The default sender ID is the identifier from which your messages will be sent. This can be either a random shared number, a specific dedicated number, or business name.
To update the default sender ID:
1. Go to Settings and then Numbers, and then click on the Settings tab
2. Click on the edit icon next to Default Sender ID
3. From the resulting drop-down list, select your Alpha Tag
4. Click Save
If you don't want to set your Alpha Tag as the Default Sender ID, you can select to send messages from your Alpha-Tag ad-hoc when you create a new message, by selecting the option from the Sender ID list in the New Campaign window: