Telstra Business Phone Retirements Explained: What's Actually Shutting Down

Telstra is retiring specific legacy business voice products, not shutting down SIP or VoIP as a whole. If you use Telstra Business SIP, Telstra DOT, Telstra Calling for Microsoft 365, or a Telstra-hosted 1300/1800 number, one or more of these retirements may apply to you, each with its own date. If your SIP or VoIP service comes from a different carrier, such as Vocus or Commander, a Telstra product retirement does not automatically affect you, even if some calls interconnect with Telstra's network along the way. This guide sets out exactly what is retiring, when, who needs to act, and how to check what you actually have.

Prices are in AUD including GST.

What Is Actually Happening (In Plain Language)

Telstra has been retiring a set of older business voice products rather than continuing to invest in them, encouraging affected customers toward its newer cloud-based Telstra Adaptive Collaboration platform or an alternative provider. This applies to specific named products, not to SIP or VoIP as a category, and not to Telstra's network as a whole.

This is not unusual in the Australian telco market. The broader PSTN copper network was switched off in 2025, and carriers have been retiring legacy voice platforms since. What matters for your business is which specific Telstra product you are on, since each has its own retirement date, and some Telstra voice products, including Telstra SIP Connect, are not being retired at all.

The Retirement Timeline: What's Actually Ending, and When

The dates below apply to specific named Telstra products. Do not treat any single date as a blanket deadline for "Telstra VoIP" as a whole, check which row actually matches the product on your bill.

Telstra DOT and T-Biz Voice on the nbn: end of sale 30 September 2025, end of life 30 August 2027. These are two of Telstra's own hosted small business phone products. See our dedicated guides for Telstra DOT and T-Biz Voice for the full detail.

Telstra Calling for Microsoft 365: stopped taking new customers 1 November 2024, stop-sell for existing-customer additions 30 August 2026, fully withdrawn 30 November 2026. This is the product that connects Microsoft Teams calling to Telstra's network. You do not need to stop using Teams, only the Telstra calling connection needs replacing.

Telstra Business SIP: stopped taking new customers 30 May 2025. Telstra has not published a full shutdown date for existing customers, who can continue on their current terms "until further notice." Treat this as a signal to plan ahead, not a confirmed deadline. This is a different product from Telstra SIP Connect, which remains actively sold, see "Who is NOT affected" below.

Telstra Wholesale Call Termination Services (CTS) and Wholesale Inbound Numbering (13/1300/1800): these are wholesale, carrier-to-carrier products, not retail products a business signs up for directly. Wholesale CTS stopped taking new wholesale customers from September 2024, with a full exit on 30 September 2026. Wholesale Inbound Numbering stopped taking new connections in November 2024, with a full exit around 24 November 2025.

These dates affect other carriers and providers, including MVNOs and smaller VoIP resellers, that use Telstra's wholesale network to terminate calls or host 1300/1800 numbers. They do not directly affect Telstra's own retail SIP, DOT, or T-Biz Voice customers, and they do not affect customers of other carriers such as Vocus or Commander just because those carriers interconnect with Telstra. See "Using another provider?" below.

Who Is Affected

You are directly affected if your business is a Telstra retail customer on one of these named products:

• Telstra DOT (Digital Office Technology), a hosted small business phone system, end of life 30 August 2027
• T-Biz Voice on the nbn, Telstra's basic hosted business voice service, end of life 30 August 2027
• Telstra Calling for Microsoft 365, Teams calling connectivity via Telstra, withdrawn 30 November 2026
• Telstra Business SIP, stopped selling to new customers 30 May 2025 (existing customers continue for now, no confirmed end date yet)
• A Telstra-hosted 13, 1300 or 1800 number on Telstra's own retail legacy inbound platform, distinct from the Wholesale Inbound Numbering product other carriers use, see the FAQ below on how to tell the difference

• Telstra SIP Connect, Telstra's current SIP trunking product for business and enterprise customers, remains actively sold and supported, it is a different product from the retiring Telstra Business SIP
• SIP or VoIP services from another carrier (Vocus, Commander, or any other provider), even if calls interconnect with Telstra's network or your internet access runs over Telstra or NBN infrastructure, see "Using another provider?" below
• Telstra mobile services, your mobile phone plans, SIM cards, and mobile fleet are completely separate from these retirements
• Telstra NBN broadband, your internet connection is not affected, these retirements are about voice products, not data
• Telstra Adaptive Collaboration, this is Telstra's newer cloud communications platform (based on Microsoft Teams voice and other cloud services). This is not being retired, it is the direction Telstra is pushing affected customers toward
• Telstra phone plans on NBN, if you have a basic home-style line bundled with NBN, check whether it runs over an ATA adapter rather than one of the products listed above

Using Vocus, Commander or Another SIP Provider?

