How to Set Up Call Forwarding on Telstra, Optus and More (2026)
To forward all calls on Telstra, dial **21*number# from your mobile and press call; to cancel, dial ##21#. Those two codes are the core of Telstra call forwarding, and because Australian mobiles run on the GSM standard, the same codes work on Optus, Amaysim, and most other carriers. If you only want to divert the calls you miss (rather than every call), use the conditional codes instead: **61*number# for unanswered calls, **67*number# when you are on another line, and **62*number# when your phone is off. This guide lists the exact codes for each situation, the Telstra call forward to mobile and Optus specifics, how to divert a landline to a mobile, and how to point those diverted calls at an AI receptionist so nothing lands in voicemail.
Call forwarding is a network feature your carrier already provides, so there is no app to install and no equipment to buy. You dial a short code once, your carrier stores the setting on the network, and it stays active until you cancel it. The codes below are standard GSM Man-Machine Interface (MMI) codes; they are the same ones Telstra and Optus publish, but plans and prepaid services vary, so confirm with your carrier if a code does not return a confirmation message. The prefix tells the network what to do: ** sets a new divert, * reactivates a stored one, # turns a divert off, ## erases it, and *# checks the status. Mobile diverts use the double-asterisk form (**21*number#); fixed landlines use the single-asterisk carrier-specific codes covered later.
Call Forwarding Codes at a Glance
Every Australian carrier uses the same four call forwarding types, each with its own code family. Replace number with the destination in full national format (mobile with the leading 04, landlines with the area code, no spaces).
| What you want | Type | Turn on | Cancel | Check status |
|---|---|---|---|---|
| Forward every call | Unconditional (all calls) | **21*number# | ##21# | *#21# |
| Forward unanswered calls | No reply | **61*number# | ##61# | *#61# |
| Forward when you are busy | On busy | **67*number# | ##67# | *#67# |
| Forward when phone is off/no signal | Not reachable | **62*number# | ##62# | *#62# |
| Cancel all diverts at once | All | ##002# | - | - |
A few things to know before you dial. Unconditional forwarding (**21*) means your phone never rings, so use it only when you are away and want everything to go elsewhere. The three conditional codes (**61*, **67*, **62*) ring your phone first and only divert the calls you cannot take, which is what most businesses want. You can set all three conditional codes to the same destination number, and dialling ##002# clears every forwarding rule in one step if you lose track of what is active.
To add a ring delay before an unanswered call diverts, append the seconds to the no-reply code: **61*number**20# waits 20 seconds before forwarding. Valid values are 5, 10, 15, 20, 25, and 30 seconds.
How to Forward Calls on Telstra
On Telstra, **21*number# forwards all calls and ##21# cancels it, while **61*number# diverts only the calls you do not answer. For a Telstra call forward to mobile, use your mobile number as the destination in full national format, starting with 04 and no spaces, for example **21*0412345678# to send every call to that mobile. Telstra applies these standard codes across its mobile plans, both post-paid and most business accounts. Dial the code, wait for the on-screen confirmation ("Setting activation was successful" or similar), and forwarding is live.
For Telstra mobile call forwarding, the codes most owners use are:
- Forward all calls:
**21*number#to activate,##21#to cancel,*#21#to check. - Forward missed (unanswered) calls:
**61*number#, with an optional delay like**61*number**15#. - Forward when busy:
**67*number#. - Forward when unreachable:
**62*number#.
For a Telstra landline, the dial codes differ from the mobile ones above because a fixed line uses a single asterisk. Telstra home and business fixed lines use *21number# to divert all calls and #21# to cancel, *61number# to forward calls you do not answer, and *24number# when the line is busy (note that busy is 24 on a Telstra fixed line, not the 67 used on mobiles). If you are diverting a landline to a mobile in Australia, the all-calls divert is the simplest option; for missed-call-only routing, a mobile number is still easier to work with.
How to Set Up Call Forwarding on Optus
Optus call forwarding uses the same GSM codes as Telstra: **21*number# forwards all calls, ##21# cancels, and **61*number# forwards only unanswered calls. Because the code family is shared across the GSM standard, if you have switched from Telstra to Optus you do not need to relearn anything. Dial the code from the Optus mobile you want to divert and wait for the confirmation message.
The Optus set:
- Forward all calls:
**21*number#on,##21#off,*#21#to check. - Forward unanswered calls:
**61*number#(add**seconds#for a ring delay). - Forward on busy:
**67*number#. - Forward when switched off:
**62*number#.
Optus supports adjustable ring delays on the no-reply code the same way Telstra does. If a code does not activate, the usual cause is a prepaid plan that restricts forwarding or a mistyped number, so check with *#61# and re-enter the destination in full.
Amaysim and Other Carriers (MVNOs)
Amaysim runs on the Optus network, so where call forwarding is supported it uses the same codes: **21*number# to forward all calls and **61*number# for missed calls. The same is true of other MVNOs (smaller carriers that resell Telstra or Optus coverage). Because they ride on the two big networks, the GSM code families are identical.
