Change the no-answer diversion timer from your phone’s dialler. Use the instructions for the provider of that SIM. This changes the wait before voicemail, not the ringtone sound or its volume.
Codes for calls left unanswered
Telstra
**61*101**30#
- 30 seconds. Telstra lists 15, 20, 25 or 30 seconds. Press Call.
Optus
**61*321**30#
- 30 seconds. Optus lists five-second increments up to 30. Press Call.
Vodafone Australia
**61*+61414121121*20#
- 20-second example from its device guide. Replace 20 with the desired seconds in a multiple of five, then press Call.
Copy the asterisks and # exactly. The Vodafone example is the Australian provider’s published syntax; codes from Vodafone in another country may differ. For a reseller, use that reseller’s instructions rather than assuming its host-network code applies.
iPhone still answers after 15 seconds?
On Telstra, Apple Live Voicemail can pick up after 15 seconds. Telstra says to turn it off under Settings → Apps → Phone → Live Voicemail before using a longer MessageBank ring time.
Check the change once
Wait for the phone’s confirmation, then call it from another phone while it is idle. Leave the call unanswered. Measure the time to voicemail rather than counting audible rings, whose rhythm can vary.
If the phone goes straight to voicemail, the no-answer timer may not be the issue. Check whether the phone receives calls at all before entering more codes. Rejecting a call also tests a different diversion condition.
If the network rejects the code, save the exact error and ask your provider to set the no-answer timer. Avoid experimenting with “cancel all diversions” codes: you may have other forwarding settings you want to keep.
Sources and review notes
Checked 10 September 2026 against the sources below. This is documentation-based guidance; we did not access a customer account or test these instructions on a handset.
Official sources
Telstra: mobile voicemail101, activation, greetings, ring time, remote access and Apple Live Voicemail.www.telstra.com.au
Optus: change the ring time before diversionVoicemail ring timer **61*321**XX#, five-second increments to 30 seconds.www.optus.com.auVodafone Australia: divert unanswered callsiPhone iOS 18 guide: **61*+61414121121*20#, replace 20 with seconds divisible by five.devices.vodafone.com.au
Michel Elijah covers technology, streaming and online security for Tech X Telco. He writes practical how-to guides on everything from email troubleshooting to spotting the latest scams doing the rounds in Australia, with a focus on clear steps anyone can follow.
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