A Telstra product retirement does not normally affect you just because your provider's network happens to interconnect with Telstra, or because some of your access infrastructure is ultimately carried over Telstra or NBN infrastructure. Your SIP service is controlled by your own provider, not by Telstra's retail product lifecycle.

For example, a Vocus or Commander SIP service remains a Vocus or Commander service even where some physical access infrastructure belongs to another carrier, calls terminate on Telstra numbers, your provider interconnects with Telstra to complete calls, or NBN infrastructure is involved somewhere in the path. An upstream network relationship does not automatically make your SIP service subject to a Telstra retail product retirement.

Who Is NOT Affected

A lot of businesses are understandably confused by broad "Telstra VoIP shutdown" headlines. To be clear, the following are not affected by any of the retirements above:

• Telstra mobile services, your mobile phone plans, SIM cards, and mobile fleet are completely separate from the VoIP/SIP shutdown
• Telstra NBN broadband, your internet connection is not affected. The shutdown is about voice products, not data
• Telstra Adaptive Collaboration, this is Telstra's newer cloud communications platform (based on Microsoft Teams voice and other cloud services). This is not being shut down, it is the direction Telstra is pushing customers toward
• Telstra phone plans on NBN, if you have a basic home-style line bundled with NBN, check whether this is an ATA-based service (see below) rather than the SIP products listed above

What Happens to Your Phone Numbers

This is the question most businesses worry about most. The good news: you own your phone numbers, not Telstra. Under the Australian Communications and Media Authority (ACMA) framework, phone numbers, including geographic numbers, 1300 numbers, and 1800 numbers, can be ported to a new provider.

Number porting is the process of transferring your existing phone number from one carrier to another. Your new provider initiates the port on your behalf. For an individual geographic business number, the process generally takes 8 to 15 business days; a complex port may take up to 30 business days. 1300 and 1800 numbers transfer separately through the ACMA Smart Numbers database under a carrier assignment model; as a practical estimate, allow several business days to two weeks for a straightforward transfer and 3 to 4 weeks for complex routing arrangements.

The critical rule: do not cancel your Telstra service before the port completes. If you cancel first, you may lose the number entirely. Your new provider should manage this sequence for you, but confirm it with them explicitly before signing anything.

For a detailed walkthrough of the porting process, see Number Porting in Australia: How It Works for Business.

Your Options: What Can Replace Telstra's Services

The replacement category is broadly called cloud phone system or cloud PBX. These are phone systems that run over the internet rather than traditional phone lines. Here is what that means in practice:

• Your calls travel over your internet connection instead of a dedicated phone line
• The phone system itself lives on a server somewhere else (not in your office), managed by your provider
• You get features you probably do not have now, hold music, auto-attendant (the "press 1 for sales" menu), ring groups, voicemail to email, call recording, softphone apps for mobiles and laptops
• You keep your phone numbers via the porting process described above
• Cost is typically per seat per month, usually in the range of $25 to $60 per user per month including GST depending on the plan

"Cloud PBX" and "cloud phone system" are often used interchangeably. PBX stands for Private Branch Exchange, it is the system that manages calls within your business (extensions, transfers, hold, etc.). A cloud PBX does this from a server your provider manages, rather than a box in your server room.

For an introduction to how these systems work and what to look for, see What Is VoIP? A Plain-Language Guide for Australian Businesses.

If you are ready to move off Telstra and find a replacement, see Best VOIP Phone System for Small Business Australia, a comparison of the cloud phone system options available to Australian businesses right now.

For a full side-by-side comparison of what changes when you move from a traditional Telstra phone line to a cloud-based VOIP system, including cost, features, and what to watch for, see VOIP vs Traditional Phone Australia.

How to Migrate Before the Deadline: Step by Step

Here is the practical sequence most businesses should follow:

Step 1, Confirm exactly which Telstra product you have. Call Telstra Business on 13 2000 or log into your Telstra Business account and check your phone services against the named products above (DOT, T-Biz Voice, Calling for Microsoft 365, Business SIP, or a Telstra-hosted 1300/1800 number). Write down the product name and the phone numbers on each service. If none of these match, and your SIP or VoIP service comes from a different provider, this timeline does not apply to you.

Step 2, Audit your current call flows. How do calls come in to your business right now? Do you have a receptionist, an auto-attendant, a 1300 number, multiple lines, or ring groups? Write down what you have and what you need, this tells you what features your new system must support.

Step 3, Check your internet connection. A cloud phone system runs over your NBN or business internet, and call quality depends on your upload speed and how much traffic is on your connection. As a rule of thumb, each simultaneous call needs about 100 Kbps of reliable upload bandwidth, so a business with 5 staff taking calls at the same time needs at least 500 Kbps of dedicated upload capacity.

