Australia Teams Phone with shared reception and call queues: when the PSTN design makes per-user licensing the wrong model

01Why this edge case breaks the usual Teams Phone logic

Microsoft's own Shared Calling guidance says the feature is intended for users who are not heavy PSTN users and might not need a dedicated assigned number. It also states that Shared Calling can reduce costs because you do not need a dedicated phone number for every user, and that shared users place outbound PSTN calls using the phone number of a resource account associated with an auto attendant for inbound and outbound calls. See Plan for Shared Calling.

That sounds attractive for reception-heavy organisations, but there is a catch. Microsoft also requires you to assign Teams Phone licences to Shared Calling users, even though you are not assigning a number to each user. The setup steps in Configure Shared Calling begin with assigning Teams Phone licences and enabling users for voice. So Shared Calling reduces number sprawl, but not the underlying per-user telephony entitlement.

That distinction matters most where your operational model is based on a few shared business numbers and a lot of intermittent call handling. Think clinics, professional services reception teams, multi-site admin teams, dealerships, schools, service desks and branch operations. In those environments, the commercial unit that drives telephony demand is often the queue, not the person.

If you are reviewing renewals, it helps to treat this as a telephony architecture problem first, not a Microsoft licensing problem first. Similar to the mailbox edge cases covered in Australia Microsoft 365 renewals in 2026: should room mailboxes, scanners and no-reply accounts leave first, the mistake is assuming the licensing unit still matches how the service is actually used.

• Per-user licensing fits best when most calling is one person, one number, one outbound identity.
• It fits less well when most value sits in shared reception, queue routing, roster-based answering and business-level caller ID.
• Shared Calling solves some numbering friction, but it does not remove the need to license voice-enabled users.

02What Microsoft now requires for queues, auto attendants and shared calling

The licensing rules around voice applications are more structured than many older deployments assume. Microsoft says in Voice applications prerequisites and licensing that auto attendants and call queues need at least one Teams Phone licence to enable the service, plus a free Teams Phone Resource Account licence for each resource account.

Microsoft separately states in Teams Phone Resource Account licenses that all resource accounts must be assigned a Teams Phone Resource Account licence, whether or not they have a phone number, and that you should not assign a Teams Phone Standard licence to a resource account.

For outbound PSTN scenarios, Microsoft adds more conditions. In the same voice applications licensing reference, Microsoft says that if call queues or auto attendants transfer calls externally, use callback, or use representative on-behalf-of outbound calling line ID control, the resource account also needs additional PSTN connectivity, depending on the model: pay-as-you-go or Communications Credits for Microsoft-provided numbers, an online voice routing policy for Direct Routing numbers, or no extra requirement beyond the assigned number for Operator Connect numbers.

There is also an Australian-specific trap in Shared Calling. Microsoft says in Configure Shared Calling that Shared Calling is not supported for Calling Plan service phone numbers in Australia. That does not kill Shared Calling in Australia, but it does narrow which PSTN designs are viable and pushes many organisations toward Operator Connect confirmation with the carrier, or a Direct Routing style approach instead.

So the real planning model is not 'buy Teams Phone and turn on queues'. It is closer to this: map every queue, every resource account, every outbound use case, every transfer path and every emergency calling requirement, then test which PSTN connectivity model still behaves cleanly.

• Count resource accounts separately from end users.
• Check whether queues transfer externally or use callback.
• Confirm whether shared outbound calling will sit on Operator Connect, Direct Routing or another SIP-linked design.
• Validate Australian emergency calling and location handling before renewal, not after.

03The cost shape changes when the shared line is the scarce resource, not the user

The reason organisations revisit this at renewal is simple. In a queue-heavy environment, simultaneous call capacity is usually constrained by trunks, sessions or shared lines, not by how many named employees exist in Entra ID. When that is true, a per-user voice add-on can overstate actual telephony demand.

