Call forwarding guide: every situation covered

Call forwarding is the single step that connects your existing business number to a new destination — an AI receptionist, a mobile, a cloud line, or an answering service. It takes under five minutes on most carriers, but the wrong setup can send callers to voicemail, create dead air, or break your after-hours coverage entirely.

This guide covers every common situation: Telstra, Optus, and Vodafone mobile; Australian landlines; VoIP and cloud phone systems; on-premises and hosted PBX; toll-free 13/1300 numbers; and what to do when your provider does not support forwarding at all. If you are forwarding to an AI receptionist, pair this with After-hours call handling for Australian SMEs and Peak period phone calls: triage without burnout for the call flows once the call arrives.

TL;DR

• Unconditional forwarding sends every call straight to the destination. Your phone never rings. Use this when you want all calls answered by an AI receptionist or cloud system.
• Conditional forwarding sends calls only when busy, unanswered, or unreachable. Use this for overflow or after-hours only.
• Time-based / rule-based forwarding is available on most VoIP and PBX systems. Use it to forward after 6pm, on weekends, or by caller group.
• Setup varies by carrier and line type. Mobile uses dial codes; landlines, VoIP, and PBX use an online portal or provider support.
• If your provider does not support forwarding, you can port the number or run a parallel number during a transition.
• Always disable voicemail on the original line before going live, and test with a real call.

A quick scenario

You run a physiotherapy clinic in Brisbane. Your main number is a Telstra mobile. You have just set up an AI receptionist to handle bookings and after-hours enquiries. The AI provider gives you a destination number: +61 2 1234 5678.

You need to decide: should every call go to the AI (unconditional), or should the phone ring first and only forward when you miss it (conditional)? And how do you stop your old Telstra voicemail from intercepting the call before the AI picks up?

That is what this guide solves.

Which type of forwarding do you need?

Unconditional (forward all calls)

Every call to your number is sent straight to the destination. The original line does not ring.

When to use it

• You want your main business number answered by an AI receptionist or cloud system full-time.
• You have moved to a new provider but kept the old number and want all traffic routed to the new line.
• You use one number for marketing and want a single, consistent destination for every call.

Conditional (forward when busy / no answer / unreachable)

Calls forward only when your line is busy, you do not answer within a set number of rings, or the line is unreachable (phone off, no signal). Otherwise the original line rings as usual.

When to use it

• You want the office phone to ring first; only overflow or missed calls go to the AI or backup number.
• You want after-hours calls to go to a receptionist, but during business hours you answer yourself.

Time-based or rule-based forwarding

Some VoIP and PBX systems let you forward by time of day, day of week, or caller group. This is configured in the provider's portal or PBX admin — not with handset codes.

When to use it

• You want calls to go to the AI after 6pm and on weekends, but ring the office during business hours.
• You want different destinations for different departments or call queues.

Australian mobile forwarding codes — quick reference

These GSM codes work on Telstra, Optus, and Vodafone. Replace [number] with the destination in E.164 format (e.g. 61412345678). Tap Send or Call after dialling the code.

Important notes on codes

• Destination must be in E.164 — country code + number, no spaces, no leading zero. Australian mobile example: 61412345678. Sydney landline example: 61212345678.
• Some business plans or MVNOs (amaysim, Boost, Woolworths Mobile, etc.) may use different codes or restrict forwarding. Always confirm with your carrier or check the carrier's app.
• You can also manage forwarding through the Telstra 24x7 app, My Optus app, or Vodafone app if you prefer not to use dial codes.

Setup by carrier and line type

Telstra mobile

1. Unconditional: Dial *21*[full number]#, tap Send. To cancel: #21#.
2. No answer: *61*[full number]#. Cancel: #61#.
3. Busy: *67*[full number]#. Cancel: #67#.
4. Unreachable: *62*[full number]#. Cancel: #62#.

You can also use the Telstra 24x7 app or My Account portal. Business plans may have different menus; confirm in the app or call 132 200.

Disabling Telstra voicemail: Dial 1500 and follow the prompts to turn off voicemail, or call 101 from your handset and navigate to voicemail settings. If voicemail stays active, it can intercept calls before the forward completes.

Optus mobile

1. Unconditional: *21*[full number]#, tap Send. Cancel: #21#.
2. No answer: *61*[full number]#. Cancel: #61#.
3. Busy: *67*[full number]#. Cancel: #67#.

Landline-style services on Optus (e.g. home phone) are configured via My Optus or by calling support.

Disabling Optus voicemail: Dial 321 from your handset and follow the prompts, or use the My Optus app under call settings.

Vodafone mobile

1. Unconditional: *21*[destination number]#. Cancel: #21#.
2. No answer / busy / unreachable: Same pattern with *61*, *67*, *62*.

