Australia Teams Phone add-ons got expensive: when to move calling off per-seat licensing

01Start with the actual cost stack, not the sticker price

Microsoft is explicit that Teams Phone licensing and PSTN connectivity are separate decisions. Teams Phone gives the user the phone system capability, but PSTN access can come from Microsoft Calling Plan, Operator Connect, Direct Routing, or Teams Phone Mobile, depending on market and design choices. In Microsoft’s own guidance, Direct Routing lets you connect your own telephony infrastructure to Teams by using a certified SBC, while Operator Connect uses a certified carrier that has already integrated with Microsoft. Teams Phone licensing, PSTN connectivity options, Plan Direct Routing

For Australia buyers, the pricing trap is that the visible Microsoft plan price is usually only one layer. Microsoft’s Australia business pricing page shows Microsoft 365 Business Basic at AU$10.50 user per month, paid yearly, excluding GST. Telstra’s Critical Information Summary for Microsoft Operator Connect with Telstra shows an Individual Line Premium Calling Plan at AU$19.80 per month GST inclusive, with unlimited local, national long distance, and calls to Australian mobiles included. Those two figures alone already show why named-user calling becomes sensitive to seat count.

The key correction from the rejected draft is this: do not invent a blended per-user total unless every component is sourced. If you use Microsoft 365 Business Basic plus a Telstra Operator Connect individual line, the sourced subtotal is AU$10.50 excluding GST plus AU$19.80 including GST. Because those figures are published on different tax bases, you should not collapse them into one neat headline number without normalising tax treatment first. That is exactly how spurious figures get published.

If you are reviewing alternatives, this is where technology consulting usually adds value first: building a like-for-like cost model that separates collaboration licensing, PSTN connectivity, devices, and migration effort rather than treating them as one bundle.

• Count collaboration licences and calling licences separately
• Keep GST treatment consistent before comparing totals
• Separate named-user PSTN costs from shared infrastructure costs
• Model user classes, not one average cost for everyone

02The economic breakpoint is usually about concurrency, not headcount

Per-seat PSTN pricing makes sense when most licensed users genuinely need their own external calling entitlement, and when you want the lowest operational overhead. It starts to break when many users rarely place or receive PSTN calls, or when only a subset of the workforce is active on external calls at the same time.

That is the core economic advantage of moving calling to owned or shared telephony infrastructure through Direct Routing. Microsoft states that Direct Routing allows you to use an existing carrier and integrate third-party telephony systems through a customer-provided certified SBC. In practice, this means you can buy for concurrent usage and call routing design, not simply for employee count. Plan Direct Routing, Configure Direct Routing

A simple way to think about the breakpoint is this. If you have 300 enabled users but only 40 to 60 simultaneous external callers in the busiest periods, per-seat PSTN often looks structurally expensive. A shared SIP design lets you provision around peaks, plus safety margin. The more your organisation resembles a branch office, back office, warehouse, professional services team, or hybrid corporate environment where many people need a number but few are active concurrently, the stronger the case for moving off per-seat PSTN.

This does not mean every user should leave the Microsoft or Operator Connect model. Microsoft explicitly supports using more than one PSTN connectivity type in the same tenant. That matters. A common design is to keep executive users, mobile-heavy staff, or greenfield sites on Operator Connect, while moving the large stable population to Direct Routing and shared trunks. PSTN connectivity options

If you need a benchmark from adjacent infrastructure decisions, the same pattern appears in Microsoft 365 renewal shock in Australia: should we self-host mail now, where the wrong billing unit becomes the real problem, not the product itself.

• Good fit for per-seat PSTN: small teams, simple operations, limited internal telephony capability
• Good fit for shared infrastructure: large user base, low concurrency, mixed call demand, existing carrier relationships
• Best fit for hybrid: keep special populations on hosted PSTN, move bulk users to Direct Routing

03Three patterns where owned telephony infrastructure usually wins

First, low-use named users. If many employees need inbound reachability, voicemail, hunt groups, or occasional outbound PSTN, but not a full-time carrier entitlement, shared infrastructure is normally more efficient. You stop paying a carrier layer for each person and start paying for trunk capacity and routing design.

Second, multi-site businesses with existing voice estates. Microsoft’s Direct Routing guidance is designed for organisations that want to use existing PSTN carriers and telephony systems. If you already have SIP contracts, number ranges, and survivability requirements, replacing that with a pure per-user carrier model may simplify procurement but worsen economics. Plan Direct Routing

Third, service desks and contact-heavy shared environments. Telstra’s own Operator Connect summary distinguishes between an individual line, a shared line, and a business continuity add-on. That is a reminder that not every calling pattern maps cleanly to one named user and one flat plan. Once you are designing shared numbers, shared call handling, resilience, and overflow routing, the conversation has already moved from software licensing to telephony architecture. Microsoft Operator Connect with Telstra

For organisations already modernising adjacent infrastructure, this often sits naturally beside cloud infrastructure, API integration, and a specific telephony infrastructure workstream rather than as an isolated licence negotiation.

