The release of ConnecttoTeams software version 2.18.5 changes how PBX extensions are handled: all NEW extensions will now require an associated Pilot Number.
Here Are the Things You Need to Know
User Extensions must be configured with a Pilot Number after March 28, 2026. The ConnecttoTeams platform currently allows for extension numbers to be assigned to users in place of an e.164 DID/DDI. Starting with the 2.18.5 release, newly created PBX users must be configured with a unique phone number or an extension and a Pilot number. See what is a Pilot Number FAQ below.
If you are configuring a new PBX user with an e.164 DID, then there are no changes required. You will continue to select or add the e.164 Telephone Number as you currently do. The extension field can be ignored.
Any users currently configured with extensions only, must be migrated to the new schema. You can initiate this migration process at your convenience following the migration steps below.
How to Configure a Pilot Number and Extension for a New User
When configuring a new PBX user, you will notice an extra field labelled “Extension” in the Create/Edit User form (see image below). The new “Extension” field is where you must enter the extension number. The fields labelled “Phone Number” now require you to enter the Country Code and Pilot Number. The Pilot Number must be in e.164 format It will not be possible to enter an extension number in the Phone Number field.
Bulk Uploading PBX Users
The Bulk Upload file format has been revised to include a new column for extension numbers. When using the bulk upload tool, the Phone Number column must contain the Pilot Number in e.164 format (including Country Code). The bulk upload file is backwards compatible and the Extension field is only required for new users, or users that have been migrated to the Pilot Number + Extension format.
Steps to Migrate Existing Users
The migration process may only be performed by:
The Enterprise Admin, or
The Reseller (if they hold SP Management consent)
When a domain contains PBX users with extensions that require a Pilot Number, a new “Migrate” menu item will be displayed along the left side menu. Clicking the Migrate menu item will take you to a page where you can initiate the migration process.
The migration form will be prepopulated with a non-routable phone number such as the one shown in the image above (12015550101). You may replace this with a routable Pilot Number or retain the non-routable number. The non-routable Pilot Number will not affect calling capabilities - just be aware that whatever Pilot Number is saved will be displayed in the Users’ Teams Client as their Work Number (see FAQ “Why is this change being made?” below for an example).
The migration process is initiated by clicking the “Complete Migration” button. This migration process will apply the pilot number and perform a Sync Teams Users to push the changes to the Teams Admin Center.
After the migration process is started, it may take several minutes to complete. The Alerts page will keep you updated about the status of the migration process and allow you to monitor the migration events.
Once the process is complete, the Migrate Page menu item will no longer be displayed.
FAQ
What is a Pilot Number?
A pilot number is the lead directory number (DN) of an auto-attendant, call queue or trunk group — the single number that a caller dials, which then triggers the system to find an available extension/user, line or agent within a group.
Why is this change being made?
Migrating to the Pilot Number + Extension format (e.g., 14157773456 ext=1001) improves routing consistency and eliminates incorrect country code–prefixed extension displays (e.g., +11001) in the Teams client. After the migration, the PBX Users teams client will appear as seen in the “After” screenshot below.
Does the Pilot Number need to be a true routable phone number?
No, the pilot number need not be a routable number. In fact, we have prepopulated the migration form with a non-routable e.164 phone number like 1-201-555-0101. You may use this pre-populated pilot number. The non-routable Pilot Number will not affect calling capabilities - just be aware that whatever Pilot Number is saved will be displayed in the Users’ Teams Client as their Work Number (see image above for an example).
Does the Pilot Number need to come from the Phone Numbers table?
No, you can enter a number that is not in the Phone Numbers table, and it will be added there automatically.
Will my inbound calling capability be affected if I use a non-routable Pilot Number?
No, the Pilot Number does not need to be a routable number.
Do I need to make any changes to the dialing format when calling an extension from the PBX?
No. We will still accept calls with [ext]@[domain] format. For example, if the inbound call R-URI has the format of [ext]@[domain] but the user is configured with a Pilot Number and Extension, then calls will be routed correctly, however the SIP INVITE sent to Teams will include the Pilot Number like INVITE sip:+12025550123;ext=12345@sbc1.contoso.com
When should I migrate my users with extension numbers?
You can migrate your users with extension numbers at your convenience. We have created a convenient Migration Page that will allow you to perform the migration at a schedule that meets your needs. There is currently no deadline for performing this activity?
Will it be a problem if I create new users with the Pilot+Extension format before I migrate my existing users?
No. It is acceptable to have a mix of new users with Pilot_Extension formatted numbers, and older users that have not yet been migrated to the new format.
Will I be able to configure new PBX users with an extension and no Pilot Number?
No, after March 28, 2026, all new PBX users with an extension will require a corresponding Pilot Number as well.
Does this change affect users of services other than the PBX Connector.
The PilotNumber+Extension format was introduced for ACS Call App users in September 2025. After March 28, 2026 it will apply to only ACS Call App and PBX Connector users. Other ConnecttoTeams services (including SMS, SIP Trunk (DRaaS) and Operator Connect Express) do not currently support the PilotNumber+Extension format.
Currently, if my user dials another extension, that call is routed via the PBX. Will that still work, or will such calls now be handled within Teams?
Yes, it is still possible to dial by extension. These calls will be routed to the PBX in the same way that existing PBX user calls are routed.
Does the migration process require an Enterprise Global Admin?
No, any enterprise admin can run the migration process. The process can also be run by a Reseller with SP Management consent.
Is there a way to split out the users for the migration so one subset of users use one main number while another subset uses a different main number?
Yes, different users can have different pilot numbers. However, the migration tool will assign the same Pilot Number to all PBX users within the Microsoft Tenant. If you want to assign a different Pilot Number to a subset of users only, this can be done by editing the affected users individually, or applying a bulk update after the migration.