This documentation assumes that incoming calls for all telephone numbers from the PSTN are route through the IP Office. It does not cover scenarios where the customer has telephone numbers routed directly to MS Teams through Microsoft calling plans.

• Note that the expected telephone number is a full number including international country code but no country specific international dialing prefix (except+ where indicated).

• If the customer has telephone numbers registered to Microsoft calling plans, those numbers must be migrated to one of the IP Office line providers.

• Microsoft recommend that customers configure phone numbers as full E.164 phone numbers with country code. MS Teams also supports phone numbers with extensions. MS Teams uses these match a user when the lookup against the telephone number returns more than one user.