Legacy phone systems still power many Australian businesses, but their limitations are becoming harder to ignore.
On-prem PBX infrastructure is ageing. Support is often outsourced. Remote and hybrid work has exposed how inflexible these systems really are. They weren’t built for today’s way of working, and when they fail, the impact spreads fast.
Even simple changes can become complex. Office relocations lead to outages, third-party dependencies slow everything down, and when staff need to work from anywhere, outdated phone systems hold them back.
Now, with platforms like Telstra Calling for Office 365 being retired, businesses are being pushed to make a decision: Reinvest in ageing tech, or make the move to something more flexible and modern.
Microsoft Teams Calling offers a smarter way forward. It removes the need for physical PBX hardware, integrates directly into Microsoft 365, and enables staff to call from anywhere using their existing business number.
Why legacy phone systems are falling short
Traditional PBX systems are built around physical locations, vendor-specific equipment, and outdated workflows. While they might still function, they often rely on workarounds to meet today’s needs.
In practice, this means:
- Phone systems that fail during office moves or network changes
- Delays in updates or fixes because support is outsourced
- Limited mobility for remote or hybrid workers
- Personal mobile numbers being used as a workaround
When these limitations start affecting service delivery, the true cost becomes clear. Staff waste time chasing support or managing manual processes, call quality suffers, customer service drops, and teams grow frustrated by tools that no longer serve them.
The risks of staying put
Holding onto an outdated phone system creates risk in multiple areas. Not just in terms of technology, but across operations, support, and customer experience.
You might see it as:
- Downtime during network changes or office upgrades
- Frustration from users who cannot work flexibly
- Missed opportunities because calls go unanswered
- Inability to track or report on performance
IT teams often lack visibility into how the system is performing. Managers cannot easily adjust call flows or permissions. And when someone leaves the business, it’s not always clear what needs to be revoked or transferred.
These are not isolated issues. They affect how your business scales, serves customers, and adapts to change.
Reliable call quality also depends on network security and QoS configurations that prioritise voice traffic and maintain consistent performance across all office and remote locations.
Why now is the right time to upgrade
Most businesses have already moved email, documents and collaboration tools to the cloud – your phone system should follow.
Microsoft Teams Calling extends your existing Microsoft 365 environment to include cloud-based voice calling. It allows staff to make and receive business calls from anywhere, on any device, without relying on legacy infrastructure.
There is no need to forward calls, use personal mobiles, or log into a separate platform. Calls happen directly inside Teams, alongside chat, meetings and collaboration.
By switching now, you reduce your reliance on physical hardware, avoid future outages, and position your business for easier scaling and cost control.
Clearing up the common misconceptions
Despite its benefits, some businesses hesitate to move to Teams Calling because of outdated assumptions.
It’s only for large or complex call centres
In reality, small and mid-sized businesses often benefit the most. Teams Calling removes the overhead of on-premise hardware and makes calling easier to manage with smaller teams.
Migration will cause disruption
With the right approach, migrations are fast and smooth. Sites can be cut over with minimal downtime, often less than 30 minutes.
It will be more expensive
Many organisations reduce their telephony spend by moving to Teams Calling. Shared line pricing from Telstra and other providers is often cheaper than traditional PBX costs.
What a modern phone system should look like
A strong Teams Calling implementation gives your team more control, flexibility and simplicity.
Here’s what that can look like:
Remote and mobile access
Staff can make and receive calls from laptops, desktops or mobile devices, using their work number, while personal numbers stay private.
Integrated admin and user management
Admins can manage call flows, user permissions and setup inside the Microsoft 365 environment they already use.
Lower hardware and support overhead
There’s no need for expensive desk phones, server racks or complex infrastructure. Most users work from headsets, and IT teams manage everything from a single portal.
Scalable features on demand
Need call queues, auto attendants or analytics? Add them when required, without needing a complete system overhaul.
Microsoft Teams Calling is best deployed as part of a broader modern workplace solutions strategy, one that aligns device management, identity, collaboration tools and voice calling into a single, consistently governed environment.
What strong implementation looks like in practice
When cloud telephony is implemented well, the improvements are immediate and measurable.
You can expect:
- Minimal disruption during migration
- Significant savings by retiring legacy infrastructure
- Clear visibility into usage, support needs and service quality
- Internal teams able to manage and update the system without vendor help
These changes improve not just the phone system, but how your business communicates, supports customers and scales effectively.
