How to Set Up Call Forwarding in Australia

TL;DR

To set up no-answer call forwarding in Australia, use your carrier's published code or your phone's call-forwarding settings, enter the destination number, then test from a second phone. Optus documents **61*number**20# for a 20-second delay; Telstra's current mobile guide uses **61*number*11# to activate voice-call diversion, with a separate ring-time setting. Conditional forwarding lets your phone ring first and sends unanswered calls to a backup, whether that is a colleague, an answering service, or an AI receptionist like Trillet. The setup itself can take a few minutes, but the exact code, timer and charges depend on your carrier and plan. This guide separates Telstra, Optus, Vodafone and fixed-line instructions so you can check your service before relying on it.

The mobile service codes share familiar 21 (all calls), 61 (no answer), 67 (busy), and 62 (unreachable) categories, but their activation syntax is not identical in every carrier guide. ## commonly cancels a divert and *# checks status; fixed lines use separate carrier-specific procedures. Use the published instructions for your service, not a code copied from a different network.

What You Need Before Starting

Call forwarding works with most Australian mobile and landline services, but there are specific requirements and restrictions you need to know about.

  • A mobile or fixed-line plan that permits diversion to your chosen destination. Prepaid does not automatically rule it out: Optus publishes prepaid diversion charges, while Kogan offers forwarding through a paid Premier Access Bolt-On and amaysim publishes a forwarding surcharge. Check your own carrier's current plan terms before setup.
  • The phone number you want to forward calls to. This could be another mobile, a landline, a virtual receptionist service, or an AI answering service.
  • 2 minutes to dial the forwarding code and test it. No special equipment or technical skills required.

The most common use cases are forwarding to answering services, business partners who cover your calls, or second phones. Some Australian businesses forward to AI answering services like Trillet ($49/month, 150 minutes included) to handle qualification and appointment booking automatically.

Understanding Call Forwarding Types

Australian mobile carriers commonly offer four forwarding conditions. Most businesses want one or more conditional rules, which redirect calls only in the circumstances selected.

Unconditional forwarding

Every call goes directly to the forwarding number. Your phone never rings. This is useful for planned coverage; the mobile service category is 21, but confirm your carrier's activation syntax before dialling.

Conditional forwarding (busy/unanswered)

Your phone rings first under a no-answer rule; a separate busy rule can redirect calls when your line is engaged. This is backup, not replacement. Mobile service categories are 61 for no answer and 67 for busy. Optus documents **61*number**seconds# for no-answer timing; Telstra documents **61*number*11# for activation and 15–30-second timing in five-second increments. Set and test each condition separately.

Conditional forwarding (unreachable only)

Forwards only when your phone is off or out of coverage. It is less common for business use. The mobile service category is 62; confirm the activation format for your carrier and handset.

Setting Up Call Forwarding by Carrier

The forwarding conditions have similar service codes across mobile networks, but the published dial strings and timer formats differ. Fixed landlines have their own instructions too. For another carrier-oriented walkthrough, see our reference on Telstra and Optus call-forwarding codes, then check the carrier's current support page before changing a live business line. If your number is with a US carrier, our guide on how to forward calls on AT&T, Verizon and T-Mobile covers those codes instead.

Telstra mobile

  • Telstra's current business-mobile guide gives **21*number*11# for all calls, **61*number*11# for no answer, **67*number*11# for busy, and **62*number*11# for unreachable. Include the destination's area code when relevant.
  • Check a condition with *#61# (or replace 61 with 21, 67, or 62); cancel it with ##61# (or the corresponding code). Telstra also offers SMS-to-144 control for all-call forwarding.
  • Telstra lists 15, 20, 25 and 30 seconds for no-answer delay, but its published **61*101**seconds# timer example specifically targets MessageBank (101). Do not substitute an AI number into that example without Telstra's confirmation. For a third-party destination, use the documented activation string above and ask Telstra how to change its timer on your service.

Optus mobile

  • Optus documents **61*number**20# for a 20-second no-answer delay. It lists 5–30 seconds in five-second increments; other diversion conditions can also be managed through handset settings or the My Optus app.
  • Optus charges the forwarded leg according to your plan; its published prepaid rate is 10 cents a minute for domestic diversion. Check the current diversion-cost schedule before assuming forwarding is free.

Vodafone mobile

  • Vodafone's device guide describes diversion to voicemail for the 21, 61, 62 and 67 conditions. It does not establish the correct dial string for forwarding to an external AI answering number. Check Vodafone's instructions for your handset and plan or ask support to confirm the destination and timer settings before changing a business line.