The catch is that some prepaid and MVNO plans limit or disable call forwarding, especially conditional forwarding. If **21* or **61* does not return a confirmation on Amaysim or another MVNO, the feature may not be enabled on your plan. What to do: dial the status code (*#21# or *#61#) to see the current setting, and if nothing is active, contact the carrier to confirm forwarding is included before you rely on it. Post-paid plans on Telstra and Optus almost always support the full set; budget prepaid plans are the ones to verify. You can see the carrier-by-carrier detail for Telstra, Optus, and Vodafone in our step-by-step call forwarding setup for Australia.
How to Divert a Landline to a Mobile in Australia
To divert a Telstra landline to a mobile in Australia, dial *21number# from the landline handset to forward all calls to your mobile, and #21# to cancel. Use the mobile number in full, starting with 04 and no spaces. On a Telstra fixed line you can also divert only the calls you miss with *61number# (no answer) or *24number# (busy). An Optus home or fixed line uses a different code, *78number (include the area code and wait for two beeps), cancelled with #78.
The landline divert codes differ from the mobile GSM codes above: a Telstra landline uses a single-asterisk *21number#, not the double **21*number# used on mobiles. Once the divert is live, every call to the landline rings straight through to your mobile, or on to whatever you point that mobile at next. Many owners chain the two: divert the landline to a mobile, then set the mobile's conditional codes (**61* for unanswered, **67* for busy) to hand the calls you miss to an AI receptionist, so a fixed business line still gets a real answer when nobody picks up.
How to Divert Missed Calls to an AI Receptionist
The most useful setup for a small business is not forwarding every call; it is forwarding only the ones you miss, so a real answer replaces voicemail. That is conditional call forwarding: your phone rings first, and if you are on a job, driving, or already on another call, the unanswered (**61*) and busy (**67*) diverts hand the call to a backup instead of dropping it into a mailbox. Point that backup at an AI receptionist and every missed call gets a natural conversation, lead qualification, and an appointment booked, rather than a message you return hours later.
This is exactly how Trillet's AI receptionist is designed to work. It sits behind your existing number as a backup: calls ring you first, and the AI only picks up the missed, declined, and busy calls. Setup takes about five minutes, runs over call forwarding with no new hardware, SIM, or number, and costs $49 per month with 150 minutes included, then $0.20 per minute (as of August 2026), with a 28-day money-back guarantee. After each call you get an email summary of what the caller wanted.
To wire it up, get the forwarding number from your AI service and set the conditional codes to point at it: **61*aiNumber**20# to divert after 20 seconds of ringing, and **67*aiNumber# so calls that arrive while you are on the line divert too. Leave **21* alone so your phone keeps ringing normally. Test it by calling your own number from another phone and letting it ring past the delay; the AI should answer with your greeting. The mechanics, VIP allowlists, and what happens during an outage are covered in our guide to conditional call forwarding that keeps your number and adds an AI backup.
Frequently Asked Questions
What is the Telstra call forwarding code?
To forward all calls on Telstra, dial **21*number# and press call; to cancel it, dial ##21#. To forward only the calls you miss, use **61*number# for unanswered calls, **67*number# when you are busy, and **62*number# when your phone is off. Dial *#21# to check whether all-call forwarding is currently active.
How do I set up a Telstra call forward to my mobile?
Dial **21*number# from the Telstra phone you want to divert, using your mobile number in full national format (starting 04, no spaces), then press call and wait for the confirmation message. That forwards every call to your mobile. Use **61*number# instead if you only want the calls you miss to divert, and ##21# to cancel.
How do I turn off call forwarding?
Dial the cancel code for the type you turned on: ##21# for all-call forwarding, ##61# for unanswered, ##67# for busy, and ##62# for unreachable. If you are not sure what is active, ##002# clears every forwarding rule at once. These work the same on Telstra, Optus, and most other Australian carriers.
Does Amaysim support call forwarding?
Amaysim runs on the Optus network, so where forwarding is enabled it uses the same codes, such as **21*number# to forward all calls. Some prepaid and MVNO plans restrict conditional forwarding, so dial *#61# to check the status, and if nothing activates, contact Amaysim to confirm the feature is included on your plan.
How do I divert my landline to my mobile in Australia?
For a Telstra landline, dial *21number# to divert all calls to your mobile and #21# to cancel, or *61number# to divert only the calls you do not answer. A Telstra fixed line uses a single asterisk, unlike the double-asterisk **21*number# on mobiles. An Optus fixed line uses *78number instead (include the area code, wait for two beeps).
Do forwarded calls cost extra?
The forwarding feature itself is free on most Australian mobile plans, but a forwarded call counts as an outbound call from your number to the destination, so it uses your plan minutes. Unlimited-call plans absorb this at no extra cost; limited-minute and some prepaid plans may charge for it, so check your inclusions before relying on forwarding.
Updated August 2026: added a dedicated section and FAQ for a Telstra call forward to mobile, a step-by-step guide to diverting a landline to a mobile in Australia, and a GSM-prefix explainer. Corrected the fixed-line codes to the single-asterisk carrier-specific form (Telstra *21number# / *61number# / *24number#, Optus *78number) to distinguish them from the double-asterisk mobile codes.
