Microsoft 365 Integration

How 3CX Works with Microsoft 365

3CX integrates with Microsoft 365 in two key ways: contact synchronization from your Office 365 directory, and side-by-side operation with Microsoft Teams. Together, these allow your team to use 3CX for all external phone calls while continuing to use Teams for internal chat, meetings, and collaboration.

Contact Sync: Office 365 to 3CX

When contact sync is enabled, 3CX pulls contact records from your Office 365 directory and uses them for caller ID name resolution. This means when a customer calls, their name appears on your phone screen instead of just a number — even if they are not saved in your phone's local contacts. The sync runs periodically, so new contacts added to Office 365 appear in 3CX automatically.

Contact sync supports:

• Personal contacts from each user's Office 365 mailbox.
• Shared or organizational contacts from the global address list.
• Caller ID name lookup on inbound calls.
• Click-to-call from the 3CX web client using synced contact numbers.

How to Enable Contact Sync

1. Log in to the 3CX Admin Console as an administrator.
2. Navigate to Settings > Integrations or Settings > CRM (depending on your 3CX version).
3. Select Microsoft 365 from the list of available integrations.
4. Authenticate with your Microsoft 365 admin account and grant the required permissions.
5. Configure sync options — choose whether to sync personal contacts, shared contacts, or both.
6. Click Save. The initial sync will begin and contacts will appear in the 3CX phonebook within a few minutes.

Contact sync requires a Microsoft 365 Business or Enterprise plan. Microsoft 365 Personal/Family plans do not support the required API access.

Running 3CX Alongside Microsoft Teams

Many DVGVoIP customers use Microsoft Teams for internal communication — chat, video meetings, file sharing — while using 3CX to handle all external PSTN calling. This is the most common and cost-effective setup. The 3CX web client and desktop app run independently from Teams on the same computer with no conflicts.

In this configuration:

• 3CX handles all inbound and outbound phone calls (local, long distance, toll-free).
• Teams handles internal chat, presence, video meetings, and file collaboration.
• There is no need for Microsoft Teams Calling Plan or Phone System licenses — 3CX replaces the PSTN side entirely.

What About Direct Teams Calling Integration?

3CX does not integrate directly into the Teams calling interface — it operates as a separate application. You will not see your 3CX extension inside the Teams dialer. Instead, external calls are made and received through the 3CX web client, desktop app, or desk phone. This separation is intentional and keeps your phone system independent from Microsoft licensing changes.

If your team currently uses Teams Calling Plan for external calls and wants to reduce costs, switching to 3CX with DVGVoIP removes per-user licence fees while providing more advanced call management features. 3CX publishes savings of up to 80% on licensing versus per-user providers; your actual figure depends on your current contract.

DVGVoIP Advises on Best Integration

During your free assessment, DVGVoIP reviews your current Microsoft 365 setup and recommends the best integration approach. Whether you need contact sync, CRM integration, or simply want 3CX and Teams running side by side, we configure everything during deployment so your team does not have to figure it out on their own.