Disabling Vodafone voicemail: Dial 121 and follow the prompts, or manage in the Vodafone app.

Other Australian mobile carriers (MVNOs)

amaysim, Boost, Woolworths Mobile, Aldi Mobile, and others generally use the same GSM codes. Some MVNOs restrict forwarding or charge for it. Check your carrier's help centre or app before activating.

Landline (Telstra, Optus, NBN-based)

Landlines do not use handset dial codes. Forwarding is configured through your provider:

• Telstra: Log in to My Account or call 132 200. Request "call divert" for your service. You can set unconditional or conditional divert.
• Optus: Use My Optus or call support. Request call forwarding/divert.
• NBN / other providers (Aussie Broadband, TPG, iiNet, Internode): Use the provider's portal or call support. Some NBN voice services have limited forwarding options.

You will need the destination number in E.164 format.

VoIP and cloud phone systems

Examples: Zoom Phone, Microsoft Teams Phone, 8x8, RingCentral, Dialpad, GoTo Connect, 3CX, and many others.

Forwarding is almost always configured in the admin portal or user settings, not on a handset.

What to look for in your portal:

• "Call forwarding", "call divert", "simultaneous ring", or "failover"
• Unconditional forward, no-answer forward, and busy forward (often configurable to different numbers)
• Time-based rules (e.g. after 6pm forward to an AI receptionist number)
• Ring timeout setting (how many seconds before "no answer" triggers)

Disable or shorten the voicemail timeout on the VoIP line so the AI or cloud system handles missed calls rather than your old voicemail.

Business PBX (on-premises or hosted)

• Hosted PBX: Same approach as VoIP — use the provider's web portal to set forward rules and destination numbers.
• On-premises PBX (legacy PABX, Avaya, Panasonic, NEC, etc.): Forwarding is configured on the system itself, usually via the admin handset or installer. Some older systems cannot forward to an external number. In that case, you may need a SIP trunk or number port to a cloud provider that supports forwarding.

If you are unsure, ask your PBX vendor: "Can we set an external forward destination for inbound calls on this system?"

Toll-free (13 / 1300 numbers)

13 and 1300 numbers in Australia are provided by carriers or specialist number managers. Forwarding is not configured on a handset — it is routing at the carrier level.

• You set the destination for the 13/1300 number to point to your AI receptionist number or another landline/mobile.
• Contact your 13/1300 provider or account manager to set or change the destination.
• Some providers offer time-of-day routing, geographic routing, or overflow rules in their portal.

Forwarding to an AI receptionist (step by step)

When you forward to an AI receptionist (e.g. Valory), you will receive a destination number in E.164 format. Use that number as the forward target.

Recommended setup

1. Choose your forwarding type. Unconditional if the AI should answer every call. Conditional (no answer / busy) if you want the office to ring first and only overflow to the AI. Time-based if the AI handles after-hours only.

2. Disable voicemail on the original line. This is the most common mistake. If voicemail is still active, callers can hit your old voicemail before the forward completes — especially with conditional forwarding where the timeout is short. Turn off voicemail or set the timeout to the maximum so the forward takes precedence.

3. Activate forwarding using the appropriate method for your carrier and line type (dial codes, app, portal, or provider support).

4. Test immediately. Call your business number from another phone. Confirm the AI answers, says the correct greeting, captures details, and performs any configured actions (transfer, SMS, booking link). If something is wrong, cancel forwarding (#21# on mobile) and fix before relying on it.

5. Tell your team. Staff should know calls are being forwarded, what the AI handles, and how to check call summaries or follow up on captured leads.

If you only want the AI to handle after-hours or overflow, use conditional forwarding (no answer / busy) to the AI number, or use time-based rules in your VoIP/PBX so that outside business hours calls route to the AI.

For the call flows and scripts once the AI is answering, see:

• After-hours call handling for Australian SMEs
• Peak period phone calls: triage without burnout
• AI phone agent vs answering service vs voicemail

When you cannot forward

Some providers or plans do not support call forwarding, or only support it to certain number types. Here are your options.

1. Number porting

Port your existing number to a provider that supports forwarding (e.g. a VoIP or cloud telephony provider). Once ported, set the destination to your AI or cloud line.

• Porting typically takes 1–5 business days in Australia.
• There may be a brief outage (minutes to hours) during the cutover.
• Plan the port for a low-traffic period and notify customers if needed.

2. Parallel number

Get a new number for the AI receptionist and use it as your published inbound number (website, Google Business Profile, ads, directories). Keep the old number during a transition period and tell callers to use the new number.

This avoids porting risk but means updating your marketing materials.

3. Keep the old number for outbound only

Use the existing number for outbound calls and caller ID. Use the new AI number as the main published number for inbound. Not ideal if you want one number for everything, but workable during a transition.