For example, Telstra's Microsoft Operator Connect with Telstra shows GST-inclusive monthly recurring charges of AU$19.80 per Individual Line, AU$69.30 per Shared Line and AU$4.40 for a Teams user business continuity add-on. Telstra's SIP Connect says plans start from AU$108 per month for 36 months. Telstra's older Business SIP also illustrates the traditional trunk logic, with monthly plan cost per voice line of AU$22, AU$40 or AU$60 depending on plan, plus AU$4 per individual SIP number. That specific product is not available to new customers after 30 May 2025, but the page is still useful because it shows how carrier telephony is priced around lines and numbers, not named users.

By contrast, Microsoft's Shared Calling documentation still starts from licensing users for Teams Phone, even if those users do not receive dedicated numbers. The more your users are occasional answerers in a reception rota, the more likely you are paying for user entitlements while operational demand is really governed by a much smaller pool of shared PSTN capacity.

This does not automatically mean 'leave Teams'. A lot of organisations still want the Teams client experience, presence and transfer behaviour. But it often does mean one of three things: keep Teams as the client and change PSTN connectivity, redesign which users are truly voice-enabled, or move queue-heavy telephony away from a pure per-user model.

If you need a parallel example of how licensing units stop matching operational reality, Australia Microsoft 365 price rise: when do shared devices and casual staff make frontline licensing the wrong answer covers the same pattern in another Microsoft cost domain.

• If ten reception and admin staff share one main outbound identity, the business may need one well-designed shared calling path, not ten fully independent voice subscriptions.
• If your peak concurrency is low but your named user count is high, carrier or SIP-style pricing can align better with actual usage.
• If every user truly needs a personal DDI, voicemail and independent routing, per-user Teams Phone usually remains easier to justify.

04Operator Connect, Direct Routing style SIP, or leave Teams for voice: the real options

In Australia, the practical choice is rarely just Teams Phone versus a completely separate PBX. It is usually one of three architectures.

First, Teams Phone with Operator Connect. Microsoft says in Plan for Operator Connect that this is a managed PSTN option where a Microsoft-certified operator manages the PSTN infrastructure and admins manage users inside Teams. This is the least disruptive path if you want to stay in Teams, avoid running your own SBC layer and still simplify carrier onboarding and number management.

Second, Teams Phone with Direct Routing style connectivity, where PSTN integration is handled through SBC-based routing and carrier SIP services. Microsoft positions Operator Connect as preferable when you do not want to deploy and maintain your own SBCs, which implicitly shows the trade-off. Direct Routing gives more control, but it brings more telephony engineering, vendor dependency and operational ownership. If you are modernising that layer, Legacy PBX to SIP trunk migration is a useful internal primer on the sequencing and traps.

Third, a non-Teams voice design for the queue-heavy part of telephony, while keeping Microsoft 365 for collaboration. This is the right question when reception, service desk or branch voice behaves more like a small contact centre than employee telephony. Microsoft Teams can still be part of the user workflow, but it may stop being the PSTN control plane for every voice workload.

A good rule is this: if your problem is mainly staff productivity, Teams-first is usually sensible. If your problem is mainly call distribution, queue logic, shared answering and shared outbound identity, telephony-first architecture usually gives a better answer.

• Choose Operator Connect when you want Teams-native administration and managed PSTN service.
• Choose Direct Routing style SIP when you need carrier flexibility, advanced routing or tighter control over voice architecture.
• Choose a separate voice platform for shared reception and queue-heavy operations when the queue is the product, not an add-on feature.

05Questions that usually expose the wrong model quickly

Before you renew or redesign, ask questions that force the architecture to show itself. These usually reveal the answer faster than a feature checklist.

Start with numbering. How many users truly need a personal external number? How many only ever answer calls from a queue or reception group? How many need outbound PSTN at all? If the answers are small, medium and very small, the default per-user model is already under pressure.

Then test concurrency. What is your peak number of simultaneous external calls across reception and queues? Not your total users, your real concurrency. Carrier and SIP designs price against this more naturally. Per-user licensing does not.

