Why can't I activate my Sell Voice account?

Issue symptoms

In my Sell Voice and Text settings (Settings > Communication Channels > Voice and Text) I see an error message:

This job calls for some extra help! Contact Zendesk Customer Support to get Voice activated for your account, or try a different number.

Resolution steps

One sales rep can enable the Sell Voice feature for the entire account in their settings. If a sales rep experiences an error message, see the resolution steps below:

• An error message is presented if the sales rep enters a phone number they have already used to activate the Voice feature on another account. For security reasons, the same number cannot be used for Voice activation in multiple accounts. Try using a different phone number to activate Sell Voice.
• The number must be a mobile phone that can receive text messages and should include your area code.

Note: Only one user on the account can trial Sell voice using the default voice number [phone]. Every other user will have to pick their own voice number.

If you are still experiencing an error message or do not have another number available to activate the account, contact Zendesk Customer Support to enable Sell Voice.