Use the VoIP Bandwidth Calculator to check whether your current connection can handle your call volume.

Step 4, Get a cost estimate. The costs vary significantly depending on your team size, the features you need, and whether you need new handsets. Use the VoIP Cost Calculator to get a ballpark figure for your situation before approaching providers.

Step 5, Choose a provider and sign up. Look for Australian-based providers with local support, a clear SLA, and experience with number porting. Your new provider will manage the migration process, including the port of your existing numbers from Telstra.

Step 6, Plan your cutover date. A cutover is when you switch from your old system to the new one. Plan this for a low-traffic period, such as early morning, a late Friday, or a public holiday eve. Your provider should give you a cutover checklist.

See VoIP Cutover Checklist for Australian Businesses for what to prepare.

Step 7, Do not cancel Telstra until the port is confirmed complete. This is the most common mistake. Wait for written confirmation from your new provider that all numbers have ported successfully before cancelling your Telstra account.

For a full migration walkthrough, see How to Migrate Your Business Landline to VoIP in Australia.

How Much Will It Cost

Costs vary by team size and features, but here are realistic ballpark figures including GST:

• 1 to 5 users: $30 to $50 per user per month for a basic plan. Total: $150 to $250/month.
• 6 to 20 users: $25 to $45 per user per month. Total: $150 to $900/month depending on features.
• 20 to 50 users: Pricing typically scales down per seat. Expect $20 to $40 per user per month at this volume.
• Handsets (if needed): Basic SIP desk phones from $90 to $200 each. Mid-range models $200 to $350 each.
• Number porting fees: Usually $0 to $30 per number depending on the provider.
• Setup / installation: Many providers offer self-setup. Managed installation for larger offices typically $500 to $2,000 depending on complexity.

For a personalised cost estimate, use the VoIP Cost Calculator. For a deeper breakdown of what drives costs, see VoIP Costs in Australia: What to Actually Expect.

What Most Businesses Get Wrong

Mistake 1: Treating "September 2026" as your deadline when it may not be. September 2026 is the Telstra Wholesale CTS exit date, a carrier-to-carrier product, not a retail deadline for most small businesses. If you are on Telstra DOT or T-Biz Voice, your real deadline is 30 August 2027.

If you are on Telstra Calling for Microsoft 365, your deadline is 30 November 2026. If you are on Telstra Business SIP, there is no confirmed date yet, check which product you actually have before assuming any specific date applies to you.

Check which product you actually have before assuming a specific date applies, then plan the migration early regardless. Individual local-number ports generally take 8 to 15 business days, complex ports may take up to 30 business days, and provider intake queues fill up as deadlines approach.

Mistake 2: Cancelling Telstra before the port is done. If you cancel your Telstra service before your phone numbers have successfully ported to your new provider, you can lose those numbers permanently. The porting process only works when the number is still active with the losing carrier (Telstra). Always get written confirmation that the port is complete before cancelling anything.

Mistake 3: Not checking the internet connection first. Many businesses assume their existing NBN service is fine and discover during setup that their upload speed is not enough for reliable calls, or that the connection drops during peak hours. Run the bandwidth check before you sign a contract, not after. Your provider should also do this, but do not rely on them being thorough, check it yourself with the Bandwidth Calculator.

Mistake 4: Assuming Telstra will handle the migration for you. Telstra will notify you that your service is ending, but they will not automatically migrate your numbers or set up your new system. You need to choose a new provider and initiate the process yourself.

Telstra's communications will often suggest their own products, like Adaptive Collaboration, but you are free to go to any provider, and you should compare before deciding.

Your Next Steps

• Confirm with Telstra which specific products your business uses (call 13 2000 or check your bill)
• Write down all your business phone numbers and the services they run on
• Audit your call flows, what features do you use, what features do you need?
• Run the Bandwidth Calculator to confirm your internet can handle your call volume
• Use the Cost Calculator to get a ballpark cost for your migration
• Get a provider recommendation matched to your setup
• Book your cutover date with your new provider well before your specific product's retirement date, not a generic "September 2026"
• Wait for porting confirmation before cancelling Telstra

Businesses being forced off Telstra VoIP services typically need to port one or more numbers to a new provider. Our Number Porting Checker confirms your number is portable, identifies its type and category, and gives you an expected timeline before you start the process.

Each Telstra product retirement creates its own cut-off, and a migration plan that assumes the wrong date can leave your business without phones. Our Phone System Switch Planner generates a realistic timeline based on your current setup and the porting complexity involved.

