The Letter You Did Not Read
Product retirement notices are sent to the billing contact. In a small business, the billing contact is usually the bookkeeper, sometimes the accountant, and occasionally an employee who left in 2022 and whose mailbox forwards to nobody.
That is not negligence. It is just how business communications are addressed. But it does mean the sentence “nobody told us” and the sentence “we were told and it went to an inbox nobody reads” produce exactly the same outcome, and only one of them is a defence.
The businesses that find these migrations painless are not the ones with the biggest IT budgets. They are the ones who knew the date eight months out instead of eight weeks out.
The entire argument of this article, stated early
A note on accuracy before we go further. Several of the dates below have been reported by industry sources and integrators rather than published in one consolidated announcement, and product roadmaps do change. Treat what follows as a reason to go and verify your own position in writing, not as a substitute for doing so. Where a date is going to drive a decision, get it confirmed by email.
Which Product Are You On? A Two-Minute Test
Most business owners genuinely do not know, and the summary page of the bill will not tell them — it says “voice”, which is true and useless. Work through these four questions instead.
- Do your staff make external calls from inside Microsoft Teams, with no desk phones involved? If yes, and Telstra supplies the calling, you are almost certainly on Telstra Calling for Office 365. This is the product with the nearest reported end date, so read the Teams section below.
- Is there a Telstra-supplied box that both your internet and your phones plug into, with handsets you did not choose separately? That footprint is Telstra DOT — sold as an all-in-one package, which is exactly why it is hard to unpick.
- Is there a phone system in a cupboard that you own, with Telstra providing the lines into it? That is Business SIP: trunking rather than a phone system. You own the platform and Telstra sells you the dial tone.
- Still unsure? Open the itemised service lines on your bill, not the summary, and look for the product name: DOT, Digital Office Technology, Business SIP, SIP Connect, or a Microsoft calling line. Then email your account manager two questions: which voice product is this service, and what is its published end-of-service date?
Get the answer in writing, specifically
A verbal “you will be fine” from a friendly account manager is not a date, and it is not something you can plan around or point to later. One email, two questions, one written reply. That is the artefact you need, and it is also what every replacement provider will ask you for first.
The Three Reported Timetables
Two dates matter for any product being wound down, and confusing them is the commonest mistake. Stop-sell means it can no longer be bought, and usually no longer meaningfully changed — the service runs, frozen. End-of-service means it stops working.
| Product | Closed to new customers | Stop-sell | End of service |
|---|---|---|---|
| Calling for Office 365 | 1 November 2024 | 30 August 2026 | 30 November 2026 |
| DOT (Digital Office Technology) | — | 30 September 2025 | 30 August 2027 |
| Business SIP | — | 30 May 2025 | No published date |
There is useful precedent for how these wind-downs actually run. ISDN was the business telephony standard for twenty years. It ceased sale in June 2018, disconnections began in September 2019, and the last services came off on 31 May 2022 — nearly four years of notice. Despite that runway, the majority of affected businesses did nothing for two years and then compressed the whole project into the final quarter.
Nov 2026
Nearest reported end date — Calling for Office 365
Aug 2027
Reported end of service for DOT
4 yrs
Notice given for the ISDN shutdown — most businesses still rushed it
15 days
Typical upper end for a complex number port, before any paperwork corrections
What "Frozen" Is Already Costing You
Everybody focuses on the end-of-service date because it is dramatic. In practice, the date that has already affected your business is stop-sell, and its effects are so undramatic that they get misread as ordinary friction.
A product past stop-sell is typically closed to change. That produces a specific and recognisable set of experiences.
You could not add the two new staff properly
So they are using mobiles, and their calls are invisible to the business. No queue, no recording, no reporting, and no way to cover them when they are out.
The second location got its own arrangement
Because extending the existing system was not possible, the new site ended up on something else. Now you run two phone systems and neither can transfer to the other.
You gave up on the feature request
Someone asked for a call queue, or after-hours routing, or recording for training. The answer was that it could not be done on this service, and the request quietly died.
The price has not moved in your favour
Frozen products do not get repriced downward. The market rate for business voice has fallen considerably over the life of these platforms, and a legacy service is where that saving does not reach you.
Nothing integrates
Calls happen, and nothing about them reaches your CRM or job system unless somebody types it. On a modern platform that is a configuration step, not a project — see phone system integrations and open APIs.
You cannot answer basic questions
How many calls did we miss last month? What time of day do we lose them? Legacy small business voice products generally cannot tell you, so the decisions get made on impressions.
The reframe that matters
If any of those six paragraphs described your business, then the migration is not a compliance chore you are being forced into on somebody else's timetable. It is a project you already needed, with a deadline helpfully attached. That is a much better way to spend the budget, and a much better conversation to have internally, than “our phone company is making us”.
