Microsoft Teams Phone – Replacing Legacy Telephony for a Growing Accountancy Firm
Background & Challenge
Astec was recently onboarded as the IT partner for a well-established accountancy firm, and during initial discussions, it was flagged that their outdated phone system was a key area of concern. Their on-premises solution had become a daily challenge—offering no flexibility for remote working, no clear visibility of missed calls, and limited call routing capability. On top of this, call quality was inconsistent, voicemail handling was manual, and the lack of modern features like overflow routing or mobile access was frustrating staff and clients alike.
The firm needed a modern, flexible solution that would improve both internal and external communication, with minimal disruption to their operations.
Initial Assessment
We worked closely with the business to understand their communication needs and how Teams Phone could be shaped around them:
- Team-Based Call Routing Discovery: We held workshops with different departments to understand how each team handled incoming calls, who should receive them, and what fallback behaviour should look like if teams were busy or unavailable.
- Number Porting Review: We reviewed where their existing phone numbers were held and mapped out the number porting process in line with the provider’s timelines.
- Pain Points Identified: A key issue was missed calls—particularly when a team was already on calls and there was no overflow to another group. Voicemails were often missed or left unmanaged due to lack of notifications and tracking.
- Expectation Setting: A top priority for the client was ensuring each team had reliable inbound call handling, with clear fallback behaviour and no gaps in responsiveness.
Design & Configuration
Using the assessment insights, we designed a cloud-based phone system using Microsoft Teams Phone:
- Number Porting Strategy: We planned the porting date in advance, aligned it with deployment timelines, and ensured fallback plans were in place if any delays occurred.
- Auto Attendants & Call Queues: We configured a central auto attendant to present callers with clear options, such as “Press 1 for Accounts, Press 2 for Tax.” Each selection routed to a dedicated call queue, which rang multiple team members simultaneously.
- Voicemail Setup: Voicemail was configured for each queue, with voicemail-to-email enabled to ensure messages were received and acted on promptly.
- Fallback & Overflow: Where needed, queues were configured to overflow to alternative departments or individuals after a set period—ensuring no call was left unanswered.
Pilot Testing
Before going live across the business, we conducted a controlled pilot:
- Temporary Numbers Assigned: Two teams were onboarded using temporary numbers to simulate real call flows without affecting live clients.
- Testing Auto Attendants & Call Queues: We tested all routes, ensuring calls were handled appropriately based on the menu options and fallback settings.
- Feedback Loop: We gathered feedback on the structure of the auto attendant, call queue behaviour, and usability of the Teams interface.
- Refinements Made: Based on pilot feedback, we adjusted call timings, menu wording, and queue overflow behaviour to better match user expectations.
Internal Communications & Onboarding Resources
Clear communication was key to a smooth rollout:
- Staff Comms: Astec supported the firm in announcing the upcoming switch, outlining what would change and where to find help.
- Customer Notifications: We also recommended notifying external clients via email about the upcoming phone system upgrade, with alternative contact details provided in case of any short-lived porting disruption.
- Guides: Users received quick-start guides to access Teams on desktop and mobile, how to use the features and what to expect on the day of go-live.
Deployment & User Support
Deployment was staged and supported to minimise disruption:
- Pre-Port Setup: Prior to number porting, Microsoft Teams was rolled out to all users with call functionality and licensing configured.
- Device Setup & Preferences: Headsets were paired and tested with internal Teams calls to ensure quality and comfort. We confirmed call preferences per user (mobile, desktop app, or desk phone).
- Go-Live & Porting: The number port went ahead as planned, with fallback numbers and internal call testing ready. Astec engineers were available throughout to support users, check routing, and confirm functionality.
Validation & Quality Checks
Post-deployment checks ensured the system was fully operational:
- Inbound and outbound test calls completed across all queues
- Menu and overflow routing verified
- Voicemail delivery confirmed via email alerts
- Teams functionality validated across desktop and mobile
- Final feedback collected and signed off with department heads
Outcome
- Modern, Cloud-Based Telephony: The firm now benefits from a secure, flexible calling system fully managed in the cloud.
- Improved Caller Experience: Auto attendant and call queues provide a professional first impression and ensure every call is answered or routed correctly.
- Anywhere Access: Staff can now make and receive calls from any location or device—ideal for hybrid and remote working.
- Integrated Communication: The firm benefited from seamless integration with calendars, contacts, and meeting functionality. In addition, the rollout of Teams replaced WhatsApp for internal messaging, improving data control, business security, and keeping all comms within Microsoft 365.
- Cost Savings & Simplicity: No more hardware maintenance, line rental, or manual voicemail management—just one clean, integrated platform.
“We went from a clunky, office-bound system to something modern, flexible and easy to manage. Astec made it seamless from start to finish.”
