Configure Sidecars

A sidecar is a phone accessory device that attaches to a business desk phone for advanced call handling capabilities. Sidecars simplify monitoring of large number of contacts and management of a high volume of concurrent calls. Using sidecars such as Polycom VVX Expansion Modules, a desk phone can handle additional Busy Lamp Field (BLF) keys and Speed Dial keys. With sidecars, you can accept, screen, dispatch, and monitor calls and reduce the number of lost customer calls, shorten transaction times, and increase the accuracy of call routing. For details, see our content on the complete list of 8x8 phones supporting Line Keys.

For details, see our primary sidecar user guide and our quick reference template guide.

Note: Sidecars only support BLF and Speed Dial keys.


  • Increase the number of keys on the physical phone.
  • Handle additional BLFs and Speed Dial keys.
  • Monitor large number of contacts and manage a high volume of concurrent calls.
  • Use to accept, screen, dispatch, and monitor calls.
  • Reduce the number of lost customer calls and shortens the transaction times.
  • Increase the accuracy of call routing.
  • Support 28, 30, and 40 keys sidecars.


Depending on the volume of concurrent calls, Polycom recommends not to add more than 50 BLFs per User. BLF keys require more hardware performance than Speed dials. High call volumes may show performance issues on the phone with sidecars. TLS/SRTP which is enabled by default, can be disabled to further help alleviate any potential performance issues with the physical phone.

Set up Sidecars

You can add a device that supports Sidecars, activate the device, and set up Sidecars via the Users page.

To configure Sidecars:

  1. Go to Home > Users.
  2. Edit or create a user. See how to Add VO Users.
  3. Under Voice Basic Settings, select a Device model that support Line Keys, and activate the device.
    The option to configure line keys appears next to the device.

    Note: The link only appears for devices that support Line Keys, such as VVX 300. Please refer to the list of 8x8 supported phones.

  4. In the Phone keys plan window, click +Add a sidecar. The sidecar option appears if the device is connected to a sidecar.
  5. Start adding BLF and Speed dial keys in the sidecar. See the number of keys supported for each sidecar. For better performance, we recommend you not to add more than 50 BLFs per user. For paper label sidecars and information on how to print a paper label, refer to the FAQ questions: How do I generate line key information for 40-key sidecars?
  6. Save your changes.
  7. To delete an existing sidecar, click x next to the sidecar.

Edit Sidecars

You can add, edit or delete Sidecars from the Users or Devices pages.

To edit Sidecars from the Users page:

  1. Go to Home > Users.
  2. While editing a user, go to Voice Basic Settings > Device model > Line key configuration.
  3. Make the required changes and click Save.

To edit Sidecars from the Devices page:

  1. For a quick and easy access to the Line Key configuration page, go to Home > Devices.
  2. Find an activated device that supports Line Keys and is assigned to one. Click View device report.
  3. Click next to the device that is configured with Line Keys