The Microsoft Teams Version of This Problem
If your staff call customers from inside Teams and Telstra provides the calling, you are on the product with the nearest reported deadline. This section is for you.
First, the reassurance, because this causes more alarm than it should: Microsoft Teams is not being discontinued. Your tenancy, your channels, your internal calls, your meetings — all unaffected. What ends is the carrier path that connects Teams to actual phone numbers. If nothing is done, Teams continues to work for everything except the part your customers use.
There are three routes out, and they differ mainly in how much you value keeping one app.
Another Direct Routing provider
Keep Teams exactly as it is and put a different carrier underneath it. Nothing changes on your staff's screens, which makes it the least disruptive option and the easiest to explain internally.
Trade-off: you inherit Teams calling's limits. It was built for colleagues talking to colleagues, and it remains thin on queues, IVR, recording and reporting. See Teams Phone and Direct Routing in Australia.
A cloud phone platform alongside Teams
Keep Teams for internal collaboration and put customer calls on a platform built for them. You get queues, auto-attendant, recording, reporting, AI call handling and CRM integration — the things a reception desk or a support line actually needs.
Trade-off: a second app for voice. In practice most businesses find this is what they wanted anyway, because the people answering customer calls are rarely the people living in Teams all day.
Microsoft's own calling plans
Buy the calling directly from Microsoft. Simple to reason about, one vendor, and worth pricing so you know the number.
Trade-off: compare it on total cost per user and on Australian support, not on the headline rate. This is the option where the gap between “dial tone” and “phone system” matters most.
Whichever you pick, three facts are needed before anyone can quote you: how many users need calling, which numbers you hold, and your confirmed end date. That is an hour of work and it unblocks everything else.
The Devices That Fail Silently
When the phones stop, you find out immediately. The expensive surprises are the devices that were quietly sharing that line, installed by other contractors, documented nowhere — and which fail without telling anyone.
| Device | Failure mode | Who fixes it |
|---|---|---|
| Alarm panel / monitored security | Silent. Keeps working locally, stops reaching the monitoring centre | Your monitoring provider — and ask for a written signal test after cutover |
| Back-to-base medical alert | Silent. Stops reaching the response centre | The alert provider. In any care setting this is the highest-risk item on the list |
| Fire panel dialler | Silent. May stop transmitting alarms | Fire services contractor. Long lead time — book early |
| Lift emergency phone | Stops working. A compliance and safety issue, not an inconvenience | Lift contractor. Frequently the longest lead time in the entire project |
| EFTPOS dial-up fallback | Card payments fail during an internet outage instead of falling back | Your bank or terminal provider. Most have already retired dial-up |
| Fax machine | Unreliable to non-functional over IP voice paths | Move to email-to-fax. Test with your real counterparties, not a test page |
| Door or gate intercom | Analogue intercoms wired to the legacy line stop | Replace with IP or mobile, or terminate on a supported analogue adapter |
The instruction is deliberately simple: walk the building and write down every device with a phone cable in it. Not the phones — everything else. Then one call per item to the contractor who owns that item, before any cutover date is set. That afternoon is the difference between a boring migration and an incident report.
Your Numbers: One Rule That Matters Most
Your phone numbers are yours. Number portability in Australia is regulated, providers must support it, and a valid port request cannot be refused. So the good news is that keeping your number is not the risk.
The risk is procedural. A port request is matched against the losing carrier's records, and it is rejected on any mismatch — the registered entity name rather than the trading name, an old service address, an account number transposed, or authorisation from someone without authority over the account. Each rejection costs days, and simple ports typically run 2 to 10 business days while complex ones, which is most businesses, run 5 to 15.
The one rule: never cancel the old service first
If anyone suggests cancelling the Telstra service before porting in order to save a month of line rental, ignore it. Cancelling releases the number, and a released number can be gone permanently. The port itself closes the old service — that is how the process is designed to work. One month of line rental is not a rational trade against the number printed on your vehicles, your signage and fifteen years of invoices.
The second most common loss is subtler: a number that nobody remembered to include. Businesses routinely forget a fax number, a back-office direct line, or an inherited number that still appears on old advertising and in customers' address books. Inventory every number before you request anything, including the ones you think are dead.
The Migration Nobody Notices
A phone migration done properly is invisible from outside. The trick is not technical skill; it is running the new system in parallel so that nothing is ever cut over under pressure.
- Establish the facts. Confirm your product and end date in writing. Inventory every number. Walk the building and list every device on a phone line. Half a day, and it drives everything after it.