Businesses on Telstra DOT (Digital Office Technology) face a separate but related deadline, DOT is being permanently retired on 30 August 2027, with stop-sell already passed as of September 2025. Our dedicated guide covers what Telstra DOT is, why it is being shut down, and how to replace it, including the migration traps to avoid and the three main options for moving your business phone system before the deadline.

If your business specifically uses T-Biz Voice or Business Voice on the nbn, see our dedicated T-Biz Voice retirement guide for that product's own end-of-sale (30 September 2025) and end-of-life (30 August 2027) dates, which differ from the broader shutdown timeline covered here.

Not sure what actually happens once you decide to switch? Read our plain-English guide to what happens when you change business phone provider, you don’t need to be technical to follow it.

Will Telstra automatically move my numbers to a new service?

No. Telstra will notify you that your service is ending, but they will not automatically port your numbers to a new provider. You need to choose a replacement service, sign up, and instruct your new provider to port your numbers from Telstra. Individual local-number ports generally take 8 to 15 business days; complex ports may take up to 30 business days.

I have a 1300 number. What happens to it?

It depends on who hosts it. If your 1300 or 1800 number is genuinely on Telstra's own retail legacy inbound platform, check with Telstra directly using the exact product name on your bill. If your 1300 or 1800 number is provided by a different carrier (Vocus, Commander, or another provider), it is not affected by Telstra's retirements just because Telstra's wholesale network is involved somewhere in the call path, your provider controls that number, not Telstra. Either way, 1300 and 1800 numbers can be ported to a new provider without your customers noticing anything changed, through ACMA's Smart Numbers framework. Do not cancel your existing service before a port is confirmed complete.

Does this affect my Telstra mobile phones?

No. The shutdown affects Telstra's SIP, VoIP, and inbound number products only. Your Telstra mobile plans, SIM cards, and mobile data services are completely separate products and are not being discontinued.

Does this affect my Telstra NBN internet?

No. The shutdown affects Telstra's voice products only. Your Telstra NBN broadband service is not affected. However, if you currently have a Telstra-provided phone service bundled with your NBN, such as a voice line through an ATA adapter connected to your modem, check whether that voice service is part of the shutdown. If it is, your internet will keep working but the phone line will stop.

How long does migration take?

From the day you sign up with a new provider to the day your numbers have ported and your new system is live, most small business migrations take 2 to 4 weeks. This includes signing up, provisioning your new phone system, testing, and completing the number port. Larger or more complex setups may take longer. Plan for at least 4 weeks to be safe, and more if you need new hardware delivered and installed.

Is Telstra shutting down all SIP and VoIP services?

No. Telstra is retiring a specific set of legacy business voice products: Telstra DOT, T-Biz Voice on the nbn, Telstra Calling for Microsoft 365, and Telstra Business SIP (stop-sell only, no confirmed shutdown date). Telstra SIP Connect remains an active, currently sold product. "Telstra VoIP shutdown" headlines describe these specific product retirements, not an exit from SIP or VoIP as a technology.

I use Vocus or Commander for my SIP service. Does this affect me?

Not directly. A Telstra product retirement applies to Telstra's own retail products. If your SIP or VoIP service is supplied by Vocus, Commander, or another carrier, that relationship is not automatically affected just because some infrastructure is shared with Telstra or NBN, or because your carrier interconnects with Telstra to complete calls. If you want certainty, ask your provider to confirm in writing that your service is not affected by any announced carrier retirement, see "Using another provider?" above.

What is Telstra's Call Termination Services (CTS), and do I have it?

Almost certainly not as a named product on your own bill. Wholesale CTS is a carrier-to-carrier service that other providers, including some VoIP resellers and MVNOs, use to terminate calls on Telstra's network. It is retiring for wholesale customers on 30 September 2026. If you are a Telstra retail SIP, DOT, or T-Biz Voice customer, that is a separate retail product with its own retirement date, check the "Who is affected" section above rather than the CTS date.

What is the difference between SIP trunking and cloud phone system?

SIP trunking connects your existing on-premise phone system (the box in your office) to the internet for calls. cloud phone system (or cloud PBX) replaces the on-premise system entirely, the phone system itself lives in the cloud. For most small businesses migrating off Telstra SIP, moving to cloud phone system is simpler and cheaper than maintaining an on-premise system with a different phone line provider.

Will my calls sound worse on VoIP?

With a properly configured system on a reliable NBN connection, call quality on cloud phone system is equal to or better than the old copper PSTN network. The risk factors are an underpowered internet connection, a router that does not prioritise voice traffic (QoS settings), and a provider with poor peering. Use the Bandwidth Calculator to check your connection, and ask any provider you are considering about their call quality SLA before signing up.

For more on the PSTN shutdown and what it means for Australian businesses more broadly, see PSTN Shutdown Australia: What Businesses Need to Know.