Auto attendant vs call queue vs resource account vs Shared Calling

Verdict: Every auto attendant or call queue needs a resource account to hold its number. Only auto attendants route by business hours and holidays, so front any queue with one. Shared Calling gives numberless users the resource account's caller ID.

CriterionAuto attendantCall queueResource accountShared Calling
PurposeMenu greeting and routing front doorDistributes inbound calls to a pool of agentsDisabled sign-in account holding the number and licence for an AA or call queueGives users with no personal number an inbound and outbound identity
Off-hours and holidaysBusiness-hours and per-holiday call flowsNone; front the queue with an auto attendantn/an/a
Caller IDIts resource account numberAgents may pick the queue number or their own DIDSupplies the number shownRecipient sees the auto attendant's resource account number
Recordingn/aCompliance Recording for Call Queues records all agent-answered inbound calls with no per-agent policyn/an/a
LicenceResource account needs a Teams Phone Resource Account licenceSame, plus Queues app and Teams Premium for shared call historyTeams Phone Resource Account licence, free with Teams PhoneTeams Phone licence, voice-enabled, no personal number

Rules

Traps