- Start the long-lead items. Call the lift, fire, alarm and medical alert contractors now, before you talk to phone providers. They set the critical path and they cannot be hurried.
- Choose while you still have choice. Two or three quotes. Ask each provider what happens to you when their platform reaches end of life — you are in this situation because of how that question was answered last time. Check your internet has upload headroom for voice.
- Build in parallel, then port. Configure the new system, menus, queues, after-hours and voicemail on a spare number. Train staff on the app while the old system still carries every real call. Only then submit port requests. Nothing is at risk until the port completes, which is exactly the point.
- Close it out properly. Confirm every attached device still reports, in writing. Check the final bill closes the old service. Update the number everywhere it appears — website, Google profile, invoices, signage, vehicles, email footers. A working phone system nobody can find the number for is its own kind of outage.
The margin is the whole strategy
Aim to complete the port at least a month before your end-of-service date. That month converts every possible problem from an outage into an inconvenience. A rejected port becomes a resubmission rather than a crisis; a misconfigured queue becomes a Tuesday afternoon fix. Businesses that hit their date exactly are the ones who discover which of those two things they are dealing with while customers are calling.
What It Costs Against What You Pay Now
Businesses expect this migration to be an expense. Often it is not, and the reason is the freeze discussed earlier: you have been paying a legacy rate on a legacy product through a period when the market rate fell.
Rather than quote figures that will not match your situation, here is the arithmetic to run yourself. It takes about twenty minutes with a bill in front of you.
| Work out | How | Why it usually surprises people |
|---|---|---|
| Your true cost per user, per month | Total voice spend on the bill ÷ number of people who actually need a phone | Legacy bundles hide line rental, per-service charges and call spend in separate places. The combined per-user figure is often well above modern per-seat pricing |
| What you pay for calls | Sum the call charges separately from the access charges | Most current plans include calls. If call spend is a meaningful line on your bill, that is money that simply stops |
| What you pay for features you do not have | List the features quoted as add-ons or unavailable: recording, queues, IVR, reporting | These are typically included in modern platforms. Compare capability, not just price, or you will misjudge the comparison in both directions |
| Your shadow costs | Mobiles bought because staff could not be added. A second system at the second site. Missed calls you cannot measure | This is the real cost of the freeze, and it is invisible on any bill. It is also usually the biggest number on this list |
| The one-off cost | Handsets if you need them, plus contractor visits for lift, fire and alarm | The contractor visits are the genuine new expense. Handsets are often unnecessary if your team works from apps |
For the per-seat side of that comparison, what a business phone system costs in Australia has current market arithmetic, and hosted versus on-premise covers the architectural choice underneath it. If you are on Business SIP and want to keep the PBX you already own, SIP trunking in Australia is the narrower path.
Choosing So This Does Not Happen Again
You are reading this because a decision made years ago has an expiry date attached that you did not choose. The most valuable thing to extract from the experience is a better question to ask next time.
"What happens to me at end of life?"
Ask every provider. A company that owns its platform can answer directly. A reseller is answering on behalf of a vendor you have no contract with — which is precisely the position you are trying to leave.
Who actually operates the network?
Layers between you and the infrastructure are layers between a fault and a fix. Owning the network is why we can answer the end-of-life question rather than pass it on.
Where does support answer from?
Migrations generate questions at inconvenient hours. Australian-based support that knows your account is the difference between a fifteen-minute call and a ticket queue.
Can you leave?
Ask how numbers are released and how long a contract runs. A provider confident in its service does not need to trap you, and a provider that makes leaving hard has told you something important.
Does it connect to your other systems?
Open APIs are the cheapest future-proofing available, because they make every later improvement possible. Treat integration as a requirement, not a feature.
Does the platform still get developed?
The product ending underneath you now stopped being developed long before it stopped being sold. Ask what shipped in the last twelve months. Silence is an answer.
None of this is urgent this week, and that is precisely why it is worth doing this week. The ISDN wind-down gave Australian businesses four years and most still finished it in a panic — not because they lacked budget or expertise, but because a distant date never feels like this quarter's problem until it is.
So do the small version now. Find the itemised line on your bill, work out which product you are on, and email your account manager for the end date in writing. Twenty minutes, and you will know whether you have a year to plan or a quarter to move.
Frequently Asked Questions
How do I find out which Telstra business phone product I am on?