How RES helps you make the move
At RES, we’ve delivered Teams Calling migrations for Australian businesses of all sizes. Our process is structured, flexible and designed to minimise disruption.
We begin by assessing your current environment, including user needs, licensing, call flows and remote work requirements. From there, we configure Teams Calling, manage the porting process, and handle deployment from end to end.
After rollout, we remain involved to provide training, answer questions and make sure the system continues to deliver value.
You won’t need to navigate the migration alone, and your team will have the support they need to adapt quickly.
What to consider next
If your phone system is still tied to physical hardware, requires vendor support for basic changes, or can’t support staff working remotely, it’s time to rethink how your business stays connected.
Start by asking:
- Are calls easily managed across office and remote setups?
- Does your team rely on workarounds like mobile forwarding?
- Is your current system helping or holding you back?
If the answers raise concerns, now is the time to act.
Microsoft Teams Calling is a mature, scalable and cost-effective alternative that integrates into the tools your team already uses.
A smarter way to communicate
Telephony is no longer a standalone system, it’s part of the broader digital workplace. And it should support your team wherever they work, not limit them.
Teams Calling is a smarter approach to communication that reduces cost, simplifies support and aligns with your business tools and goals.
If you’re ready to make the switch, RES can help you do it with clarity, speed and confidence.
Get in touch today to learn more.
Frequently Asked Questions
What is Microsoft Teams Calling?
Microsoft Teams Calling is a cloud-based business phone system that allows employees to make and receive external calls through Microsoft Teams. It brings voice calling into the same environment used for chat, meetings and collaboration. Staff can use their business number across supported computers and mobile devices without relying on a traditional phone system installed at the office.
How is Microsoft Teams Calling different from a traditional PBX?
Microsoft Teams Calling operates through the cloud rather than relying on an on-premises private branch exchange, or PBX. A PBX is the physical or software-based system that connects an organisation’s internal phones to external telephone networks. Moving calling into Teams can reduce dependence on office-based hardware, separate communication platforms and vendor support for routine system changes.
Can employees use their business phone number when working remotely?
Employees can make and receive calls through Teams using their business number when working away from the office. Calls can be handled from supported laptops, desktop computers or mobile devices, depending on the organisation’s setup. This allows staff to work more flexibly while keeping personal mobile numbers private and maintaining a consistent business identity for customers.
Does Microsoft Teams Calling require desk phones?
Microsoft Teams Calling does not require every employee to use a traditional desk phone. Many users can make and receive calls through a computer or mobile device using a suitable headset. Some workplaces may still choose compatible physical phones for reception areas, shared spaces or employees with specific requirements, so device needs should be considered during planning.
What should a business assess before moving to Teams Calling?
A business should assess its users, call flows, phone numbers, remote work needs, network capacity and licensing requirements before moving. Call flows describe how incoming calls are directed between employees, teams or departments. Reviewing these areas helps identify technical dependencies, business-critical processes and user requirements before configuration and migration begin.
Can existing business phone numbers be used with Teams Calling?
Existing business phone numbers can be used with Teams Calling through a planned number-porting process. Number porting means transferring a telephone number from one service arrangement to another. The migration should account for each number, its assigned user or function and any call-routing requirements so customer-facing communication remains properly organised.
How does the business network affect Teams call quality?
The business network directly affects the quality and reliability of voice calls made through Teams. Voice traffic depends on stable connectivity and suitable network configuration across office and remote locations. Quality of Service, commonly called QoS, is a network setting that prioritises voice traffic over less time-sensitive data to help maintain consistent call performance when network demand increases.
Will moving to Microsoft Teams Calling disrupt business operations?
A planned Teams Calling migration can limit disruption, but the outcome depends on preparation, testing and the organisation’s environment. A structured rollout should address number porting, network readiness, call routing, user setup and support arrangements. Testing important calling scenarios before wider deployment can help identify issues and give employees time to understand the new process.
Is Microsoft Teams Calling suitable for small and medium businesses?
Microsoft Teams Calling can suit small and medium businesses that want to simplify telephony and support flexible work. It may be particularly relevant when an organisation already uses Microsoft 365, depends on ageing phone infrastructure or requires external support for basic system changes. Suitability should still be assessed against user needs, network readiness and communication workflows.
How can RES. Business IT support a Teams Calling migration?
RES. Business IT can assess the existing phone environment, review user and call-flow requirements, configure Teams Calling and manage the deployment process. Its support can also include number porting, employee guidance and assistance after rollout. The approach is based on aligning the phone system with the organisation’s broader workplace, network and operational requirements.
