What it does

A Teams phone signed in with a dedicated account rather than a person — the lobby phone, the kitchen phone, the warehouse wall phone. The device shows a stripped-back calling interface, has its own number, and can be given voicemail, call park, call group membership and queue membership like any other line.

Key facts

• The account needs a Teams Shared Devices licence, which includes the Teams Phone features. Add a Calling Plan if you're not on Direct Routing or Operator Connect, and Exchange Online Plan 2 if you want cloud voicemail on it.
• The account is a normal user account, not an Exchange resource mailbox (unlike a Teams Rooms account). Set the password manually, don't tick "Automatically create a password", and don't force a change at first sign-in.
• Sign-in options: locally on the device, remotely by code via microsoft.com/devicelogin, or by remote provisioning from the Teams admin center — the last is the sensible option at volume.
• The phone needs the IP phone policy sign-in mode CommonAreaPhoneSignIn (Set-CsTeamsIPPhonePolicy -SignInMode). Learn notes you only have to set this explicitly on accounts carrying a licence other than Teams Shared Devices, such as E3/E5.
• SearchOnCommonAreaPhoneMode restricts directory search on the device; AllowHotDesking and HotDeskingIdleTimeoutInMinutes control whether a user can temporarily sign in over the top of the common area account and for how long.
• Calling policy still applies — private calling, forwarding, simultaneous ring. Call park isn't on by default and needs a call park policy.
• Advanced calling (device firmware 1449/1.0.94.2022061702 or later) adds call park, cloud voicemail, call queue and auto attendant membership, group call pickup and forwarding rules. Turn it on in Teams devices > Phones > Configuration profiles or on the device's admin settings.
• Hotline (firmware 1449/1.0.94.2023082303 or later) autodials a fixed PSTN number or directory contact when the handset is lifted. Advanced calling has to be off to use it.
• Common area phones can't be agents in presence-based call queues because they don't report presence reliably; use attendant, serial, round robin or longest idle routing instead.
• Policy changes take effect after sign-out and sign-in, and assignments can take up to an hour to land.
• Conditional Access and interactive MFA can break sign-in on these accounts.

When to use / skip

Any phone that belongs to a place rather than a person should be a common area phone. It's cheaper than a full user licence, the UI is simpler for passers-by, and you avoid the nonsense of a "reception" user account with a mailbox and OneDrive nobody needs.

Skip it when the device is really one person's phone, or when it's a meeting room phone (that's a Teams Rooms licence and a different sign-in mode). Also think twice where staff need their own identity on the phone for most of the day — hot-desking onto a common area phone works, but if it's happening constantly, give those people user-licensed phones.

Hotline is the right answer for lift lobbies, gate phones and courtesy phones in reception. It's mutually exclusive with advanced calling, so you can't have a hotline phone that is also in a pickup group.

Configuration decisions

• Naming convention for accounts and display names — they appear in caller ID and directory search, so "Leeds Warehouse Bay 3" beats "CAP-0042".
• Whether each phone gets a DDI, or only internal extensions via dial plan; and whether inbound PSTN reaches it at all.
• Advanced calling vs hotline per device.
• Calling policy for common area phones: usually no external forwarding, voicemail only where someone actually checks it.
• Conditional Access exclusions or a device-based policy for these accounts, agreed with the identity team.
• Whether hot-desking is allowed and the idle timeout.
• Which call queues the phones join and with what routing method.

Gotchas

• Conditional Access is the number one cause of common area phones signing out overnight. Interactive MFA on a phone in a corridor isn't going to work — design an exclusion or compliant-device policy up front.
• Password expiry kills them just as quietly. Set non-expiring passwords where your policy allows, and record where the passwords live.
• Putting a common area phone in a presence-based call queue gives you calls that never ring it. Change the routing method or remove it from the queue.
• Advanced calling and hotline cancel each other out; enabling one disables the other.
• Policy changes need a sign-out/in, which on a fleet of wall phones means a site visit or a remote sign-out from the admin centre. Plan policy changes accordingly.
• Older firmware won't show the advanced calling options at all — check device firmware before assuming a feature's missing.

Consultant notes

• Do a device walk with the client: every desk phone that isn't someone's personal phone is a candidate. Lobby, kitchens, plant rooms, security desks.
• Use remote provisioning from the admin centre for anything more than a handful of devices, and give site staff a one-page "what to do when it signs out" note.
• Agree the Conditional Access approach with the identity team in the design phase, not on install day.
• Build a configuration profile per device role (lobby, warehouse, hotline) rather than per site.
• Check the device model is on the certified Teams phones list and supports advanced calling before ordering.

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Revisit when the next Teams Android phone firmware lands — the advanced calling and hotline minimum versions move, and Microsoft keeps extending what common area phones can do