Teams Phone: shared devices, desk phones, and the Teams client

Purpose and prerequisites

The purpose of this article is to describe Microsoft Teams as a phone system for a small or mid-size firm, not as a reason to order a handset for every desk. Teams already lets people call other Teams users; that capability is not a public telephone network. Teams Phone is what connects those users to the PSTN so a customer can dial a ten-digit number and reach a person, a queue, or a lobby wall set. Once that decision is made, three design questions remain: how calls leave Microsoft, who receives a personal number, and whether anyone needs a physical device. The remainder of this article treats those questions separately, because conflating them is how firms buy fifty phones and still have a broken main line.

How calls leave Microsoft

For a firm of the size we usually see, four connectivity methods are honest options, and they may be mixed by site. Microsoft Calling Plans make Microsoft the carrier; that method is simplest and is fine when the firm is in one country and does not have a carrier contract it is required to keep. Operator Connect places the existing carrier in Teams admin center and is the better choice when a named telco is required and the firm does not want to own a Session Border Controller. Direct Routing means the firm, or we, run a certified SBC, and it is the method to use when analog, fax, a surviving PBX, or a stubborn carrier circuit is still in the building. Teams Phone Mobile makes the mobile number and the Teams number the same, which is worth it for people who live on a cell and never sit at a desk. Headquarters on Operator Connect and a warehouse analog gate on Direct Routing is a normal drawing. Connectivity should be chosen per site, not as one slogan for the whole company.

Shared Calling and shared devices are not the same thing

Two Microsoft ideas are often conflated because both use the word “shared.” They solve different bills. Shared Calling is one number used by many people. A resource account holds the phone number; users receive a Teams Phone license and a policy that lets them place outbound PSTN calls through that number. They do not each need a direct inward dial number or a calling plan. Shared Calling is appropriate for staff who rarely call out: warehouse, seasonal help, people whose customers already reach them on a main auto attendant. Shared Calling is not appropriate for anyone who must be called back directly, or who lives on inbound sales.

A shared device is one phone used by many hands. A lobby phone, a shop-floor phone, or a conference room that must be able to dial 911 and the front desk is licensed as Microsoft Teams Shared Device, or Shared Space, not as a person. The handset stays on the wall. Nobody signs into a personal mailbox on it. That model is the opposite of giving every employee a desk phone. Shared Calling answers who pays for the number. A shared device answers whose hands are on the plastic. Mixing those answers produces either a wall phone with a person’s voicemail or a knowledge worker with no way to be reached.

Full Teams Phone users

Knowledge workers, reception, and anyone with a published direct number receive a Teams Phone license plus a connectivity method, their own number or a clearly documented main-line and extension story, voicemail in the tenant, call forwarding, and delegation or shared-line appearance if an assistant answers for them. They use the same identity they already use for Teams chat and meetings; that single identity is the point of putting the PBX here. Reception often needs a queue or auto attendant in front of people, not a personal DID that rings into the void at lunch. The attendant should be designed first, then the humans. A personal number is an asset assigned to people who will be called on it, not a default for every licensed user.

Whether a handset is required

The default for a knowledge worker is that a handset is not required. The Teams client on a PC with a decent headset, plus the mobile application, is a complete business phone for most office and hybrid staff. Call history, transfer, hold, and voicemail live in the same place those people already work. A second device on the desk is another thing to fail, another thing to provision, and another thing that does not travel. The number is the real asset. The plastic is optional.

A certified Teams phone is warranted when at least one of the following is true. Hands and eyes are busy in a warehouse, shop, or clinic hallway, with gloves, grease, or a need to grab a handset without unlocking a PC. The desk is shared or has no PC, as in a common area, gate, waiting room, or spare office; that case is a shared-device license, not a user phone. The job is answering all day, and a dedicated receptionist who lives in a queue prefers a hardware hookswitch, a hardware mute, and a sidecar or busy-lamp look; the client can do the job, and the handset is about fatigue and habit, which are real. Hearing, motor, or policy needs require a physical control that some people cannot or will not replace with a headset and a PC. Analog or paging that has not been replaced still exists, in which case the phone is part of Direct Routing rather than a lifestyle choice. A handset should not be purchased because the firm has always had a phone on every desk, because a vendor quote included fifty of them, or because someone is anxious that Teams is not a real phone. Teams Phone is a real phone when the number and the identity are designed first.

A compact rollout

Hardware should be ordered last, against a persona list, not against headcount. The sequence we use maps personas first: main line, knowledge worker, frontline, common area, and analog leftover. PSTN connectivity is then chosen per site. Personal numbers are assigned only to people who will be called on them. Shared Calling covers the remaining licensed users who still need outbound PSTN. Shared-device licenses cover wall phones and rooms. Handsets are ordered against that list. Identity still has to be right: multifactor authentication, device policy, and no shared passwords on a lobby phone’s user account. That identity work sits in Intune and authentication.

Organizations that want this designed against a floor plan and a phone bill, rather than a slide, may contact EAC Partners.