Registering a SIP extension for 3CX requires an extension created in the 3CX portal and its SIP credentials, obtained from that extension's Phone Provisioning tab. These credentials are then entered in CCaaS to establish the SIP connection.

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Accessing SIP Extensions

SIP Extensions is accessible to accounts with Admin permissions.

1. Navigate to Admin (System) > SIP Extensions
2. All registered SIP extensions are listed on this page

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Obtaining SIP Credentials from 3CX

1. In the 3CX portal, navigate to Extensions, then select + Add to create an extension, or select an existing one
2. Select the Phone Provisioning tab
3. Under Authentication, note the SIP Extension and SIP Password — select the eye icon to reveal the password

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Registering the Extension in CCaaS

With SIP credentials in hand, the extension is added directly from the SIP Extensions page.

1. Navigate to Admin (System) > SIP Extensions
2. Select +
3. Enter the following fields using the credentials obtained from 3CX:

4. Select Save, then OK to confirm
5. Registration typically completes within a minute — select Refresh to update the status display

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Additional Extensions and Call Capacity

Rather than pooling calls through a Ring Group or Queue the way other platforms do, additional CCaaS-registered extensions are set to Accept Multiple Calls and used as direct routing targets — 3CX does not reliably route calls through a Ring Group or Queue containing a CCaaS extension.