Not sure if your provider supports forwarding? Call them and ask: "Can I set up call divert from my number to another Australian number (mobile or landline)?" If they say no, ask about porting options.

Troubleshooting common issues

Calls still go to voicemail

Voicemail on the original line is intercepting calls before the forward triggers. Disable voicemail or extend the timeout. On Telstra, dial 1500; on Optus, dial 321; on Vodafone, dial 121.

Forwarding activates but the destination does not answer

Check the destination number format. It must be E.164 (e.g. 61412345678, not 0412 345 678). If the format is correct, call the destination number directly to confirm it is active and answering.

Caller hears ringing but nobody picks up

This usually means conditional forwarding is set but the timeout is too short or too long. Adjust the ring timeout in your carrier's app or portal. For no-answer forwarding, 15–20 seconds (4–5 rings) is a reasonable default.

Forwarding works but caller ID shows the wrong number

Some carriers pass through the original caller's number; others show the forwarding number. This depends on your carrier and the destination provider. If caller ID matters for your workflow, confirm with both providers how CLI (Calling Line Identification) is handled on forwarded calls.

Forwarding code returns an error or does not activate

Your plan may not support forwarding, or the code may be different for your carrier. Try the carrier's app or portal instead. If that fails, call support and ask them to enable call divert on your service.

Calls forward but the AI greeting is delayed or cut off

This can happen when the forwarding chain is long (e.g. mobile to landline to VoIP to AI). Each hop adds latency. Reduce hops where possible — forward directly from the original number to the AI destination.

Checklist before you go live

• Confirm your carrier and line type (mobile, landline, VoIP, PBX, toll-free)
• Get the destination number in E.164 format (e.g. 61412345678)
• Choose forwarding type: unconditional, conditional, or time-based
• Disable voicemail on the original line (or set timeout to maximum)
• Activate forwarding using codes, app, or portal
• Call your own number from another phone and confirm the destination answers
• Test the full flow: greeting, lead capture, transfers, SMS, booking links
• Confirm caller ID behaviour on forwarded calls
• Tell your team what is forwarded, what the AI handles, and where to find call summaries
• Set a reminder to review call outcomes after the first 48 hours

FAQ

What is unconditional call forwarding?

Unconditional forwarding sends every call to your number straight to another number. Your phone does not ring; the destination number rings (or is answered by an AI or receptionist). Activate on Australian mobile with *21*[number]#.

What is conditional call forwarding?

Conditional forwarding sends calls to another number only when your line is busy, you do not answer within a set number of rings, or the line is unreachable (phone off, no signal). Otherwise your phone rings as usual.

Do call forwarding codes work on all Australian mobiles?

The common GSM codes (*21#, *61#, *67#, *62#) work on Telstra, Optus, and Vodafone. Most MVNOs support them too, but some restrict or charge for forwarding. Always confirm with your carrier.

Can I forward a landline to a mobile or VoIP number?

Yes, if your landline provider supports call divert. Configuration is usually via the provider's portal or customer support, not dial codes. Give them the destination number in E.164 format.

Can I forward a 13 or 1300 number?

Yes. Contact your 13/1300 number provider or account manager. They set the destination at the carrier level. Some providers also offer time-of-day and overflow routing.

Why should I turn off voicemail when forwarding?

If voicemail is active, callers can hit your old voicemail before the forward completes — especially with conditional forwarding where the ring timeout is short. Disabling voicemail ensures the AI or destination handles every call.

My provider says they do not support forwarding. What can I do?

You can port your number to a provider that supports forwarding, or use a new number for the AI receptionist and phase the old number out. Some businesses run both during a transition. See the "When you cannot forward" section above.

How do I cancel call forwarding?

On mobile: #21# (unconditional), #61# (no answer), #67# (busy), #62# (unreachable), or ##002# to cancel all. On landline or VoIP, use the provider's portal or support.

What number format should I use for the destination?

Use E.164: country code + number with no spaces or leading zeros. Australian mobile: 61412345678. Australian landline (Sydney): 61212345678.

Does call forwarding cost extra?

It depends on your carrier and plan. Some plans include forwarding at no extra charge; others treat forwarded calls as an outgoing call from your number to the destination. Check with your carrier for forwarding charges on your specific plan.

Will the caller know their call has been forwarded?

Usually not. The caller experience is seamless — they dial your number and hear the destination answer. Some carriers play a brief tone or delay, but most forward transparently.

Can I forward to an international number?

Some carriers support international forwarding, but charges apply and not all plans allow it. If your AI receptionist or destination is on an Australian number, this is not an issue.

Next step

If you want help mapping your number type and setting up forwarding to an AI receptionist, we can walk through your carrier, line type, and a safe rollout in under fifteen minutes.

Book a walkthrough or browse more guides in our articles library.