Then test call handling behaviour. Do queues transfer externally, invoke callbacks, present a shared line identity, move between sites, or need after-hours and holiday logic with different rosters? Microsoft's licensing reference makes clear that some of those features introduce extra PSTN conditions for resource accounts, which means the supposedly simple design may not be simple at all.

Then test your operating model. Who owns voice incidents, carrier faults, number porting, emergency address management and after-hours routing changes? Operator Connect reduces some of this burden. Direct Routing and SIP can increase it unless you have strong cloud infrastructure and managed services capability around the telephony stack.

Finally, test vendor lock-in. If you need to change carriers, branch topology or contact flow logic in 12 months, which design leaves you least trapped? Teams-native simplicity is valuable, but only if it remains cheaper than the rigidity it introduces.

• How many people need a personal DID?
• How many external calls happen concurrently at peak?
• Do queues transfer externally or support callback?
• Do you need business-level outbound caller ID rather than personal caller ID?
• Who will operate SBCs, dial plans, carrier incidents and emergency locations?
• What has to be portable at the next renewal?

06A practical decision framework for Australian IT leaders

Use this framework to avoid turning a pricing review into a rushed telephony migration.

Stay mainly on Teams Phone when most voice-enabled staff need individual PSTN identity, your queue layer is modest, your admin team wants the lowest operational complexity, and Operator Connect pricing is acceptable relative to your actual usage. In that case, standardise, clean up resource accounts, remove unnecessary voice-enabled users and tighten queue design. The internal post Australia Teams Phone licensing in late 2026: when do resource accounts and call queues push costs past SIP? is a good companion read.

Move to a SIP-led or Direct Routing style design when your user count is much larger than your true concurrent call demand, you need stronger control over numbering and routing, or you have queue-heavy processes that act more like customer service operations than employee telephony. Expect more design and support work, but a better match between spend and demand.

Split the architecture when the business has two different telephony realities. Keep Teams Phone for executives, managers and mobile knowledge workers who benefit from individual calling identity inside Teams. Use a separate or more carrier-centric design for reception, branches, service desks or appointment lines that revolve around shared business numbers and queue logic. This hybrid approach is often the most honest answer.

If you need outside help, the work is usually not about buying licences. It is about call-flow discovery, number inventory, emergency calling validation, queue and auto attendant rationalisation, carrier option analysis, porting runbooks and support ownership. That is why this belongs in technology consulting and telephony engineering, not only Microsoft administration.

• Do not redesign from a licence spreadsheet alone.
• Inventory numbers, queues, resource accounts and transfer paths first.
• Model peak concurrent calls before comparing commercial options.
• Choose the architecture that matches the business object being priced: person, queue or trunk.

07What to ask a vendor before you commit

Whether you are speaking to Microsoft partners, telcos or a SIP platform provider, ask for answers in writing.

Ask them to show the exact Australian support position for Shared Calling on the PSTN option they propose. Microsoft explicitly notes that Shared Calling is not supported for Calling Plan service numbers in Australia in Configure Shared Calling, and says you should confirm support with the operator if using Operator Connect.

Ask how they handle resource accounts for queues, auto attendants, callbacks and external transfers, and what extra licensing or call charging applies. If they cannot explain the resource-account side clearly, they have probably only priced named users.

Ask for the commercial model using your real data: number of main numbers, DIDs, concurrent external calls, call queues, callback usage, branch sites and after-hours routing. If the proposal is still just 'x users times y monthly fee', it is probably the wrong lens.

Ask who owns day-two operations: carrier tickets, call quality investigation, policy changes, number porting, emergency location updates and outage fallback. Telstra's Operator Connect material positions it as a managed carrier-integrated service, which may suit lean IT teams better than a self-managed SBC path.

Ask what your exit path looks like. Can numbers port cleanly? Can queues be rebuilt elsewhere without rewriting the whole user operating model? The better the answer, the lower your future renewal risk.

• Show me the Australian Shared Calling support position for this PSTN model.
• Price this against our concurrency and queue design, not only named users.
• List every resource account and what it needs for outbound behaviour.
• State who owns support, changes and carrier incidents after go-live.
• Describe the number portability and exit path.