Ignore the summary page of your bill, which just says voice, and open the itemised service lines instead. Look for a product name: DOT, Digital Office Technology, Business SIP, SIP Connect, or a Microsoft-related calling line. The hardware is also a reliable clue. If staff make external calls from inside Microsoft Teams with no desk phones involved, that is Calling for Office 365. If there is a supplied box that both your internet and your phones plug into, with handsets you did not choose separately, that pattern is DOT. If there is a phone system in a cupboard that you own and the carrier just supplies lines into it, that is Business SIP. If it is still unclear, email your account manager two questions: which voice product is this service, and what is its published end-of-service date? Insist on a written answer, because a verbal reassurance is not a date you can plan around and it is also the first thing any replacement provider will ask you for.
What are the reported end dates for these products?
Calling for Office 365 closed to new customers on 1 November 2024, with stop-sell reported at 30 August 2026 and full withdrawal at 30 November 2026. DOT reached stop-sell on 30 September 2025 with end-of-service reported at 30 August 2027. Business SIP reached stop-sell on 30 May 2025 and has no publicly stated end-of-service date, which leaves existing customers on a frozen product with no published timeline. These figures come from industry reporting and integrator communications rather than a single consolidated announcement, and roadmaps do change, so treat them as a prompt to confirm your own position in writing rather than as a substitute for the notices on your account.
Does this mean Microsoft Teams is being shut down?
No, and this causes more unnecessary alarm than any other part of the story. Microsoft Teams is unaffected. Your tenancy, channels, internal calls and meetings all keep working exactly as they do now. What is ending is the carrier path that connects Teams to real external phone numbers. If you do nothing, Teams continues working for everything except making and receiving calls to and from the outside world, which is unfortunately the part your customers use. You have three ways to restore it: move to another Direct Routing provider and keep Teams unchanged on your staff's screens, run a cloud phone platform alongside Teams for customer calls, or buy calling plans directly from Microsoft. Before anyone can quote you, gather three facts: how many users need calling, which numbers you hold, and your confirmed end date.
Why does stop-sell matter if the service still works?
Because a product past stop-sell is usually frozen, and the freeze affects your business now rather than at some future date. In practice it means you cannot add users properly, so new staff end up on mobiles whose calls are invisible to the business. It means a second location gets its own separate arrangement, so you end up running two phone systems that cannot transfer to each other. It means feature requests for call queues, after-hours routing or call recording get answered with a no and quietly die. And it means you keep paying a legacy rate through a period when the market rate for business voice has fallen, because frozen products do not get repriced in your favour. If any of that sounds familiar, the migration is not a chore imposed on you, it is a project you already needed with a deadline attached.
What else stops working when a legacy phone line is disconnected?
The phones fail visibly, so they are not the problem. The risk is the devices quietly sharing that line, often installed by different contractors years ago and documented nowhere, several of which fail silently. Alarm panels and monitored security can keep working locally while no longer reaching the monitoring centre. Back-to-base medical alerts can stop reaching the response centre, which in any care setting is the highest-risk item on the list. Fire panel diallers may stop transmitting. Lift emergency phones stop entirely, which is a safety and compliance matter. EFTPOS terminals relying on dial-up fallback stop failing over. Fax becomes unreliable, and analogue door or gate intercoms stop. The practical step is to walk the building and write down every device with a phone cable in it, then make one call per item to the contractor responsible, before you set a cutover date. Lift and fire contractors usually have the longest lead times and are the true critical path.
Will I lose my phone numbers, and is there anything I must avoid doing?
Your numbers are yours and porting is regulated, so providers must support it and cannot refuse a valid request. Simple single-number ports typically take around 2 to 10 business days, and complex ports involving multiple numbers or attached services, which describes most businesses, typically take 5 to 15. Almost all delays are paperwork rather than technical: a port is matched against the losing carrier's records and is rejected on any mismatch, such as using a trading name instead of the registered entity, an old service address, a transposed account number, or authorisation from someone without authority over the account. There is one thing you must never do, and it is worth being emphatic about: do not cancel the old service before porting in order to save a month of line rental. Cancelling releases the number and a released number can be lost permanently. The port itself closes the old service. Also inventory every number you hold before submitting anything, including forgotten fax numbers and back-office lines that still appear on old advertising.
What should I ask a replacement provider so this does not happen again?
Ask what happens to you when their platform reaches end of life. You are in this position because of how that question was answered last time, and the answer tells you a great deal. A provider that owns and operates its own network can answer directly, because it is the company making the decision. A reseller is answering on behalf of a vendor you have no contract with, which is exactly the arrangement you are trying to leave. Then ask four more: who actually operates the network your calls run on, where support answers from and at what hours, how numbers are released and how long the contract runs, and what has shipped on the platform in the last twelve months. That last question is more revealing than it sounds, because the product ending underneath you now stopped being developed long before it stopped being sold. Finally, treat open APIs and CRM integration as requirements rather than features, since they are the cheapest available insurance that later improvements remain possible.
