The following dial codes can be used to change the amount of time your phone will ring for before going to message bank.
Please note these codes only apply to mobile phones on the Telstra, Optus and Three mobile phone networks.
xx = time in seconds, up to 30 but must be in 5 second increments (i.e. 5, 10, 15, 20, 25, 30).
For example, a Telstra mobile phone would dial