman moved to assure customers that the change would not affect "the cost of local calls or call caps on your HomeLine plan, and it won't affect the included cap allowance on your mobile cap plan."
Billing by the minute has been a common feature of mobile phone billing for some time. Rivals Optus and Vodafone charge 90c a minute and a 35c flagfall for voice calls.
Telstra will reportedly charge 80c a minute when it bills in one-minute blocks.
One-minute billing means that a call that runs for one minute and one second is charged the same as a call that runs for one minute and 59 seconds.
Telstra previously charged for calls from mobiles and home phones in 30-second blocks [pdf, page 12].
Optus still appeared to charge for calls on its home phone cap plans in 30-second blocks.
Telstra has reported consistent declines in revenue from its fixed line phone business.