When staff already spend their day in Microsoft Teams, asking them to switch between chat, meetings and a separate desk phone system can feel like unnecessary friction. A well-planned Teams Direct Routing setup brings external calling into the platform people know, while giving the business greater control over numbers, call flows and monthly spend.
For UK businesses moving away from an ageing PBX, it can be a practical route to modern telephony without forcing a complete change in how people collaborate. The technology matters, but the best results come from making the calling experience fit the people, departments and customer journeys it is meant to support.
What Teams Direct Routing actually does
Microsoft Teams is excellent for internal conversations and meetings. Direct Routing extends it into a full business phone system by connecting Teams to the public telephone network through a Session Border Controller, usually called an SBC, and a SIP carrier.
In straightforward terms, your people can make and receive calls to ordinary phone numbers from the Teams app, whether they are in the office, at home or travelling. They can use a headset, a Teams-certified desk phone or their mobile device, depending on their role.
This approach differs from relying solely on Microsoft’s Calling Plans. Direct Routing gives organisations more choice over their voice carrier, more flexibility around number management and often a clearer path for integrating existing telephony services. It can also support more tailored call routing where reception teams, sales teams, service desks and specialist departments need different treatment.
That does not mean it is automatically the right answer for every business. A small organisation with simple requirements may find another Teams calling option perfectly suitable. Direct Routing tends to show its value when flexibility, existing number ranges, call handling requirements, cost control or resilience are higher on the agenda.
Start the Teams Direct Routing setup with the calling design
The technical connection should not be the first decision. Begin with how calls need to work in real life. Which numbers do customers use today? Who needs a direct dial number, and who should answer calls through a shared queue? What happens when a call is unanswered, when the office is closed or when the internet connection at one site fails?
These questions avoid a common mistake: recreating a legacy phone system exactly as it was, including the confusing parts. A move to Teams is a chance to simplify.
Map the main call journeys before configuration begins. For example, a main number may need a welcome message, a choice of departments and an overflow route to another team. A customer service group may require queueing, callback options and reporting. Directors may need their direct numbers to ring in Teams while their assistant can pick up selected calls.
It is also worth deciding who owns each decision. IT will normally manage identity, security and Microsoft 365 administration, but operations, finance and customer service leaders should help shape the customer-facing experience. Telephony affects far more than the IT team.
Check licences, users and domains
Each user who needs external calling requires the appropriate Teams Phone capability. The precise licensing route depends on your Microsoft agreement and the services being used, so it is sensible to review this before ordering anything.
Prepare an accurate user list as well. Include extensions, direct dial numbers, departments, locations and the type of calling each person needs. Not every employee needs the same setup. A reception team, a field engineer and a back-office colleague may all use Teams, but their calling requirements are very different.
The Microsoft 365 tenant must also be ready for voice configuration. User accounts should be properly licensed and synchronised, domains confirmed, and administrator access agreed. Sorting this groundwork early prevents delays when numbers are ready to move.
Build the right connection to the phone network
A Direct Routing service uses an SBC as the secure bridge between Microsoft Teams and the telephone network. The SBC can be hosted by your communications provider or deployed within your own environment. For most SMEs and mid-sized organisations, a managed, hosted SBC is the more practical choice because it removes a specialist infrastructure burden from internal teams.
Your provider will configure the connection between the SBC, Teams and SIP services, then apply the policies that allow authorised users to place and receive calls. The detail is technical, but the business choices behind it are clear: which users can make international calls, which sites need local numbers, how outbound caller ID should appear, and where calls should go if a service is unavailable.
Resilience deserves proper attention. Cloud calling reduces dependence on one physical phone system, but it still relies on connectivity, identity services and service design. Businesses with busy customer lines may want diverse internet connections, mobile fallback procedures or alternative routing for their main number. The right level depends on the cost of missed calls, not simply the size of the organisation.
Keep emergency calling accurate
Emergency calling is an area where assumptions can create risk. Teams users may work from several locations, and emergency services need the best available information about where a caller is. UK organisations should define emergency locations carefully, communicate procedures to staff and ensure the chosen voice solution supports their requirements for 999 calls.
This is particularly relevant for hybrid teams. A laptop can travel between sites, home offices and shared workspaces. Your policies should make clear how location information is maintained and what staff should do if they need urgent assistance.
Plan number porting around business continuity
Keeping existing numbers is usually a priority. Customers, suppliers and marketing materials may have used them for years, so number porting needs to be treated as a business change, not just an administrative task.
Create a complete inventory of every number, including main lines, direct dials, fax or alarm lines, lift phones and services connected to payment terminals or other equipment. Some may need to be retained, some replaced and some moved to a different service altogether. Finding these dependencies after a port date is where avoidable disruption begins.
Porting lead times can vary according to the current provider, number type and data quality. Match the cutover plan to the business calendar. If Monday morning is your busiest time for inbound enquiries, a weekend change with a defined support team may make more sense than a weekday switch.
Before the port completes, configure temporary routing, call queues, auto attendants and voicemail. Staff should know what will change, how to sign in on their preferred device and where to get help. Good preparation makes the first day feel uneventful, which is exactly the point.
Test the experience, not just the configuration
A successful Teams Direct Routing setup is more than a test call between two administrators. Test inbound and outbound calls, transfers, voicemail, hunt groups, call queues, caller ID presentation and calls from mobile and home networks.
Include real users in the testing group. Receptionists will spot issues with call handling, while customer service colleagues will identify whether queue announcements and overflow rules make sense. Senior leaders may care most about whether a direct call reaches them reliably across laptop, handset and mobile.
Audio quality should be checked in the locations where people actually work. Teams can perform well over modern broadband, but poor Wi-Fi design, congested connections or an unsuitable headset can still damage the caller experience. Where call quality matters, assess the network before rollout rather than waiting for complaints.
Training does not need to be a long technical session. People need practical confidence: how to answer a call, transfer it, set a status, access voicemail, use a headset and handle a customer when their connection drops. Short role-based guidance is usually more useful than a generic manual.
Manage it as an ongoing communications service
Once the system is live, review how it is performing. Look at unanswered calls, queue times, call volumes and patterns by department. A recurring issue may be a staffing problem, a call-flow problem or a simple configuration adjustment. The data is useful only when someone can turn it into a better experience for callers and staff.
As the business changes, Teams calling should change with it. New locations, acquisitions, seasonal peaks, flexible working policies and revised customer service hours all affect telephony. Direct Routing gives you room to adapt, provided the service is managed with care.
A trusted communications partner can make this less daunting by coordinating the design, number porting, implementation and ongoing support. At Bulb Tech, that means people dealing with people: clear advice before decisions are made, and practical support after the switch is complete.
The best starting point is not a list of features. It is a conversation about the calls your business cannot afford to miss, and the simpler experience your people and customers deserve.