Telstra landline (fixed line)

  • Forward all calls: *21number#, cancel with #21#
  • Forward unanswered calls: *61number#
  • Forward when busy: *24number# (busy is 24 on a Telstra fixed line, not the 67 used on mobiles)

Optus landline (fixed line)

  • Optus's home/office support confirms #78 removes an active network diversion. Activation varies by fixed-line product, so check your specific Optus home or office service instructions rather than assuming a mobile code or a universal *78number format.

Important notes on phone number formatting

  • For a landline destination, include its area code, such as 02 for a Sydney number; Telstra and Optus both call this out in their mobile instructions.
  • For a mobile destination, include the full mobile number, including its 04 prefix.
  • Follow your carrier's complete activation syntax above. The number examples are destinations, not universal dial strings; the separators and optional timer differ by network and service.

An activation confirmation is useful, but it is not proof that callers will reach the destination. Test from another phone; if the code fails, check handset settings and carrier support before assuming your plan does not support diversion.

Testing Your Call Forwarding Setup

Always test before relying on call forwarding for real business calls. Use a different phone (a friend's mobile, another business line, or your home phone) to verify it works.

Test scenarios to verify:

  • Your phone rings first (conditional forwarding shouldn't bypass you)
  • Unanswered calls forward after the ring time you set
  • Calls forward when you decline them manually, if your carrier and handset treat a declined call as busy
  • Busy signal triggers forwarding if you're on another call

The forwarding number should receive the call within seconds of your phone stopping ringing. If there's a long delay or the call drops, the forwarding number might be unreachable or experiencing technical issues.

Some businesses test by deliberately missing a few calls during quiet periods. Real-world testing catches issues that a single controlled test might miss, like network delays or specific caller ID problems.

Common Use Cases for Call Forwarding

Australian businesses use call forwarding for different reasons. The setup is identical regardless of what you're forwarding to.

Forwarding to answering services

Human answering services like Ruby or Smith.ai's human-receptionist offering can cover calls when you are busy. AI answering services like Trillet (US$49/month, 150 minutes included, then $0.20/minute as of September 2026) can also qualify leads and book appointments when connected to a supported calendar. Either type can receive a conditional divert where your carrier supports it, so your phone can ring first.

Forwarding between business partners

Sole traders often forward to a business partner who covers calls during court appearances, site visits, or focused work. Therapists forward to practice managers. Tradespeople forward to apprentices or office staff.

Forwarding to second phones

Some business owners maintain separate work and personal mobiles. Conditional forwarding lets your business line roll to your personal phone when you're away from the office, without giving clients your personal number.

Forwarding for after-hours coverage

Unconditional forwarding works for planned absences. Activate the carrier-specific all-call (21) rule before leaving, test that every call reaches your coverage, and cancel the rule on return. Forwarding charges depend on the carrier and plan, so check the diverted-leg cost before activating it.

Troubleshooting Call Forwarding Issues

Call forwarding didn't activate

Try the status code *#61# or inspect your handset's Call Forwarding settings. If the destination is still your voicemail number, the AI or answering service will not receive no-answer calls. Common causes include a rejected dial string, a conflicting voicemail rule, an ineligible destination, or insufficient prepaid credit for a charged diverted leg.

Prepaid plans blocking forwarding

Do not assume all prepaid plans block forwarding. Optus publishes prepaid diversion rates; Kogan sells a forwarding-capable bolt-on; amaysim publishes call-forwarding charges. If your code fails, check your exact plan, any required credit or add-on, and the provider's permitted destination types before changing plans.

Forwarded calls going to voicemail

If calls forward but immediately hit voicemail on the forwarding number, that number is either turned off, out of coverage, or has its own forwarding active (creating a loop). For answering services, verify the number is correct and the service is active. For second phones, check coverage and ensure that phone isn't forwarding elsewhere.

Forwarding costs adding up

Forwarding can be included, billed as a call, or charged per minute, depending on the carrier and exact plan. Telstra says forwarding is included in plans with an unlimited call allowance; that is not a promise for every business service. Optus publishes specific diversion charges for some plans, including prepaid. Check your plan's current terms and a test bill before relying on forwarding for high call volumes.

International forwarding blocked

International forwarding eligibility and charges vary by carrier and plan. Optus's public rate page distinguishes postpaid and prepaid rules, so ask your carrier about the exact overseas destination before relying on it. An Australian answering-service destination can avoid an international forwarded leg.

Why Conditional Forwarding Matters for AI Answering Services

AI answering services can be used for all calls or only for overflow; the choice depends on your workflow and forwarding settings. Unconditional forwarding sends every call away before your phone rings, while a no-answer rule lets you answer personally when available.

