Customers on Telstra's post-paid contracts will burn through their allowance quicker after the telco announced changes to its post-paid plans.
Telstra has upped its charging blocks for phone calls from 30 second to 1 minute, for standard national voice and video calls.
Users making a call over 1 minute would therefore be charged for a 2 minute call.
"Effective 1st October 2012, standard national voice and video call charging block will change from 30 second to 1 minute blocks (charged at the standard voice/video rates plus connection fee). This means the charge for calls will automatically be rounded up to the nearest minute," the website states.
Telstra warns users will be "more likely to use up more of your allowance quicker due to the changes."
It said the changes make its pricing more "simple and easy to understand" and are in line with charging across all its post-paid mobile plans.