• Large number of lightly active PSTN users
• Existing SIP trunks, DIDs, or carrier contracts you do not want to discard
• Need for branch survivability or bespoke call routing
• Mix of users, queues, auto attendants, and shared numbers

04What you give up, and what you take on, with Direct Routing

The financial case for Direct Routing is not enough on its own. You are trading licence simplicity for infrastructure responsibility. Microsoft’s planning guide is clear about the work involved: select a Microsoft-certified SBC, configure networking, DNS, certificates, and connectivity, connect the SBC to Teams, configure voice routing and dial plans, assign policies, and validate inbound and outbound calling before rollout. Plan Direct Routing

That means the break-even point is never just a licence comparison. You need to add implementation effort, operational ownership, monitoring, failover design, and support boundaries. Microsoft also notes in its Direct Routing configuration guidance that if an issue is determined to be with the vendor SBC, the customer needs to re-engage the SBC vendor for support. That matters for internal support models. Configure Direct Routing

In practical terms, most mid-market organisations should expect four effort buckets. One, design and number strategy. Two, SBC and carrier setup. Three, migration waves, including porting and user testing. Four, operational runbooks, alerting, and support handoffs. If your internal team cannot absorb that, the alternative to per-seat PSTN is not necessarily in-house ownership. It may be a managed Direct Routing or managed SBC model.

If you are comparing delivery options, managed services can make the economics work sooner by avoiding the need to build voice operations capability internally.

• More control over routing, carriers, and number strategy
• More responsibility for design, testing, and support
• Potentially lower unit cost at scale
• Higher implementation burden than Operator Connect

05Questions to ask before your renewal locks you in

Use the renewal cycle to force the right data into the decision. Most organisations already have enough evidence, they just have not assembled it in one model.

Ask your Microsoft reseller or carrier these questions. How many users truly need a dedicated PSTN entitlement? Which user classes can share infrastructure? What are the published local prices, and are they GST inclusive or exclusive? What features require extra resource accounts, add-ons, or device spend? What is the minimum commitment period? Telstra’s support page states there is no minimum commitment required for Microsoft Operator Connect from Telstra, while its Critical Information Summary states the monthly recurring charges and inclusions for the relevant plans. Check both, and check the exact commercial paper you are being asked to sign.

Then ask the architecture questions. Can we mix PSTN connectivity types inside one tenant? Microsoft says yes. Do we have existing trunks, numbers, or contracts worth preserving? Are branch survivability and bespoke routing required? Do we need shared calling models rather than one number per user? PSTN connectivity options, Teams Phone licensing

Finally, ask the operational questions. Who owns certificates, SBC patching, failover tests, emergency call configuration, and call quality monitoring? If those answers are vague, your migration is not ready, even if the business case is strong.

For readers building a stronger sourcing process, the evaluation discipline is similar to Running a software vendor RFP that does not waste six months: define the workload, the pricing unit, the support boundary, and the exit path before comparing vendors.

• How many named users place PSTN calls weekly
• Peak concurrent calls across all sites
• What part of the bill is per user, per line, per channel, or fixed
• Whether prices are quoted GST inclusive or exclusive
• Who will run the voice platform after cutover

06A practical decision model for Australian IT leaders

Use a three-step filter.

Step one: keep per-seat PSTN if your environment is small, your users are genuinely heavy PSTN users, and you value low operational overhead more than optimising unit cost. In that case, Operator Connect remains attractive because Microsoft positions it as a simplified model where the certified operator has already completed the PSTN integration, and Telstra publishes a straightforward monthly charge for the individual line plan. PSTN connectivity options, Microsoft Operator Connect with Telstra

Step two: model a hybrid if you have mixed user populations. Leave mobile-heavy executives, small satellite teams, or temporary sites on Operator Connect. Move the large steady-state office population to Direct Routing. Microsoft supports mixed PSTN connectivity inside one tenant, so this is a supported design choice, not a workaround. PSTN connectivity options

Step three: move bulk users off per-seat PSTN when your voice requirement is really a shared infrastructure problem. The strongest signals are low concurrency, many occasional callers, retained carrier relationships, complex routing, and a large enough estate that one-off migration effort will amortise across many seats.

That is typically the point where an engineering-led voice platform approach wins. SyncTrix can help design and deliver that platform, but the decision should still stand on its own numbers: sourced licence costs, sourced carrier costs, measured usage, and a realistic implementation plan.

• Per-seat PSTN is an operations choice first, a cost choice second
• Hybrid is often the right answer, not a halfway mistake
• Direct Routing wins when the voice estate behaves like infrastructure, not like software seats