Trillet supports this backup pattern through conditional forwarding: your phone rings first, then the AI handles calls you miss. You can also configure the AI to answer every call when that better suits your business. The conditional forwarding guide explains the backup setup in more detail.

AI can't replace humans when it comes to relationships. A therapist who answers their own phone builds trust differently than one who never does. A lawyer who takes calls during breaks strengthens client relationships. A tradie who picks up between jobs demonstrates availability. These interactions matter.

An AI receptionist can be more useful than voicemail for routine questions and supported bookings, but it still needs accurate business information, a connected calendar, a tested forwarding rule, and a human callback path when it cannot resolve the request. Trillet can cover the calls you cannot take without forcing every caller through the AI.

This is why Trillet positions itself as a copilot, not a replacement. The conditional forwarding setup reinforces this. You stay in control. The AI fills gaps, it doesn't push you out of your own business.

Forwarding your number to Trillet

Trillet's setup shows the forwarding code for your carrier, including Telstra, Optus and Vodafone: dial it, or scan the on-screen code with your phone, then wait for the confirmation tone. On a mobile you choose when calls forward: when you don't answer, when you're busy, when you're unreachable, or all calls, depending on what your carrier supports. Landlines and VoIP lines forward all calls. To stop, dial your carrier's removal code. Trillet has no ring-count setting of its own, so how long your phone rings before an unanswered call forwards is set by your carrier (see the ring-delay question below).

As of September 2026, Trillet's direct AI receptionist costs US$49 per month with 150 minutes included, then $0.20 per extra minute. SMS is charged separately, and your carrier may charge for the forwarded leg; check both before estimating total cost. The receptionist pricing page gives the plan details, while the complete AI receptionist guide covers the broader setup and cost trade-offs.

If you want to test the backup approach, use your carrier's current instructions, place test calls for no-answer and busy conditions, and review the results in Trillet. Its D2C plan has a 28-day money-back guarantee, not a free trial; the guarantee applies to the plan under the public terms, not automatically to carrier, SMS or usage charges.

Frequently Asked Questions

How do I forward my Telstra mobile to another number?

Telstra's current business-mobile instructions give **21*number*11# to forward every voice call and **61*number*11# for no-answer forwarding. Include the full destination number, press call, then test from a second phone. Cancel the all-call rule with ##21#. Optus and Vodafone publish their own syntax, so do not assume a Telstra dial string works unchanged on either network.

How do I divert an Optus landline?

Optus confirms that #78 removes an active home or office network diversion. Activation depends on whether the service is a traditional fixed line, nbn voice, or an office product, so use your plan's Optus instructions or contact support before trying a code. A mobile **21* string is not a safe substitute for fixed-line setup.

How do I turn off call forwarding?

On mobiles, the familiar cancellation codes are ##21# for all calls, ##61# for unanswered, ##67# for busy, and ##62# for unreachable. ##002# may clear all diversions, including voicemail-related settings, so record your original setup first and confirm your carrier's restoration steps. Fixed-line cancellation differs; Optus home/office support confirms #78 for an active network diversion. Forwarding to Trillet stops the same way: dial your carrier's removal code from your own phone, because the diversion lives with your carrier, then call your number to check it rings you again.

Do the codes differ between Telstra, Optus, and Vodafone?

The condition numbers 21, 61, 67, and 62 are common on Australian mobile services, but Telstra, Optus, and Vodafone publish different dial-string examples, especially for voice-call activation and ring delay. Telstra fixed-line and Optus home/office services also use different procedures. Follow the guide for your exact carrier, handset, and plan.

How do I add a ring delay before calls forward?

On Optus mobile, **61*number**20# is the published example for a 20-second delay to another number, with choices from 5 to 30 seconds in five-second steps. Telstra documents 15, 20, 25 or 30 seconds, but its published timer example uses its MessageBank number rather than an arbitrary AI destination. Vodafone's cited guide covers voicemail diversion only. Confirm the external-destination timer format with your own provider, then test the actual ring duration. Trillet itself has no ring-count setting, so the delay before an unanswered call reaches the AI is whatever your carrier's timer allows.

Updated September 2026: separated Telstra, Optus and Vodafone mobile instructions after checking each carrier's published syntax, corrected prepaid availability and forwarding-cost claims, qualified fixed-line activation, and clarified that Trillet's 28-day plan guarantee is not a free trial or a promise to refund ancillary charges; added how forwarding to Trillet works (the carrier code to dial or scan, the forwarding choices by line type, the removal code and the carrier-set ring delay) and a pointer for US carriers.

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